WO2008019601A1

WO2008019601A1 - Receiver and receiving wireless signal method

Info

Publication number: WO2008019601A1
Application number: PCT/CN2007/070060
Authority: WO
Inventors: Siqing Ye
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2006-08-10
Filing date: 2007-05-29
Publication date: 2008-02-21
Also published as: CN100525123C; CN1937419A

Abstract

A receiver and receiving wireless signal method: varying gain of analog band-pass signal from input receiver under the control of analog automatic gain control (AAGC) signal; next, digitally sampling to get digital band-pass signal; then dividing the sampled digital band-pass signal into two branches, i.e. feedback branch and forward branch; detecting real signal envelope power of the digital band-pass signal in feedback branch to get envelope power and generating AAGC control signal according to the envelope power; digitally processing the digital band-pass signal in forward branch to get bit stream. By using a few samples of real signal after digitally sampling, the envelope power is directly calculated to reduce AAGC loop delay and to realize broad-band signal transient AAGC control.

Description

Receiver and method for receiving wireless signal

Technical field

The present invention relates to wireless communication technologies, and more particularly to a receiver and a method of receiving a wireless signal. Background of the invention

In a wireless communication system or radar system, it is necessary to receive a wireless signal by some means, which is called a wireless receiver or receiver. There are many types of receivers, and the dynamic range is an important indicator to measure the pros and cons of the receiver.

The dynamic range of the receiver is generally divided into simultaneous dynamic range and non-simultaneous dynamic range. Wherein, the simultaneous dynamic range is the simultaneous presence of a large signal and a small signal, and the receiver can correctly demodulate the large signal and the small signal at the same time, and the value is generally the maximum value of the large signal and small signal power ratio. Rather than simultaneous dynamic range is the ability of the receiver to correctly demodulate signals that fluctuate over time, typically in the ratio of the maximum signal power to the minimum signal power that fluctuates. The non-simultaneous dynamic range of the receiver is generally larger than its simultaneous dynamic range. This is because if the receiver and the small signal are simultaneously input and the receiver can correctly demodulate, then when the large signal and the small signal are not simultaneously input, there is no mutual interference. The problem is that the receiver is more capable of correct demodulation. In practice, the receiver can use the Analog Automatic Gain Control (AAGC) technique to achieve the goal of extending the non-simultaneous dynamic range.

At present, AAGC technology can generally be divided into two categories: one is single variable gain branch technology, and the other is multiple fixed gain branch technology.

Among them, the idea of the single variable gain branch technique is to use a branch to transmit or process the received signal, but the gain of the branch is variable.

FIG. 1 shows a prior art method for receiving a wireless signal by using a single variable gain branch. The basic structure of the receiver. As shown in FIG. 1, the receiver includes: a variable gain analog receiving channel module 101, an analog to digital conversion module 102, a real signal average power detecting module 103, an AAGC control module 104, a digital down conversion module 105, and a digital filter 106. The latter stage digital processing module 107.

The variable gain analog receiving channel module 101 generally includes a multi-stage mixing, filtering module, and amplifying module, and can change its gain under the control of the power detection and AAGC control module.

The analog to digital conversion module 102 is configured to convert the input analog band pass signal into a digital band pass signal.

The real signal average power detecting module 103 is configured to perform average power detection on the real signal input by the analog to digital conversion module 102, and output the detected average power to the AAGC control module 104.

The AAGC control module 104 is configured to determine a gain configuration based on the signal power value input by the real signal average power detecting module 103, and then change the gain of the variable gain analog receiving channel module 101 under the control of the demodulated synchronization signal.

The digital down conversion module 105 is configured to shift the frequency of the digital band pass signal input by the analog to digital conversion module 102 to a position where the center frequency is 0 frequency. The signal shifted to the 0 frequency position is divided into two parallel branches of the I path and the Q path, and the two parallel branches are collectively referred to as a complex signal or a digital I&Q signal, and are output to the digital filter 106.

The digital filter 106 is configured to perform low-pass filtering processing and output on the digital I&Q signal input by the digital down conversion module 105. The output low-pass filtered digital I&Q signal is called the baseband signal and can reflect the change of the envelope of the band-pass signal. Therefore, it is generally called digital complex envelope signal or complex envelope signal.

The post-stage digital processing module 107 is configured to perform post-level digital processing on the complex envelope signal or the baseband signal, such as filtering, decimation, demodulation, etc., and then output the bit stream. Figure 2 illustrates a basic block diagram of another receiver in the prior art that utilizes a single variable gain branch to receive wireless signals. As shown in FIG. 2, the receiver includes a variable gain analog receiving channel module 101, an analog to digital conversion module 102, a complex signal envelope power detecting module 203, an AAGC control module 104, a digital down conversion module 105, and a digital filter 106. The latter stage digital processing module 107.

The variable gain analog receiving channel module 101, the analog to digital conversion module 102, the AAGC control module 104, the digital down conversion module 105, the digital filter 106, and the subsequent digital processing module 107 are the same as the corresponding modules in FIG. The receiver includes a complex signal envelope power detection module 203 and performs complex signal based envelope power detection based on the digital I&Q signals input from the digital filter 106.

In FIG. 1, the variable gain analog receiving channel module 101, the analog to digital conversion module 102, the real signal average power detecting module 103, and the AAGC control module 104 constitute a feedback loop; in FIG. 2, the variable gain analog receiving channel module 101. The analog to digital conversion module 102, the digital down conversion module 105, the digital filter 106, the complex signal envelope power detection module 203, and the AAGC control module 104 also constitute a feedback loop.

In practical applications, the loop delay of AAGC is an important indicator to measure the performance of the receiver. In the first prior art, since the average power detection method based on the real signal is used, a signal is required, and usually more than 100 samples can obtain the average power, so that an inevitable loop delay is caused. . In the second prior art, although only one sample is needed to obtain the envelope power from the complex signal, the envelope detection is started after the digital filter, and the digital filter has a certain delay. , also caused an inevitable loop delay.

Therefore, whether it is the first or the second prior art, the AAGC loop delay is relatively long. When the AAGC is controlled according to the result of the power detection, the input signal power may not be the power of the detected signal, which makes The dynamics of the signal after AAGC control is still relatively large, which causes the AAGC control to weaken or even lose the AAGC control effect. The receiver output signal is not distorted. In addition, due to the long delay of the AAGC loop, it will be difficult to perform transient AAGC control on large-bandwidth signals, and it is also difficult to ensure that the receiver output signal is not distorted. The transient AAGC control described here means that the AAGC control is followed by the signal change. When the signal amplitude becomes larger, the attenuation of the variable gain analog receiving channel is increased. When the signal amplitude becomes smaller, the attenuation of the variable gain analog receiving channel is reduced, thereby The output of the variable gain analog receive channel is always maintained at an ideal level. Summary of the invention

The embodiment of the invention provides a receiver, which can reduce the AAGC loop delay and enhance the AAGC control capability of the receiver input signal. The technical solution proposed by the embodiment of the present invention is: A receiver, the receiver includes:

The variable gain analog receiving channel module is configured to perform variable gain processing on the analog band pass signal input by the receiver according to the AAGC control signal input by the AAGC control module, and output the signal to the analog to digital conversion module;

The analog to digital conversion module is configured to perform digital sampling processing on the analog band pass signal input by the variable gain analog receiving channel module, obtain a digital band pass signal, and output the signal to the real signal envelope power detecting module and the digital processing module;

a real signal envelope power detecting module, configured to obtain an envelope power according to a current sample value and a previous sample value of the digital band pass signal input by the analog to digital conversion module, and output the envelope power to the AAGC control module;

An AAGC control module, configured to determine an AAGC control quantity according to an envelope power input by the real signal envelope power detection module, generate an AAGC control signal from the determined AAGC control quantity, and output the signal to the variable gain analog receiving channel module;

A digital processing module for digitally processing a digital band pass signal input by the analog to digital conversion module to obtain and output a bit stream. The embodiment of the invention also provides a method for receiving a wireless signal, which can reduce the AAGC loop delay and enhance the AACC control capability of the receiver input signal. The technical solution proposed by the embodiment of the present invention is:

A method of receiving a wireless signal, the method comprising the steps of:

The analog band-pass signal of the input receiver is subjected to variable gain processing under the control of the analog automatic gain control AAGC signal, and then digitally sampled to obtain a digital band-pass signal;

The obtained digital band-pass signal is divided into a feedback branch and a forward branch, and the envelope power is obtained according to the current sample value and the previous sample value of the feedback branch, and the AAGC control amount is determined by the envelope power, and further An AAGC control signal is generated; the forward branch is digitally processed to obtain a bit stream.

In summary, the embodiment of the present invention provides a receiver and a method for receiving a wireless signal, since the envelope power of the real signal can be directly calculated by using a few sample values of the real signal after the digital sampling, Obtain a large number of sample points to calculate the average power of the real signal, and do not have to wait until the digital filtering to calculate the complex signal envelope power, which can greatly reduce the AAGC loop delay, quickly obtain the envelope power, and enhance the AAGC to the receiver. The control capability of the input signal can also perform transient AAGC control on the signal of the large wideband, so as to ensure that the output signal of the receiver is not distorted. BRIEF DESCRIPTION OF THE DRAWINGS

1 is a schematic diagram showing the basic structure of a receiver in a first prior art;

2 is a schematic diagram showing the basic structure of a receiver in a second prior art;

3 is a schematic diagram of a basic structure of a receiver in a first embodiment of the apparatus of the present invention; FIG. 4 is a schematic diagram of a basic structure of a second embodiment of a device to which the present invention is applied; 6 is a schematic diagram showing the basic structure of a seventh embodiment of an apparatus to which the solution of the present invention is applied; 7 is a schematic diagram of a basic structure of a device ninth embodiment of the present invention; FIG. 8 is a schematic diagram of a basic structure of a device ninth embodiment of the present invention; ;

10 is a flowchart of Embodiment 2 of a method for applying the solution of the present invention;

11 is a flow chart of Embodiment 5 of a method for applying the solution of the present invention;

12 is a flow chart of Embodiment 7 of a method for applying the solution of the present invention;

13 is a flow chart of Embodiment 8 of a method for applying the solution of the present invention;

Figure 14 is a flow chart of Embodiment 9 of a method of applying the solution of the present invention. Mode for carrying out the invention

The details are described in detail below with reference to the accompanying drawings and specific embodiments.

FIG. 3 is a schematic diagram showing the basic structure of a receiver in the first embodiment of the apparatus of the present invention. As shown in FIG. 3, the receiver includes a variable gain analog receiving channel module 101, an analog to digital conversion module 102, a real signal envelope power detecting module 303, an AAGC control module 104, and a digital processing module 105.

The variable gain analog receiving channel module 101 is configured to perform variable gain processing on the analog band pass signal input by the receiver according to the AAGC control signal input by the AAGC control module 104, and output the signal to the analog to digital conversion module 102.

Here, the variable gain analog receiving channel module 101 may have multiple stages of mixing, filtering, amplifying, etc., and its gain may be controlled under the control of the AAGC control module 104.

The analog to digital conversion module 102 is configured to perform digital sample processing on the analog band pass signal input from the variable gain analog receiving channel module 101, obtain a digital band pass signal, and output the signal to the real signal envelope power detecting module 303 and digital processing. Module 105.

The real signal envelope power detecting module 303 is configured to obtain an envelope power according to a current sample value and a previous sample value of the digital band pass signal input by the analog to digital conversion module, and output the envelope power to AAGC control module 104.

The preceding sample value described herein is the previous sample value or the first two sample values, that is, the present invention can directly calculate the current envelope of the real signal based on two sample values or three sample values. Power, which reduces AAGC loop delay.

The AAGC control module 104 is configured to determine an AAGC control amount according to the envelope power input by the real signal envelope power detecting module 303, and then generate an AAGC control signal by the AAGC control amount, and then output the signal to the variable gain analog receiving channel module 101.

The digital processing module 105 is configured to digitally process the digital band pass signal input by the analog to digital conversion module 102 to obtain and output a bit stream.

In practical applications, the internal structure of the digital processing module 105 is relatively complicated, and generally includes a digital down conversion module 1051, a digital filter module 1052, and a post-stage digital processing module 1053. Wherein, the digital down conversion module 1051 is configured to down-convert the digital band-pass signal input by the analog-to-digital conversion module to obtain a digital I&Q signal, and output the signal to the digital filtering module 1052; the digital filtering module 1052 is used to convert the digital down-conversion module The digital I&Q signal input by the 1051 is subjected to low-pass filtering processing to obtain a digital baseband signal, and is output to the subsequent-stage digital processing module 1053. The latter-level digital processing module 1053 is used for performing post-level digital processing by the digital filtering module, such as extraction, filtering, Demodulation and the like, obtaining and outputting a bit stream.

In this embodiment, the real signal envelope power detection module 303 can directly calculate the envelope power by using a few samples from the analog to digital conversion module 102, that is, 2 samples or 3 samples, and greatly reduce the AAGG ring. The path delay enhances the ability to control the bandpass signal input to the receiver.

In practical applications, if the system uses constant envelope modulation, ie: the information is only included in the phase change, not included in the amplitude change, and the phase characteristic of the variable gain analog receive channel module 101 does not change with the AAGC control amount, then, after The AAGC loop controlled signal does not need to be compensated for amplitude and / or phase, and can be directly digitally processed to obtain a bit stream. In practical applications, if the system uses modulation methods such as Quadrature Amplitude Modulation (QAM) and Orthogonal Frequency Division Multiplexing (OFDM), the information is included in the phase change and amplitude variation, even if the phase characteristics of the variable gain analog receive channel module 101 It does not change with the amount of AAGC control. It also needs to compensate the amplitude of the signal after the AAGC loop control so that no effective information can be lost. Of course, if the phase characteristic of the variable gain analog receiving channel module 101 changes with the amount of AAGC control, not only amplitude compensation but also phase compensation is required.

In practical applications, if the system adopts Gaussian minimum translation keying (GMSK) phase modulation, the information is only included in the phase change, not included in the amplitude variation, and the phase characteristics of the variable gain analog receiving channel module 101 are controlled by AAGC. If the quantity changes, it is necessary to separately compensate the phase so as not to lose the effective information.

Device embodiment 2

In this embodiment, the system uses constant envelope modulation, and the information is included in the amplitude variation and the phase variation. The phase characteristics of the variable gain analog receiving channel module 101 do not change with the AAGC control amount. FIG. 4 is a schematic diagram showing the basic structure of a receiver in the second embodiment of the apparatus. As shown in FIG. 4, the receiver of this embodiment includes: a variable gain analog receiving channel module 101, an analog to digital conversion module 102, a real signal envelope power detecting module 303, an AAGC control module 104, and a digital processing module 105. The digital processing module 105 further includes: a digital down conversion module 1051, a digital filter module 1052, a rear stage digital processing module 1053, and an AAGC amplitude compensation module 1054.

The structure and function of the module in the second embodiment of the device are basically the same as those in the corresponding module in FIG. 3, except that the AAGC control module 104 can be further configured to: save the gain compensation for recording the correspondence between the AAGC control amount and the gain change. The table determines the gain change according to the AAGC control amount and the gain compensation table, and outputs the determined gain change to the AAGC amplitude compensation module 1054.

The AAGC amplitude compensation module 1054 is configured to perform amplitude compensation on the signal input by the analog to digital conversion module 102 according to the gain change input by the AAGC control module 104, and Output to the digital down conversion module 1051.

In the second embodiment of the apparatus, the variable gain analog receiving channel module 101, the analog to digital conversion module 102, the real signal envelope power detecting module 303, and the AAGC control module 104 form a feedback loop, and generate an AAGC control signal to perform AAGC on the current signal in real time. Control, change the gain of the analog bandpass signal, so that the signal output from the variable gain analog receiving channel module 101 is always maintained at an ideal level, reducing the dynamics of the signal.

After the receiver receives the input analog band pass signal, the variable gain analog receive channel module 101 performs variable gain processing on the input analog band pass signal under the control of the AAGC control module 104, and outputs it to the analog to digital conversion module 102; The analog to digital conversion module 102 performs digital sampling processing on the analog band pass signal input from the variable gain analog receiving channel module 101, and divides the digital band pass signal obtained after sampling into a feedback branch and a forward branch, feedback. The branch is output to the real signal envelope power detection module 303, and the front line branch is output to the AAGC amplitude compensation module 1054; the real signal envelope power detection module 303 is based on the current sample and the previous sample input from the analog to digital conversion module 102. Or, the current sample and the last two samples are subjected to real signal envelope power detection, and the envelope power is obtained and output to the AAGC control module 104; the AAGC control module 104 is based on the envelope power input from the real signal envelope power detection module 303. Determining the AAGC control amount, on the one hand, generating an AAGC control signal according to the AAGC control amount, and outputting to the variable gain analog receiving channel module 101, On the other hand, according to the AAGC control quantity query, the gain compensation table is saved in itself, and the gain change is obtained, and is output to the AAGC amplitude compensation module 1054; the AAGC amplitude compensation module 1054 converts the analog to digital according to the gain change from the AAGC control module 104. The digital band-pass signal input by the module 102 is amplitude-compensated, and then output to the digital down-conversion module 1051. The digital down-conversion module 1051 further down-converts the input digital band-pass signal, and moves the frequency word to a center frequency of 0 frequency. Position, obtain a digital I&Q signal, and output to the digital filtering module 1052; the digital filtering module 1052 performs low-pass filtering on the digital I&Q signal input from the digital down conversion module 1051, The digital baseband signal is obtained and output to the subsequent stage digital processing module 1053. The subsequent stage digital processing module 1053 performs post-level digital processing on the digital baseband signal, such as decimation, filtering, demodulation, etc., to obtain and output a bit stream.

Device embodiment three

Based on the second embodiment of the apparatus, in practical applications, amplitude compensation can also be performed between the digital down conversion processing and the digital filtering processing.

That is to say, in the present embodiment, the AAGC amplitude compensation module 1054 is configured to perform amplitude compensation on the digital I&Q signal input from the digital down conversion module 1051 according to the gain change input by the AAGC control module 104, and output it to the digital filtering module 1052.

The functions and structures of the other modules in this embodiment are the same as those in the first embodiment of the device, and will not be described in detail herein. Device embodiment four

Based on the second embodiment of the device, in practical applications, amplitude compensation can also be performed between the digital filtering process and the subsequent digital processing.

That is, in this embodiment, the AAGC amplitude compensation module 1054 is configured to perform amplitude compensation on the digital baseband signal input from the digital filtering module 1052 according to the gain change input by the AAGC control module 104, and output the signal to the subsequent digital processing module 1053.

The functions and structures of the other modules in this embodiment are the same as those in the first embodiment of the device, and will not be described in detail herein.

In practical applications, amplitude compensation can be achieved with a digital multiplier. Since the present embodiment performs amplitude compensation after digital filtering, the burden of the digital multiplier for amplitude compensation can be reduced. Device embodiment five

FIG. 5 is a schematic diagram showing the basic structure of a receiver in the fifth embodiment of the apparatus. In this embodiment, The system uses the GMSK phase modulation method, the signal is only included in the phase change, and the phase characteristic of the variable gain analog receiving channel module 101 changes with the AAGC control amount.

As shown in FIG. 5, the embodiment includes: a variable gain analog receiving channel module 101, an analog to digital conversion module 102, a real signal envelope power detecting module 303, an AAGC control module 104, and a digital processing module 105. The digital processing module 105 further includes: a digital down conversion module 1051, a digital filter module 1052, an AAGC phase compensation module 1055, and a subsequent digital processing module 1053.

The structure and function of the module in this embodiment are basically the same as the corresponding modules in FIG. 3, except that: the AAGC control module 104 is further configured to: save a phase compensation table for recording the correspondence between the AAGC control amount and the phase change The phase change is determined according to the AAGC control amount and the phase compensation table, and the determined phase change is output to the AAGC phase compensation module 1055.

The AAGC phase compensation module 1055 is configured to phase compensate the digital baseband signal input by the digital filtering module 1052 according to the phase change input by the AAGC control module 104, and output the signal to the subsequent digital processing module 1053. Device embodiment six

Based on the fifth embodiment of the apparatus, in practical applications, phase compensation can also be performed between the digital down conversion processing and the digital filtering processing.

That is, the AAGC phase compensation module 1055 is configured to phase compensate the digital I&Q signal input by the digital down conversion module 1051 according to the phase change input by the AAGC control module 104, and output the signal to the digital filtering module 1052. The other modules in this embodiment are the same as the corresponding modules in the fifth embodiment of the device, and are not described here.

Device embodiment seven

In practical applications, it is also possible to directly use the numerically controlled oscillator in the digital down conversion module. (NCO) performs phase compensation. The NCO generally contains three configuration parameters, namely: rotation direction, frequency word and initial phase. The NCO generates a numerically controlled oscillation signal based on these three parameters and outputs it to a digital down conversion (DDC) multiplier, and the DDC multiplier will be simulated. The digital band-pass signal input to the digital conversion module 102 is multiplied by the numerically controlled oscillation signal input from the NCO, digitally down-converted, and the frequency of the digital band-pass signal is shifted to a position of 0 frequency to obtain a digital I&Q signal, and output A digital filtering module 1052 is provided. Among them, the initial phase of the NCO can determine the phase of the digitally controlled oscillator signal, which in turn affects the phase of the digital I&Q signal. Therefore, in practical applications, phase compensation can be achieved directly by changing the initial phase of the NCO.

Fig. 6 is a view showing the basic structure of the seventh embodiment of the apparatus. As shown in FIG. 6, the function and structure of the module in this embodiment are basically the same as the corresponding modules in FIG. 3, and the difference is that: the AAGC control module 104 is further configured to: save for recording AAGC control amount and phase change The phase compensation table of the correspondence relationship determines the phase change according to the AAGC control amount and the phase compensation table, and outputs the determined phase change to the NCO in the digital down conversion module 1051.

The NCO determines the initial phase based on the phase change input from the AAGC control module 104, performs phase compensation, and outputs the phase-compensated digitally controlled oscillation signal to the DDC multiplier.

In practical applications, due to the smoothing effect of the filter after DDC, the phase change of the NCO is reflected to the output signal as a gradual process, so the phase compensation method is suitable for slow phase change. Device embodiment eight

In practical applications, if the signal is included in both the amplitude variation and the phase variation, and the phase characteristics of the variable gain analog receive channel module 101 vary with the AAGC control amount. At this time, it is necessary to compensate both the amplitude of the signal and the phase of the signal.

Fig. 7 is a view showing the basic structure of a receiver in the eighth embodiment of the apparatus. In this embodiment, The system uses modulation methods such as QAM. As shown in FIG. 7, the embodiment includes: a variable gain analog receiving channel module 101, an analog to digital conversion module 102, a real signal envelope power detecting module 303, an AAGC control module 104, and a digital processing module 105. The digital processing module 105 further includes: an AAGC amplitude compensation module 1054, a digital down conversion module 1051, a digital filtering module 1052, an AAGC phase compensation module 1055, and a subsequent digital processing module 1053.

The structure and function of the module in this embodiment are basically the same as the corresponding modules in FIG. 3, except that: the AAGC control module 104 is further configured to: save a gain compensation table for recording the correspondence between the AAGC control amount and the gain change A phase compensation table for recording the correspondence between the AAGC control amount and the phase change is saved, the amplitude and phase changes are determined according to the AAGC control amount, the gain compensation table, and the phase compensation table, and the determined gain variation is output to the AAGC amplitude compensation module. 1054, outputting the phase change to the AAGC phase compensation module 1055.

The AAGC amplitude compensation module 1054 is configured to: perform amplitude compensation on the digital band pass signal input by the analog to digital conversion module 102 according to the gain change input by the AAGC control module 104, and output the digital band pass signal to the digital down conversion module 1051.

The AAGC phase compensation module 1055 is configured to: phase compensate the digital baseband signal input by the digital filtering module 1052 according to the phase change input by the AAGC control module 104, and output the signal to the subsequent digital processing module 1053.

In practical applications, if the amplitude and the phase need to be compensated, the amplitude compensation may be performed by using any one of the device embodiment 2 to the device embodiment 4, and the phase compensation is performed by using any one of the device embodiment 5 to the device embodiment 7. The amplitude compensation and phase compensation are arbitrarily combined.

Of course, if amplitude compensation and phase compensation are performed between the digital down conversion processing and the digital filtering processing, or amplitude compensation and phase compensation are performed between the digital filtering processing and the subsequent digital processing, the amplitude compensation and the phase compensation can be separately performed. , amplitude compensation and phase compensation can also be performed simultaneously. FIG. 8 is an embodiment of performing amplitude compensation and phase compensation at the same time. As shown in FIG. 8, the structure and function of the module in this embodiment are substantially the same as those of the corresponding module in FIG. 3, except that: the AAGC control module 104 Further for: saving a gain compensation table for recording the correspondence between the AAGC control amount and the gain change, and storing a phase compensation table for recording the correspondence between the AAGC control amount and the phase change, according to the AAGC control amount and the gain compensation table The phase compensation table determines the amplitude and phase changes and outputs the determined gain and phase changes to the AAGC amplitude and phase compensation module 1056.

The AAGC amplitude compensation module 1056 is configured to: perform amplitude compensation and phase compensation on the digital baseband signal input by the digital filter processing module 1052 according to the gain change and the phase change input by the AAGC control module 104, and output the digital baseband signal to the subsequent stage digital processing. Module 1053. The receiver of the present invention further provides a method for receiving a wireless signal.

9 is a flow chart of a method of receiving a wireless signal according to an embodiment of the present invention. As shown in FIG. 9, the embodiment of the present invention may include:

Step 901: Perform variable gain processing on the analog bandpass signal input to the receiver under the control of the analog automatic gain control AAGC signal.

Step 902: digitally sample the analog bandpass signal with variable gain to obtain a digital bandpass signal, and then divide the digital bandpass signal into two paths: a feedback branch and a forward branch.

Step 903: Obtain envelope power detection for the current sample and the previous sample of the feedback branch digital band pass signal, determine the AAGC control amount according to the obtained envelope power, and generate the AAGC control signal by the AAGC control amount; The digital bandpass signal of the branch is digitally processed to obtain a bit stream.

The AAGC control amount is determined according to the envelope power as described herein, and controlled according to AAGC The production of AAGC control signals by the throughput is prior art and will not be described in detail herein.

In practical applications, the digital band-pass signal of the front-end branch can be digitally processed by: digitally down-converting the digital band-pass signal, performing digital filtering, and then performing post-level digital processing. The latter digital processing described herein refers to processing such as decimation, filtering, demodulation, and the like. Of course, the actual mode of post-stage digital processing is related to the signal designed and processed by the receiver and will not be described in detail here.

In the embodiment of the present invention, the previous sample point is the previous sample point or the first two sample points of the current sample point, that is, the method for obtaining the envelope power can have two methods: One method is based on the current sample point. The envelope power is obtained from the value and the previous sample value; another method is to obtain the envelope power based on the current sample value and the first two sample values.

Referring to Figure 3, assume that the carrier frequency of the analog bandpass signal of the input receiver is Λ, the variable gain processing is still /, the analog to digital sampling frequency is /, and the relationship between / and /: is:

2k + 1

J ^c 4

1 » £ > 0 Equation 2 Here, e is a number that is much smaller than 1 but not less than 0, generally not more than 0.2, and the smaller the better. In practical applications, e is not 0 may be due to design, ie ^! And / are not equal, there are small differences; it may also be due to the system's frequency synchronization error, that is, although the sum is designed to be equal, but due to the system's frequency synchronization error, such as the transmission and reception frequency synchronization error, or the sampling clock and The incoherent error between the RF local oscillators, resulting in the actual ^! And the slight difference. In practical applications, in order to prevent aliasing and to make the following envelope calculation formula hold, the relationship between the sampling frequency and the bandwidth of the bandpass signal B can be: f _s » IB style 3

Here """ means much greater than, for example, /1 (L5 is even larger. Since the sampling frequency is assumed in the present invention, the sampling point interval is T _s . 7; and f _s satisfies:

T _s = l/f _s type 4

According to Equation 1, Equation 2, and Equation 4, you can get:

The current sample value x(n) can be expressed as:

x(n) = Re x(n) exp(j2^ _c nT _s )}

Equation 6

= i(n) cos(2« ) - q(n) sin(2« ) where,

For a digital baseband signal, it can be expressed as: x(n) = i(n) + jq(n) Equation 7

) is an I signal, q(n) Q signal, which constitutes a digital I&Q signal, that is, an I&Q complex signal, also known as a baseband signal.

According to Equation 7, we can get: = {i(n)f + (q(n)) ² Equation 8 is obtained according to Equation 5 and Equation 6:

x(n - 1) = i{n) cos(2 (n - l)T _s ) - q(n) sin(2 (n - l)T _s )

- (-1 [i(n - 1) sin(2 ) + φ - 1) cos(2 )] Under the condition of Λ / » 1, the approximation is: i(n) » i(n - l) q(n) « q(n一1) Equation 11

Thus, Equation 9 can be:

x(n - 1) « (-1)* [i(n) sin(2jf _c nT _s ) + q{n) co&{2 f _c nT _s )] Equation 12

Using Equations 6 and 12, = {i(n)) ² + {q(n)) ² « {x(n)) ² + {x(n - 1)) ²

Equation 13 is an approximate estimation formula of the first signal envelope provided by the present invention. Where l ² is the envelope power at the current sample n. It can be seen from Equation 13 that the envelope power at the current sample point n, that is, the current envelope power of the real signal, can be obtained from the current sample value x(n) and the previous sample value x(n_1).

Similarly, according to Equations 5 and 6, and using the conditions of IB » 1, we get:

0 - 2) = cos( 2 f _c (n - 2)T _s ) - q{n)s { 2 f _c (n - 2)T _s )

— i(n― 2) sin( 2nf _c nT _s ) + q(n — 2) cos( 2nf _c nT _s ) Equation 14 -i(n) sin( 2 nf _c nT _s ) + q(n) cos( 2 nf _c nT _s ) Using Equation 6, Equation 12, Equation 14, you can get

-if = {i (n - 1 )) 2 + {q (n - 1)): {η) ~ χ {η-2) λ + {χ {η _ γ) γ ₁₅ Formula 15 Formula embodiment of the present invention is An approximate estimate of the second signal envelope provided by the example. Slave

It can be seen that the envelope power at the previous sample point η - 1 can be obtained according to the current sample value χ(η) and the first two sample values, and the first two sample values described herein refer to the χ ( η - 1) and χ (η - 2). Since the interval between the η and n-1 samples is very small, it can be considered that the envelope power at the n - 1 sample is the current envelope power of the real signal, that is, the envelope power at the n sample.

In addition, in Equations 13 and 15, the equation of ? ² = +6 ² is calculated. Where is ^6 non-negative? , represents the modulus of the two-dimensional vector with ^ 6 as the component. For example, for x(n)- x(n― 2)

For Equation 15, a = is calculated in the formula ² = _fl ² +

2

When you use the polyline approximation formula, you can directly approximate the approximation. Equations 16.1 and 16.2 are examples of two polyline approximation formulas.

3

R - max(a,b) +— mm(a,b) Equation 16.1

8

7 1

R - max max(a, 3⁄4), ― max(a,b) +— mm(a,b) Equation 16.2

\ 8 2 After calculating R, the calculation of the AAGC control amount can be directly used. The maximum errors of Equation 16.1 and Equation 16.2 with respect to the ideal value of ? = a ² + are 0.57 dB and 0.26 dB, respectively. However, with respect to the sum of squares in Equations 13 and 15, Equation 16.1 and Equation 16.2 can save computational effort, further reducing the delay of the feedback loop.

In practical applications, the envelope power can be obtained directly by using Equation 13 or Equation 15, and then the calculated envelope power can be used for the calculation of the AAGC control amount; or the envelope can be directly obtained by using Equation 16.1 or Equation 16.2 based on Equation 13. Amplitude, then the calculated envelope amplitude is used for the calculation of the AAGC control amount; or, based on Equation 15, the envelope amplitude is directly obtained using Equation 16.1 or Equation 16.2, and then the calculated envelope amplitude is used for the AAGC control amount. Calculation. However, no matter which method is used, it can be implemented by digital logic, which will not be described in detail here.

In addition, in practical applications, if the system adopts constant envelope modulation, that is: the information is only included in the phase change, it is not included in the amplitude change, and the phase characteristic of the variable gain analog receiving channel module 101 does not change with the AAGC control amount. Then, the signal controlled by the AAGC loop does not need to be compensated for amplitude and / or phase, and digital processing can be directly performed to obtain a bit stream.

However, if the system uses QAM, OFDM, etc., the information is included in the phase change and amplitude change. Even if the phase characteristics of the variable gain analog receive channel module 101 do not change with the AAGC control amount, it needs to be controlled by the AAGC loop. The signal is amplitude compensated so that no valid information can be lost. Of course, if the phase characteristic of the variable gain analog receiving channel module 101 changes with the AAGC control amount, not only amplitude compensation but also phase compensation is required.

In addition, in practical applications, if the system adopts GMSK phase modulation or the like, the information is only included in the phase change, and is not included in the amplitude change, and the phase characteristic of the variable gain analog receiving channel module 101 changes with the AAGC control amount, It is necessary to separately compensate the phase so as not to lose valid information. In order to better illustrate the solution of the embodiment of the present invention, the following will be further described in detail by using the second embodiment of the method.

Method embodiment two

Fig. 4 is a view showing the basic structure of the receiver used in the embodiment. Referring to FIG. 4, in this embodiment, it is assumed that the system adopts modulation modes such as QAM and OFDM, the information is included in the phase change and the amplitude change, and the phase characteristics of the variable gain analog receiving channel module do not change with the AAGC control amount.

FIG. 10 shows a flow chart of the second embodiment of the method. As shown in FIG. 10, the method for receiving a wireless signal in this embodiment may include the following steps:

Step 1001: The analog bandpass signal input to the receiver is subjected to variable gain processing under the control of the analog automatic gain control AAGC signal.

Step 1002: Digitally sample the analog bandpass signal with variable gain to obtain a digital bandpass signal, and divide the obtained digital bandpass signal into two paths: a feedback branch and a forward branch.

Step 1003: Obtain the envelope power of the real signal at the current sample point according to the current sample point and the previous sample point of the digital band pass signal of the feedback branch; or the current sample and the first two of the digital band pass signal according to the feedback branch The sample value obtains the envelope power of the real signal at the previous sample point and uses it as an approximation of the envelope power at the current sample point.

Step 1004: Determine an AAGC control quantity according to the obtained envelope power, and generate an AAGC control signal by the AAGC control quantity. At the same time, query the saved gain compensation table according to the AAGC control quantity to obtain a gain change.

In practical applications, the AAGC control amount and gain variation can be measured in advance, and the corresponding relationship is recorded with a gain compensation table. When amplitude compensation is required, the gain compensation table can be directly queried to obtain gain variation, and then amplitude compensation is performed according to the gain variation.

The correspondence between the AAGC control amount and the gain change can be determined by measuring the system in advance, and will not be described in detail herein. Step 1005: Perform amplitude compensation on the digital band pass signal of the forward branch according to the obtained gain change.

In practical applications, the method of amplitude compensation is relatively easy to implement. It can be implemented by a digital multiplier. It is usually represented by two parallel real multipliers, and the multiplication coefficients of the two channels are the same. This same multiplication coefficient is the amplitude compensation amount.

Step 1006: Perform digital down-conversion on the amplitude-compensated digital band-pass signal, perform low-pass filtering, and then perform subsequent-stage digital processing to obtain and output a bit stream. Method embodiment three

Based on the second embodiment of the method, in the actual application, the digital bandpass signal of the forward branch may be down-converted first, and after the digital I&Q signal is obtained, the digital I&Q signal is amplitude-compensated according to the obtained gain change, and then Digitally filtering the signal for amplitude compensation. Method embodiment four

Based on the second embodiment of the method, in the actual application, the digital band pass signal of the forward branch may be down-converted and digitally filtered first, and then the digital baseband signal is obtained, and then the amplitude of the digital baseband signal is performed according to the obtained gain change. Compensation, then performing post-level digital processing to obtain a bit stream. Method embodiment five

Fig. 5 is a view showing the basic structure of the receiver in this embodiment. In this embodiment, it is assumed that the system uses the GMSK phase modulation method, the information is only included in the phase change, and the phase characteristic of the variable gain analog receiving channel module changes with the AAGC control amount.

Figure 11 shows a flow chart of the fifth embodiment of the method. As shown in FIG. 11, the method for receiving a wireless signal in this embodiment may include the following steps: Steps 1101 to 1103 are the same as steps 1001 to 1003, and are not described here.

Step 1104: Determine an AAGC control quantity according to the obtained envelope power, and generate an AAGC control signal by the AAGC control quantity. At the same time, query the saved phase compensation table according to the AAGC control quantity to obtain a phase change.

In practical applications, the correspondence between the AAGC control amount and the phase change can be measured first and recorded in the phase compensation table. When phase compensation is required, the phase compensation table can be directly queried to obtain phase changes, and then phase compensation is performed according to the phase change.

Step 1105: Perform digital down-conversion on the digital band-pass signal of the forward branch, and then perform low-pass filtering to obtain a baseband signal.

Step 1106: Perform phase compensation on the baseband signal according to the obtained phase change.

In practical applications, the phase compensation can also be implemented by a digital multiplier, usually as a complex multiplier with a gain of 1, that is, only changing the phase of the signal without changing the amplitude of the signal.

Step 1107: Perform post-stage digital processing on the phase-compensated baseband signal to obtain and output a bit stream. Method Embodiment 6

According to the fifth embodiment of the method, in the actual application, the digital band-pass signal of the forward branch can also be down-converted first, and separated into two signals of I&Q, but before being filtered, the digital I&Q signal is changed according to the obtained gain. Phase compensation is performed, and then the phase-compensated signal is digitally filtered. Method Embodiment 7

Referring to Figure 6, in practical applications, the phase compensation can also be performed directly using the NCO in the digital down conversion module. The NCO generally contains three configuration parameters, namely: direction of rotation, frequency word and The initial phase, the NCO generates a numerically controlled oscillation signal based on these three parameters, and outputs it to the DDC multiplier, which multiplies the digital band pass signal input from the analog to digital conversion module 102 and the numerically controlled oscillation signal input from the NCO. The digital down conversion process is performed, and the frequency of the digital band pass signal is moved to the position of the 0 frequency to obtain a digital I&Q signal, which is output to the digital filter module 1052. Among them, the initial phase of the NCO can determine the phase of the digitally controlled oscillator signal, which in turn affects the phase of the digital I&Q signal. Therefore, in practical applications, phase compensation can be achieved directly by changing the initial phase of the NCO.

Fig. 12 shows a flow chart of the seventh embodiment of the method. As shown in FIG. 12, the steps of the method for receiving a wireless signal in this embodiment include:

Steps 1201 to 1203 are the same as steps 1001 to 1003 in the first embodiment of the method, and are not described herein again.

Step 1204: Determine an AAGC control quantity according to the obtained envelope power, and generate an AAGC control signal by the AAGC control quantity; at the same time, query the saved phase compensation table according to the AAGC control quantity to obtain a phase change.

Step 1205: Determine the initial phase of the NCO according to the phase compensation, and combine the initial phase, the rotation direction, and the frequency word to generate a numerically controlled oscillation signal.

Step 1206: Multiply the digitally controlled oscillation signal with the digital band pass signal of the front line branch to perform digital down conversion processing to obtain a digital I&Q signal.

Step 1207: Perform digital low-pass filtering on the digital I&Q signal, and perform subsequent digital processing to obtain and output a bit stream. Method Embodiment 8

Fig. 7 is a view showing the basic structure of the receiver in this embodiment. Referring to Figure 7, if the signal is included both in the amplitude variation and in the phase variation, and the phase characteristics of the variable gain analog receive channel module vary with the AAGC control amount. In this case, you need to both The amplitude of the number is compensated, and the phase of the signal is compensated at the same time.

Figure 13 shows a flow chart of the eighth embodiment of the method. As shown in FIG. 13, the method for receiving a wireless signal in this embodiment includes the following steps:

Steps 1301 to 1303 are the same as steps 1001 to 1003 in the first embodiment of the method, and are not described herein again.

Step 1304: Determine the AAGC control quantity according to the obtained envelope power, and generate the AAGC control signal by the AAGC control quantity. At the same time, the saved gain compensation table and the phase compensation table are queried according to the AAGC control quantity to obtain the gain change and the phase change.

Step 1305: Perform amplitude compensation on the digital band pass signal of the forward branch according to the obtained gain change.

Step 1306: Perform digital down-conversion on the amplitude-compensated digital band-pass signal, perform low-pass filtering to obtain a digital baseband signal, and then phase compensate the digital baseband signal according to the obtained phase change.

Step 1307: Perform post-stage digital processing on the amplitude-compensated and phase-compensated digital baseband signals to obtain and output a bit stream.

In an actual application, if the amplitude and the phase of the signal need to be compensated, the amplitude compensation may be performed by using any one of the method embodiment 2 to the method embodiment 4, and the phase is performed by using any one of method embodiment 5 to method embodiment 7. Compensation, the method of amplitude compensation and the method of phase compensation are arbitrarily combined.

Of course, if amplitude compensation and phase compensation are performed between the digital down conversion processing and the digital filtering processing, or amplitude compensation and phase compensation are performed between the digital filtering processing and the subsequent digital processing, the amplitude compensation and the phase compensation can be separately performed. , amplitude compensation and phase compensation can also be performed simultaneously. Method embodiment nine In this embodiment, it is assumed that amplitude compensation and phase compensation are required at the same time, and the basic structure of the receiver is as shown in FIG.

Figure 14 is a flow chart of the ninth embodiment of the method. As shown in FIG. 14, the method for receiving a wireless signal in this embodiment includes the following steps:

Steps 1404 to 1404 are the same as steps 1301 to 1304, and are not described here.

Step 1405: Perform digital down conversion processing and digital filtering processing on the digital band pass signal of the forward branch to obtain a digital baseband signal.

Step 1406: Perform amplitude compensation and phase compensation on the digital baseband signal according to gain variation and phase change, and perform digital processing on the digital baseband signal after amplitude compensation and phase compensation to obtain and output a bit stream.

In practical applications, a digital multiplier can be used to simultaneously compensate the amplitude and phase of the signal. It usually appears as a complex multiplier with a gain of less than 1, which changes both the phase of the signal and the amplitude of the signal.

By applying the solution of the embodiment of the present invention, the two sample values or three sample values of the digital band pass signal obtained after digital sampling can be directly used to directly calculate the envelope power of the current real signal, which can reduce the delay of the AAGC loop. When enhancing the role of AAGC control. In addition, since the amplitude and/or phase of the signal controlled by the AAGC loop can be compensated, the information is not lost.

In conclusion, the above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Any modifications, equivalents, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

Claim

A receiver, characterized in that the receiver comprises:

A digital processing module for digitally processing a digital band pass signal input by the analog to digital conversion module to obtain and output a bit stream.

The receiver according to claim 1, wherein the digital processing module comprises: a digital down conversion module, a digital filtering module, and a subsequent digital processing module; wherein the digital down conversion module is used by The digital bandpass signal input from the analog to digital conversion module is down-converted to obtain a digital I&Q signal and output to the digital filtering module; the digital filtering module is configured to perform low-pass filtering on the digital I&Q signal input by the digital down conversion module Processing, obtaining a digital baseband signal, and outputting to a subsequent digital processing module; a subsequent digital processing module for performing digital processing by the digital filtering module to obtain and output a bit stream.

The receiver according to claim 2, wherein the receiver further comprises:

The AAGC amplitude compensation module is configured to perform amplitude compensation on the signal input by the analog to digital conversion module according to the gain change input by the AAGC control module, and output the signal to the digital down conversion module;

The AAGC control module is further configured to: save a gain compensation table for recording a correspondence between the AAGC control amount and the gain change, determine a gain change according to the AAGC control amount and the gain compensation table, and output the determined gain change to the AAGC amplitude Compensation module.

The receiver according to claim 2, wherein the receiver further comprises:

The AAGC amplitude compensation module is configured to perform amplitude compensation on the signal input by the digital down conversion module according to the gain change input by the AAGC control module, and output the signal to the digital filter module;

The receiver of claim 2, wherein the receiver further comprises:

The AAGC amplitude compensation module is configured to perform amplitude compensation on the digital baseband signal input by the digital filtering module according to the gain change input by the AAGC control module, and output the signal to the subsequent digital processing module;

The receiver according to any one of claims 2 to 5, characterized in that the receiving The machine further includes:

The AAGC phase compensation module is configured to phase compensate the digital I&Q signal input by the digital down conversion module according to the phase change input by the AAGC control module, and output the signal to the digital filtering module;

The AAGC control module is further configured to: save a phase compensation table for recording a correspondence between the AAGC control amount and the phase change, determine a phase change according to the AAGC control amount and the phase compensation table, and output the determined phase change to the AAGC phase Compensation module.

The receiver according to any one of claims 2 to 5, wherein the receiver further comprises:

The AAGC phase compensation module is configured to phase compensate the digital I&Q signal input by the digital filtering module according to the phase change input by the AAGC control module, and output the signal to the subsequent digital processing module;

The receiver according to any one of claims 2 to 5, wherein the digital down conversion module comprises a DDC multiplier and a numerically controlled oscillator NCO, the NCO being further used for: according to input by the AAGC control module The phase change is phase compensated and output to the DDC multiplier;

The AAGC control module is further configured to: save a phase compensation table for recording a correspondence between the AAGC control amount and the phase change, determine a phase change according to the AAGC control amount and the phase compensation table, and output the determined phase change to the NCO.

9. A method of receiving a wireless signal, the method comprising:

The analog bandpass signal of the input receiver is subjected to variable gain processing under the control of the analog automatic gain control AACC signal, and then digitally sampled to obtain a digital band pass signal; The obtained digital band-pass signal is divided into a feedback branch and a forward branch, and the envelope power is obtained according to the current sample value and the previous sample value of the feedback branch, and the AAGC control amount is determined by the envelope power, and further Generate AAGC control signals; digitally process the forward branches to obtain bits

,,cloud

The method according to claim 9, wherein the previous sample value is: a previous sample value or a first two sample values.

The method according to claim 10, wherein the method of digitally processing the forward branch is: first digitally down-converting the digital band-pass signal to obtain a digital I&Q signal; and then digital I&Q The signal is digitally filtered to obtain a digital baseband signal; then the subsequent digital processing is performed.

12. The method according to claim 11, wherein a gain compensation table that records a correspondence between the AAGC control amount and the gain change is set, and the digital band-pass signal of the forward branch is digitally down-converted. Previously included:

The gain compensation table is queried according to the AAGC control amount, the gain change corresponding to the AAGC control amount is obtained, and the digital band pass signal is amplitude-compensated according to the gain change.

13. The method according to claim 11, wherein a gain compensation table for recording a correspondence between the AAGC control amount and the gain change is set, and the digital down conversion processing and the digital filtering processing further include:

The gain compensation table is queried according to the AAGC control amount, and the gain change corresponding to the AAGC control amount is obtained, and the digital I&Q signal is amplitude-compensated according to the gain change.

The method according to claim 11, wherein a gain compensation table that records a correspondence between the AAGC control amount and the gain change is set, and between the digital filtering process and the subsequent digital processing, the method further includes:

The gain compensation table is queried according to the AAGC control amount, the gain change corresponding to the AAGC control amount is obtained, and the digital baseband signal is amplitude-compensated according to the gain change.

The method according to any one of claims 11 to 14, wherein a phase compensation table for recording a correspondence between AAGC control amount and phase change is set, and further between said digital down conversion processing and digital filtering processing Includes:

The phase compensation table is queried according to the AAGC control amount, the phase change corresponding to the AAGC control amount is obtained, and the digital I&Q signal is phase-compensated according to the phase change.

The method according to any one of claims 11 to 14, wherein a phase compensation table for recording a correspondence relationship between the AAGC control amount and the phase change is set, between the digital filtering process and the subsequent level digital processing, The method further includes:

The phase compensation table is queried according to the AAGC control amount, the phase change corresponding to the AAGC control amount is obtained, and the digital baseband signal is phase-compensated according to the phase change.

The method according to any one of claims 11 to 14, wherein a phase compensation table for recording a correspondence between AAGC control amount and phase change is set, and the digital down conversion processing method is: The NCO determines the direction of rotation, the frequency word and the initial phase to obtain the numerically controlled oscillation signal, and then multiplies the digital bandpass signal and the numerically controlled oscillation signal to obtain a digital I&Q signal;

The method for determining the initial phase of the NCO is: first querying the phase compensation table according to the AAGC control quantity, obtaining a phase change corresponding to the AAGC control quantity, and determining the initial phase of the NCO according to the phase change.