CA1246148A - Radio system wherein transmission power is varied according to transmission quality - Google Patents
Radio system wherein transmission power is varied according to transmission qualityInfo
- Publication number
- CA1246148A CA1246148A CA000480694A CA480694A CA1246148A CA 1246148 A CA1246148 A CA 1246148A CA 000480694 A CA000480694 A CA 000480694A CA 480694 A CA480694 A CA 480694A CA 1246148 A CA1246148 A CA 1246148A
- Authority
- CA
- Canada
- Prior art keywords
- transmission quality
- transmitting power
- radio system
- signals
- transmission
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/04—TPC
- H04W52/18—TPC being performed according to specific parameters
- H04W52/24—TPC being performed according to specific parameters using SIR [Signal to Interference Ratio] or other wireless path parameters
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/20—Arrangements for detecting or preventing errors in the information received using signal quality detector
Abstract
ABSTRACT OF THE DISCLOSURE A digital radio system with mobile and base stations is disclosed in which the base stations vary the transmitting power of the mobile stations according to the transmission quality. Criteria of the transmission quality are given. For example, in one case, the digital signals which are transmitted are encoded by an error-detecting or error-correcting code such that, in addition, the mobile stations vary the transmitting power of the base sta-tions according to the transmission quality, the rate of detected or corrected transmission errors being regarded as the transmission quality criterion. The advantage offered by the invention lies in the fact that signals which interfere with the communication but do not change the contents of the transmitted messages will not cause the receiver to increase the transmitting power. Accord-ingly, a change in transmitting power will be effected only if the useful signals cannot be reliably detected or processed.
Description
U. Langewellpott - 7 (Revision) RADIO SYSTEM
Background of the Invention The present invention relates to a radio sy~tem such as the type C radio telephone network of the German Bundespost (nFrequenz" 36, 1982, 4/5, pp. 90-99~.
For reasons of economy, it is desirable to use the same radio channels simultaneously in several areas which follow one another at the shortest possible intervals. To avoid cochannel interference, the transmitting power is usually varied according to the field strengttl measured at the receiver. However, such a measurement has the disadvantage that it is not possible to distinguish between useful and interfering , signals, so that in the presence of a weak useful signal and a strong interfering signal, for example, no transmitting-power increase will be effected.
The object of the invention is to effectively suppress cochannel interference.
The advantage offered by the invention lies in the fact that signals which interfere with the communication but do not change the contents of the transmitted messages will not cause the receiver to increase the transmitting power. Accordingly, a change in transmitting power will be effected only if the useful signals cannot be reliably detected or processed.
~1~ .,j 6~
The invention can be summarized, according to a broad aspect, as a radio system comprising mobile and base stations wherein digital signals are transmitted, and wherein the base stations vary the transmitting power of the mobile stations accor-ding to the transmission quality, characterized in that the digital signals are encoded by means of a code word such that, in addition, the mobile stations vary the transmitting power of the base sta-tions according to the transmission quality, that the received signals are correlated with said code word, and that the ratio between the average values of the highest and second-highest cor-relation peaks is regarded as the transmission quality criterion.
The invention will now be explained in mor~ deta~l with the a~d of examples. Only two stations of the radlo system will be considered. Each of the two stations varies the transmitting ; power of the respective other station. This also applies if a station cornmunicates with a plurality of stations using time-division multiplexing, for example. In that case, the transmit-ting power of this station may vary from channel to channel.
Advantageously, the transmitting power is variable in several steps, e.g., 0 dB (maximum power), 6 dB, 16 dB, 26 dB (minimum power).
In a first example, the message to be transmitted is encoded with an error-detecting or -correcting code. In a simple case, this can be done by adding parity bits. The transmission quality is judged in the receiver from the rate of the errors detected or corrected by a decoder. If the number of errors exceeds an upper limit within a few seconds, the receiver will cause an increase in transmitting power. To this end, a cor-responding signal is transmitted from the transmitter of the receiving station to the transmitting station. If the number of errors falls below a lower limit, the trans]mitting power will be reduced. Otherwise, the transmitting power remains unchanged~
~oth limits are chosen so that a character error probability of 10 4 is not exceeded~ receiving conditions permitting.
Reference should now be made to the English translation of German Patent Document DE-OS 31 18 018 published on November 25, 1982 in the name of Standard Elektrik Lorenz Aktiengesellschaft.
This document, attached hereto as an appendix, discloses a radio system in which -the signals -to be -transmitted are encoded by means of a code word. The receiver contains a correlator which corre-lates the received signals with this code word. More particu-larly, referring to Fig. 11 of the Appendix, which shows the unit for recovering the transmitted signal which is provided behind the receiver 8, it will be seen the signal is applied to 17 cor-relators 31 which are controlled by a code generator 37. One of the correlators 341 serves to synchronize the time slots. The other 16 correlators 31 are followed by 16 detectors 33, which detect maxima in the autocorrelation function. A subse~uent decision stage 34 selects the greatest from all detected maxima.
Thus, it recognizes the correct signal by the height of the cor-relation peaks. In such a system, the transmission-quality cri-terion may be the ratio of the largest to the second largest cor-~ 4~ 5175-71 relation peak. During a low-noise transmission, this magnitude relation will be large, particularly if averaged over several suc-cessively received signals, while in case of strong interference, the two values will differ only little. Analogously to the first example, the transmitter power will be changed if the magnitude xatio exceeds an upper limit or falls below a lower limit. It is adjusted by a corresponding signal in a preamble preceding the message (Fig. 5 of DE-OS 31 18 018).
In a third example, the two above-described possibili-ties of ~udging the transmission quality are combinea. An increase in transmitting power will be initiated even if only one judgment indicates a poor transm:ission qual:Lty. The transmitting power wi:ll be reducecl if both judgments are "good".
In addition, the decision to reduce the transmi-tting power can be influenced in all examples by measuring the received field strength or the phase jitter. Should the field strength fall below a predetermined minimum value, the transmitting power will not be further reduced despite good transmission quality.
Background of the Invention The present invention relates to a radio sy~tem such as the type C radio telephone network of the German Bundespost (nFrequenz" 36, 1982, 4/5, pp. 90-99~.
For reasons of economy, it is desirable to use the same radio channels simultaneously in several areas which follow one another at the shortest possible intervals. To avoid cochannel interference, the transmitting power is usually varied according to the field strengttl measured at the receiver. However, such a measurement has the disadvantage that it is not possible to distinguish between useful and interfering , signals, so that in the presence of a weak useful signal and a strong interfering signal, for example, no transmitting-power increase will be effected.
The object of the invention is to effectively suppress cochannel interference.
The advantage offered by the invention lies in the fact that signals which interfere with the communication but do not change the contents of the transmitted messages will not cause the receiver to increase the transmitting power. Accordingly, a change in transmitting power will be effected only if the useful signals cannot be reliably detected or processed.
~1~ .,j 6~
The invention can be summarized, according to a broad aspect, as a radio system comprising mobile and base stations wherein digital signals are transmitted, and wherein the base stations vary the transmitting power of the mobile stations accor-ding to the transmission quality, characterized in that the digital signals are encoded by means of a code word such that, in addition, the mobile stations vary the transmitting power of the base sta-tions according to the transmission quality, that the received signals are correlated with said code word, and that the ratio between the average values of the highest and second-highest cor-relation peaks is regarded as the transmission quality criterion.
The invention will now be explained in mor~ deta~l with the a~d of examples. Only two stations of the radlo system will be considered. Each of the two stations varies the transmitting ; power of the respective other station. This also applies if a station cornmunicates with a plurality of stations using time-division multiplexing, for example. In that case, the transmit-ting power of this station may vary from channel to channel.
Advantageously, the transmitting power is variable in several steps, e.g., 0 dB (maximum power), 6 dB, 16 dB, 26 dB (minimum power).
In a first example, the message to be transmitted is encoded with an error-detecting or -correcting code. In a simple case, this can be done by adding parity bits. The transmission quality is judged in the receiver from the rate of the errors detected or corrected by a decoder. If the number of errors exceeds an upper limit within a few seconds, the receiver will cause an increase in transmitting power. To this end, a cor-responding signal is transmitted from the transmitter of the receiving station to the transmitting station. If the number of errors falls below a lower limit, the trans]mitting power will be reduced. Otherwise, the transmitting power remains unchanged~
~oth limits are chosen so that a character error probability of 10 4 is not exceeded~ receiving conditions permitting.
Reference should now be made to the English translation of German Patent Document DE-OS 31 18 018 published on November 25, 1982 in the name of Standard Elektrik Lorenz Aktiengesellschaft.
This document, attached hereto as an appendix, discloses a radio system in which -the signals -to be -transmitted are encoded by means of a code word. The receiver contains a correlator which corre-lates the received signals with this code word. More particu-larly, referring to Fig. 11 of the Appendix, which shows the unit for recovering the transmitted signal which is provided behind the receiver 8, it will be seen the signal is applied to 17 cor-relators 31 which are controlled by a code generator 37. One of the correlators 341 serves to synchronize the time slots. The other 16 correlators 31 are followed by 16 detectors 33, which detect maxima in the autocorrelation function. A subse~uent decision stage 34 selects the greatest from all detected maxima.
Thus, it recognizes the correct signal by the height of the cor-relation peaks. In such a system, the transmission-quality cri-terion may be the ratio of the largest to the second largest cor-~ 4~ 5175-71 relation peak. During a low-noise transmission, this magnitude relation will be large, particularly if averaged over several suc-cessively received signals, while in case of strong interference, the two values will differ only little. Analogously to the first example, the transmitter power will be changed if the magnitude xatio exceeds an upper limit or falls below a lower limit. It is adjusted by a corresponding signal in a preamble preceding the message (Fig. 5 of DE-OS 31 18 018).
In a third example, the two above-described possibili-ties of ~udging the transmission quality are combinea. An increase in transmitting power will be initiated even if only one judgment indicates a poor transm:ission qual:Lty. The transmitting power wi:ll be reducecl if both judgments are "good".
In addition, the decision to reduce the transmi-tting power can be influenced in all examples by measuring the received field strength or the phase jitter. Should the field strength fall below a predetermined minimum value, the transmitting power will not be further reduced despite good transmission quality.
Claims (2)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A radio system comprising mobile and base stations wherein digital signals are transmitted, and wherein the base stations vary the transmitting power of the mobile stations accor-ding to the transmission quality, characterized in that the digital signals are encoded by means of a code word such that, in addition, the mobile stations vary the transmitting power of the base sta-tions according to the transmission quality, that the received signals are correlated with said code word, and that the ratio between the average values of the highest and second-highest cor-relation peaks is regarded as the transmission quality criterion.
2. A radio system as claimed in claim 1, characterized in that, in addition, the received field strength or the phase jitter is taken into account in varying the transmitting power.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3417233.5 | 1984-05-10 | ||
| DE19843417233 DE3417233A1 (en) | 1984-05-10 | 1984-05-10 | Radio communications system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1246148A true CA1246148A (en) | 1988-12-06 |
Family
ID=6235400
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000480694A Expired CA1246148A (en) | 1984-05-10 | 1985-05-03 | Radio system wherein transmission power is varied according to transmission quality |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP0160993B1 (en) |
| JP (1) | JPS60241336A (en) |
| AT (1) | ATE115818T1 (en) |
| AU (1) | AU578682B2 (en) |
| CA (1) | CA1246148A (en) |
| DE (2) | DE3417233A1 (en) |
| ES (1) | ES8705723A1 (en) |
| GR (1) | GR851100B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5687194A (en) | 1985-03-20 | 1997-11-11 | Interdigital Technology Corporation | Subscriber RF telephone system for providing multiple speech and/or data signals simultaneously over either a single or a plurality of RF channels |
| US5852604A (en) | 1993-09-30 | 1998-12-22 | Interdigital Technology Corporation | Modularly clustered radiotelephone system |
| US8771184B2 (en) | 1993-09-04 | 2014-07-08 | Body Science Llc | Wireless medical diagnosis and monitoring equipment |
Families Citing this family (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63226124A (en) * | 1986-10-29 | 1988-09-20 | Oki Electric Ind Co Ltd | Level control circuit for radio equipment |
| JPS6416149A (en) * | 1987-07-10 | 1989-01-19 | Fujitsu Ltd | Transmission power control system |
| DE3736020A1 (en) * | 1987-10-23 | 1989-05-03 | Bosch Gmbh Robert | RADIO NETWORK |
| IE62238B1 (en) * | 1988-02-25 | 1995-01-11 | Dieter Stephan | Process and apparatus for producing blister packs |
| SE8803094D0 (en) * | 1988-09-05 | 1988-09-05 | Joakim Nelson | EXCELLENT WIRELESS TELECOMMUNICATION SYSTEM WITH TIME, FREQUENCY AND SPACE CONTROL |
| FI85316C (en) * | 1989-05-12 | 1992-03-25 | Nokia Mobira Oy | Connection for widening the power range of a transmitter |
| SE465004B (en) * | 1989-12-18 | 1991-07-08 | Televerket | METHOD FOR DETERMINING MULTIPLE INTERFERENCES IN A MOBILE RADIO SYSTEM |
| DE4017234A1 (en) * | 1990-05-29 | 1991-12-05 | Rohde & Schwarz | SYSTEM FOR ESTABLISHING LOS RADIO CONNECTIONS FROM MOBILE TRANSMITTER / RECEIVER STATIONS TO OTHER MOBILE OR STATIONAL COUNTERSTATIONS |
| US5428821A (en) * | 1991-06-28 | 1995-06-27 | Motorola, Inc. | Base site with remote calibration capability |
| US5210771A (en) * | 1991-08-01 | 1993-05-11 | Motorola, Inc. | Multiple user spread-spectrum communication system |
| DE69231437T2 (en) * | 1991-12-26 | 2001-03-01 | Nec Corp | System for controlling the transmission power with a constant signal quality in a mobile communication network |
| JPH06326631A (en) * | 1993-05-17 | 1994-11-25 | Sony Corp | Radio communication equipment |
| JP2911090B2 (en) * | 1993-09-29 | 1999-06-23 | エヌ・ティ・ティ移動通信網株式会社 | Mobile communication base station device and mobile station device |
| US5548813A (en) * | 1994-03-24 | 1996-08-20 | Ericsson Inc. | Phased array cellular base station and associated methods for enhanced power efficiency |
| US6151310A (en) * | 1994-03-24 | 2000-11-21 | Ericsson Inc. | Dividable transmit antenna array for a cellular base station and associated method |
| US6201801B1 (en) | 1994-03-24 | 2001-03-13 | Ericsson Inc. | Polarization diversity phased array cellular base station and associated methods |
| JPH08251141A (en) * | 1995-03-11 | 1996-09-27 | Nec Corp | Transmission output control system |
| US6275711B1 (en) | 1996-10-18 | 2001-08-14 | Matsushita Electric Industrial Co., Ltd. | Method and apparatus for selecting a base station in CDMA diversity handover |
| AU733293B2 (en) * | 1996-10-18 | 2001-05-10 | Matsushita Electric Industrial Co., Ltd. | Base station for a radio communication system |
| DE19648022A1 (en) * | 1996-11-20 | 1998-05-28 | Alsthom Cge Alcatel | Circuit arrangement for the transmission of optical signals |
| DE10241359B4 (en) * | 2002-09-06 | 2005-04-28 | Siemens Ag | Method and station for generating a transmission signal for transmitting data and signaling via a radio interface |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5226805U (en) * | 1975-08-13 | 1977-02-24 | ||
| US4309771A (en) * | 1979-07-02 | 1982-01-05 | Farinon Corporation | Digital radio transmission system |
| DE3118018A1 (en) * | 1981-05-07 | 1982-11-25 | Standard Elektrik Lorenz Ag, 7000 Stuttgart | Communications system |
| GB2132452B (en) * | 1982-12-08 | 1986-10-08 | Racel Ses Limited | Radio systems |
-
1984
- 1984-05-10 DE DE19843417233 patent/DE3417233A1/en not_active Withdrawn
-
1985
- 1985-04-26 AU AU41748/85A patent/AU578682B2/en not_active Ceased
- 1985-05-03 CA CA000480694A patent/CA1246148A/en not_active Expired
- 1985-05-07 GR GR851100A patent/GR851100B/el unknown
- 1985-05-07 JP JP60096544A patent/JPS60241336A/en active Pending
- 1985-05-09 DE DE3587961T patent/DE3587961D1/en not_active Expired - Fee Related
- 1985-05-09 AT AT85105680T patent/ATE115818T1/en not_active IP Right Cessation
- 1985-05-09 EP EP85105680A patent/EP0160993B1/en not_active Expired - Lifetime
- 1985-05-10 ES ES543031A patent/ES8705723A1/en not_active Expired
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5687194A (en) | 1985-03-20 | 1997-11-11 | Interdigital Technology Corporation | Subscriber RF telephone system for providing multiple speech and/or data signals simultaneously over either a single or a plurality of RF channels |
| US5734678A (en) | 1985-03-20 | 1998-03-31 | Interdigital Technology Corporation | Subscriber RF telephone system for providing multiple speech and/or data signals simultaneously over either a single or a plurality of RF channels |
| US6014374A (en) | 1985-03-20 | 2000-01-11 | Interdigital Technology Corporation | Subscriber RF telephone system for providing multiple speech and/or data signals simultaneously over either a single or a plurality of RF channels |
| US6282180B1 (en) | 1985-03-20 | 2001-08-28 | Interdigital Technology Corporation | Subscriber RF telephone system for providing multiple speech and/or data signals simultaneously over either a single or a plurality of RF channels |
| US6393002B1 (en) | 1985-03-20 | 2002-05-21 | Interdigital Technology Corporation | Subscriber RF telephone system for providing multiple speech and/or data signals simultaneously over either a single or a plurality of RF channels |
| US6771667B2 (en) | 1985-03-20 | 2004-08-03 | Interdigital Technology Corporation | Subscriber RF telephone system for providing multiple speech and/or data signals simultaneously over either a single or a plurality of RF channels |
| US8771184B2 (en) | 1993-09-04 | 2014-07-08 | Body Science Llc | Wireless medical diagnosis and monitoring equipment |
| US5852604A (en) | 1993-09-30 | 1998-12-22 | Interdigital Technology Corporation | Modularly clustered radiotelephone system |
| US6208630B1 (en) | 1993-09-30 | 2001-03-27 | Interdigital Technology Corporation | Modulary clustered radiotelephone system |
| US6496488B1 (en) | 1993-09-30 | 2002-12-17 | Interdigital Technology Corporation | Modularly clustered radiotelephone system |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60241336A (en) | 1985-11-30 |
| EP0160993A2 (en) | 1985-11-13 |
| GR851100B (en) | 1985-11-25 |
| ES8705723A1 (en) | 1987-04-01 |
| ES543031A0 (en) | 1987-04-01 |
| EP0160993B1 (en) | 1994-12-14 |
| AU4174885A (en) | 1985-11-14 |
| DE3587961D1 (en) | 1995-01-26 |
| AU578682B2 (en) | 1988-11-03 |
| EP0160993A3 (en) | 1988-05-04 |
| ATE115818T1 (en) | 1994-12-15 |
| DE3417233A1 (en) | 1985-11-14 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry | ||
| MKEX | Expiry |
Effective date: 20051206 |