WO1995012927A1 - Procede d'emission de signaux radio et emetteur-recepteur armt - Google Patents

Procede d'emission de signaux radio et emetteur-recepteur armt Download PDF

Info

Publication number
WO1995012927A1
WO1995012927A1 PCT/FI1994/000493 FI9400493W WO9512927A1 WO 1995012927 A1 WO1995012927 A1 WO 1995012927A1 FI 9400493 W FI9400493 W FI 9400493W WO 9512927 A1 WO9512927 A1 WO 9512927A1
Authority
WO
WIPO (PCT)
Prior art keywords
transceiver
antenna
phase
signals
radio unit
Prior art date
Application number
PCT/FI1994/000493
Other languages
English (en)
Inventor
Eero Heikkinen
Juha SÄRKIOJA
Original Assignee
Nokia Telecommunications Oy
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nokia Telecommunications Oy filed Critical Nokia Telecommunications Oy
Priority to AU80628/94A priority Critical patent/AU8062894A/en
Publication of WO1995012927A1 publication Critical patent/WO1995012927A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
    • H04B7/0667—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of delayed versions of same signal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
    • H04B7/0682—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission using phase diversity (e.g. phase sweeping)

Definitions

  • This invention relates to a method for trans- mitting radio-frequency signals by a TDMA transceiver comprising means for transmitting a burst by two antenna means to active radio units located within the coverage area of the transceiver, the antenna means being arranged at a distance from each other, wherein a burst to be transmitted is applied to the first and the second antenna means in such a way that there occurs a phase difference between signals transmitted by the first and the second antenna means.
  • the inven ⁇ tion also relates to a TDMA transceiver comprising means for transmitting a radio-frequency burst by two antenna means positioned at a distance from each other to active radio units located within the coverage area of the transceiver, the transceiver comprising a branching means for feeding a burst to be transmitted to a first and a second antenna branch, the first antenna branch comprising the first antenna means, and the second antenna branch comprising the second antenna means and a phase-shifting means for providing a phase difference between bursts transmitted by the first and the second antenna means.
  • the invention is concerned particularly with a base station transceiver in a cellular radio system, which provides radio communication with active radio transmitters located within the coverage area of the base station.
  • burst refers to a group of signals transmitted during one time slot in time division multiplexing, i.e. to a predetermined number of bits transmitted during a predetermined period of time.
  • the GSM system is one example of a cellular radio system divided into time slots on the TDMA (Time Division Multiple Access) principle, where signalling takes place in bursts.
  • TDMA Time Division Multiple Access
  • U.S. Patent 4,849,990 discloses a solution where the transmitter and receiver of a base station are duplicated and they process the signal in two separate branches, between which there is a desired delay dif ⁇ ference realized by delay means.
  • the solution aims to improve the reliability of a radio link interfered with multipath propagation when DSK, BPSK-RZ or other similar modulation is used.
  • one of the transmitting branches of the duplicated trans ⁇ mitter delays a baseband information signal by the delay means before modulation, whereby a significant delay difference occurs between signals transmitted by two separate antenna means as compared with the trans ⁇ mission delay of one information symbol.
  • U.S. Patent 4,849,990 comprises two separate high-frequency receivers, wherein a delay means provided in one of the receiving branches delays a signal to be received significantly as compared with the transmission delay of the information symbol, whereafter signals received from the different receivers are combined and the obtained signal having the original modulation is detected by the demodulator according to the pub ⁇ lication.
  • the delay difference has to be selected in accordance with the duration of the information symbol and the magnitude of the delay spread caused by multi-path propagation.
  • the specifications of the GSM system offer a few solutions attempting to improve the audibility within a radio cell, such as interleaving of signal groups in the time domain over several bursts and frequency hopping. If the audibility is to be improved by using these measures, it is necessary that the radio unit receiving signals from the base station moves, as these measures are of no use if the radio unit remains stationary at a field strength minimum.
  • Diversity reception is another solution applic ⁇ able in the GSM system for improving audibility of radio signals transmitted from a radio unit towards a base station.
  • the base station receives signals from a specific radio unit by means of two antennas positioned at a distance from each other. Due to reflections, signals transmitted from the radio unit have a greater strength at either one of the antennas.
  • the base station thus comprises measuring means enabling it to measure the signal levels of signals received by the different antennas. On the basis of the measurements, the base station selects the antenna to be used for receiving signals from the radio unit.
  • diversity reception cannot be utilized in the reception of signals from the base station to the radio unit, as it is almost impossible to fit two antennas in the radio unit due to its small size.
  • the object of the present invention is to solve the above-mentioned problems, and provide a method which allows the audibility of signals transmitted from a base station to a specific radio unit to be improved significantly, even though the radio unit remains stationary during transmission.
  • the invention also relates to a transceiver in which the method according to the invention can be applied.
  • the transceiver according to the invention is characterized in that the transceiver comprises means for controlling the phase-shifting means so as to maximize the signal level of signals received by a predetermined radio unit receiving signals from the transceiver.
  • the invention is based on the idea that when an outbound burst is transmitted by two antennas in such a way that there occurs a phase difference between the signals transmitted from the antennas, the obtained antenna pattern can be adjusted in a desired manner by varying the phase difference in such a way that the field strength minimums of the signal to be trans ⁇ mitted will not be located at a predetermined, pos ⁇ sibly stationary radio unit.
  • the antenna pattern can be modified by suitably varying the phase difference so that the field strength maximum will be located at a predetermined radio unit.
  • the invention utilizes the fact that the distance between the antennas is con ⁇ siderably greater than the wave length of the carrier of the signal to be transmitted.
  • the signal path of signals transmitted by the different antennas will vary greatly, which is of advantage to the invention, as the varying signal paths create a non-uniform radiation pattern with several maximums separated by narrow minimums.
  • the minimums occur in a direction where the carriers of the signals transmitted are in opposite phases.
  • the most important advantage of the method and the transceiver according to the invention is thus that they are capable of preventing a stationary or slowly moving radio unit from remaining at a field strength minimum, as in such cases the field strength minimum can be shifted by adjusting the phase difference between the signals transmitted by the antennas of the transceiver.
  • a first preferred embodiment of the solution according to the invention comprises a transceiver utilizing diversity reception, in which case a bearing for a specific radio unit can be calculated on the basis of a phase difference between signals obtained from the two receiving antennas of the transceiver.
  • the phase difference of the signals to be transmitted by the antennas is then adjusted so that the field strength maximum will be located in the direction where the concerned radio unit is located.
  • the phase difference of signals transmitted by the antennas is adjusted after the transmission of a burst until the signal level of signals received by a receiver unit receiving signals from the transmitter is at maximum.
  • the phase differ ⁇ ence is varied between bursts in small steps, e.g. at intervals of 5° until a desired signal level maximum is achieved.
  • the phase difference is thereafter main ⁇ tained constant until it is detected that the signal level is again decreasing, and the phase-difference adjustment is restarted.
  • Figure 1 shows an antenna pattern created by a transceiver according to the invention
  • Figure 2 is a block diagram illustrating a preferred embodiment of the transceiver according to the invention
  • FIG. 3 is a block diagram illustrating a second preferred embodiment of the transceiver accord- ing to the invention.
  • Figure 4 is a block diagram illustrating a third preferred embodiment of the transceiver according to the invention.
  • FIG 1 shows an antenna pattern created by a transceiver according to the invention.
  • the trans ⁇ DC shown in Figure 1 comprises two antennas 5 and 6, by means of which it transmits radios signals within its coverage area.
  • the antennas are positioned at a distance d from each other.
  • the distance d is substantially greater than the wave length of the carrier of the signal to be transmitted (e.g. 9 times greater).
  • the signal path of signals transmitted by the different antennas will thus vary greatly, which is advantageous as the varying signal paths create a non-uniform radiation pattern with several maximums.
  • the maximums of the radiation pattern are indicated by lines 14, the phase difference ⁇ between the signals transmitted by the antennas 5 and 6 being 0°.
  • the location of the maximums 14 depends on the distance between the antennas and the phase difference between the signals transmitted by the antennas 5 and 6. If the phase difference is altered, the maximums shift accordingly.
  • Broken lines 15 in Figure 1 show the maximums of the radiation pattern when the phase difference ⁇ is 180°.
  • FIG. 2 is a block diagram illustrating a preferred embodiment of the transceiver according to the invention. It shows the transmission side of a transceiver fitted in a GSM base station, the reception side being not shown.
  • the transceiver of Figure 2 comprises a branching means 1 which branches an outbound burst into the two antenna branches of the transceiver. In the first antenna branch, the burst is applied from the branching means 1 to the transmitter 2, the output of which is connected to the antenna 5. In the second antenna branch, the burst is applied from the branching means 1 to a variable phase-shifting means or delay means 3.
  • This phase- shifting means may be e.g. a variable electric or ferromagnetic phase shifter.
  • the output of the phase- shifting means 3 is connected to the input of the transmitter 4, from which the burst is forwarded to the second antenna 6. Due to the phase-shifting means 3, there will occur a phase difference between the signals transmitted by the antennas 5 and 6 positioned at a distance from each other.
  • the magnitude of the phase difference can be adjusted by the phase-shifting means 3 e.g. in such a way that the maximum of the created antenna pattern will be located at a pre- determined receiver or, alternatively, in such a way that the phase difference varies randomly between 0° and 180°.
  • the phase difference however, has to change sufficiently slowly so that it will not affect the modulation of the signal to be transmitted. According to the invention, this is avoided in such a way that the phase difference is kept constant during the transmission of a specific burst, whereafter it can be changed.
  • one possible altern- ative is to use e.g. the baseband section of the transceiver of the GSM base station as the branching means 1 and the phase-shifting means 3.
  • the same burst is transmitted from this section to the two trans ⁇ mitters 2 and 4 with a small delay between the trans- missions.
  • Figure 3 shows a block diagram illustrating a second preferred embodiment of the transceiver accord ⁇ ing to the invention. It shows a transceiver fitted in a GSM base station and comprising two antennas used for reception and two receivers for diversity recep ⁇ tion.
  • the transmission side of the transceiver shown in Figure 3 is similar to that described with refer ⁇ ence to Figure 2.
  • rotating means 7 and 8 are provided between the transmitters 2 and 4 and the antennas 5 and 6 in order that the antennas 5 and 6 could be used both for transmitting and receiving signals.
  • phase-shifting means 3 is then adjusted so that the field strength maximum of signals transmitted by the transmitters 2 and 4 is directed towards the radio transmitter from which signals are being received.
  • FIG. 4 is a block diagram illustrating a third preferred embodiment of the transceiver according to the invention.
  • the transceiver section of a GSM base station shown in Figure 4 corresponds to that de ⁇ scribed with reference to Figure 2 except that it comprises a single transmitter 2. Signals from this transmitter are branched in a branching means 1 having an output to which an antenna 5 is connected and an ⁇ other output to which a phase-shifting means 3 is connected.
  • the phase-shifting means 3 provide a desired phase shift between signals transmitted by the antennas 5 and 6, the output of the phase-shifting means 3 being connected to the antenna 6.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Radio Transmission System (AREA)

Abstract

Procédé de transmission de signaux radioélectriques à des unités actives de radiocommunication par l'intermédiaire d'un émetteur-récepteur AMRT comportant des dispositifs émettant une rafale à l'aide de deux antennes (5, 6), lesdites unités étant comprises dans la zone desservie par l'émetteur-récepteur, et les antennes (5, 6) étant situées à une certaine distance (d) l'une de l'autre. Dans le but d'améliorer, au niveau du récepteur, l'audibilité des signaux transmis par l'émetteur, on envoie la rafale à transmettre à la première antenne (5) puis, après un retard prédéterminé, à la seconde antenne (6), de manière à créer une différence de phase entre les signaux émis par les première et seconde antennes. On a également prévu une unité émettrice-réceptrice pour la mise en ÷uvre du procédé.
PCT/FI1994/000493 1993-11-04 1994-11-03 Procede d'emission de signaux radio et emetteur-recepteur armt WO1995012927A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU80628/94A AU8062894A (en) 1993-11-04 1994-11-03 A method for transmitting radio signals, and a tdma transceiver

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI934875 1993-11-04
FI934875A FI934875A (fi) 1993-11-04 1993-11-04 Menetelmä radiotaajuisten signaalien lähettämiseksi sekä TDMA-lähetinvastaanotin

Publications (1)

Publication Number Publication Date
WO1995012927A1 true WO1995012927A1 (fr) 1995-05-11

Family

ID=8538897

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI1994/000493 WO1995012927A1 (fr) 1993-11-04 1994-11-03 Procede d'emission de signaux radio et emetteur-recepteur armt

Country Status (3)

Country Link
AU (1) AU8062894A (fr)
FI (1) FI934875A (fr)
WO (1) WO1995012927A1 (fr)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0755130A2 (fr) * 1995-07-20 1997-01-22 Telia Ab Dispositif d'antenne
DE19546599A1 (de) * 1995-12-13 1997-06-19 Siemens Ag Sendeeinrichtung
GB2318027A (en) * 1996-10-04 1998-04-08 Plessey Semiconductors Ltd Mobile transceiver with space diversity transmission and reception
WO1998056122A1 (fr) * 1997-06-06 1998-12-10 Nokia Mobile Phones Limited Procede et appareil de regulation de diversite de temps en telephonie
EP0923203A2 (fr) * 1997-12-10 1999-06-16 Alcatel Dispositif pour la transmission d'une signal radio via un réseau d'antennes a une station mobile dans un système mobile radio
WO2002007341A2 (fr) * 2000-07-14 2002-01-24 Ip.Access Ltd. Systeme de radiotelecommunication cellulaire
US7149258B2 (en) 2001-11-28 2006-12-12 Telefonaktiebolaget L M Ericsson (Publ) Method and apparatus for estimation of phase offset between communication channels
EP1788722A1 (fr) * 2005-11-21 2007-05-23 Nortel Networks Limited Procédé de transmission et station de base correspondante
WO2007095328A3 (fr) * 2006-02-14 2007-11-29 Sibeam Couche physique hd d'un dispositif de communication sans fil

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3806937A (en) * 1972-04-24 1974-04-23 Esl Inc Automatic direction finding system utilizing digital techniques
SE440576B (sv) * 1978-04-28 1985-08-05 Kokusai Denshin Denwa Co Ltd Rumsbaserat diversitetssystem for ett tidmultiplexkommunikationssystem
WO1991004615A1 (fr) * 1989-09-12 1991-04-04 Telefonaktiebolaget Lm Ericsson Methode de diminution les risques de faible reception dans un systeme de radiocommunications multiplexe dans le temps
US5127025A (en) * 1989-05-02 1992-06-30 Nec Corporation Space diversity tdma receiver

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3806937A (en) * 1972-04-24 1974-04-23 Esl Inc Automatic direction finding system utilizing digital techniques
SE440576B (sv) * 1978-04-28 1985-08-05 Kokusai Denshin Denwa Co Ltd Rumsbaserat diversitetssystem for ett tidmultiplexkommunikationssystem
US5127025A (en) * 1989-05-02 1992-06-30 Nec Corporation Space diversity tdma receiver
WO1991004615A1 (fr) * 1989-09-12 1991-04-04 Telefonaktiebolaget Lm Ericsson Methode de diminution les risques de faible reception dans un systeme de radiocommunications multiplexe dans le temps

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN, Vol. 11, No. 83, E-489; & JP,A,61 237 502 (NEC CORP), 22 October 1986. *

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0755130A3 (fr) * 1995-07-20 1997-12-03 Telia Ab Dispositif d'antenne
EP0755130A2 (fr) * 1995-07-20 1997-01-22 Telia Ab Dispositif d'antenne
DE19546599A1 (de) * 1995-12-13 1997-06-19 Siemens Ag Sendeeinrichtung
DE19546599C2 (de) * 1995-12-13 1999-07-29 Siemens Ag Sendeeinrichtung
GB2318027A (en) * 1996-10-04 1998-04-08 Plessey Semiconductors Ltd Mobile transceiver with space diversity transmission and reception
US6463080B1 (en) 1997-06-06 2002-10-08 Nokia Mobile Phones Ltd. Method and apparatus for controlling time diversity in telephony
WO1998056122A1 (fr) * 1997-06-06 1998-12-10 Nokia Mobile Phones Limited Procede et appareil de regulation de diversite de temps en telephonie
EP0923203A2 (fr) * 1997-12-10 1999-06-16 Alcatel Dispositif pour la transmission d'une signal radio via un réseau d'antennes a une station mobile dans un système mobile radio
EP0923203A3 (fr) * 1997-12-10 2000-11-08 Alcatel Dispositif pour la transmission d'une signal radio via un réseau d'antennes a une station mobile dans un système mobile radio
WO2002007341A2 (fr) * 2000-07-14 2002-01-24 Ip.Access Ltd. Systeme de radiotelecommunication cellulaire
WO2002007341A3 (fr) * 2000-07-14 2002-05-30 Ip Access Ltd Systeme de radiotelecommunication cellulaire
US7149258B2 (en) 2001-11-28 2006-12-12 Telefonaktiebolaget L M Ericsson (Publ) Method and apparatus for estimation of phase offset between communication channels
EP1788722A1 (fr) * 2005-11-21 2007-05-23 Nortel Networks Limited Procédé de transmission et station de base correspondante
US7962177B2 (en) 2005-11-21 2011-06-14 Nortel Networks Limited Transmission method and related base station
WO2007095328A3 (fr) * 2006-02-14 2007-11-29 Sibeam Couche physique hd d'un dispositif de communication sans fil
US8014416B2 (en) 2006-02-14 2011-09-06 Sibeam, Inc. HD physical layer of a wireless communication device
EP2958258A1 (fr) * 2006-02-14 2015-12-23 Sibeam, Inc. Couche physique hd d'un dispositif de communication sans fil

Also Published As

Publication number Publication date
FI934875A0 (fi) 1993-11-04
FI934875A (fi) 1995-05-05
AU8062894A (en) 1995-05-23

Similar Documents

Publication Publication Date Title
US7346316B1 (en) Radio communication system, a transmitter and a receiver
JP2947157B2 (ja) 送信空間ダイバーシティ制御方法及び送信空間ダイバーシティ装置
EP0224586B1 (fr) Equipement de communication numerique
US6212405B1 (en) Extended range concentric cell base station
KR100697227B1 (ko) 파일럿신호 검출방법 및 수신기
WO1995026040A2 (fr) Procede de modulation par sauts de frequence et equipement de station de base
EP1003310A1 (fr) Dispositif d'etalonnage
AU6211398A (en) Doppler direction finder and method of location using doppler direction finder
WO1995012927A1 (fr) Procede d'emission de signaux radio et emetteur-recepteur armt
KR19990083110A (ko) 적응성 안테나용 지향성 제어 회로
US4156873A (en) Transponder for a moving vehicle tracking system
KR920702105A (ko) 시분할 다중 무선 통신시스템에서 바람직하지 못한 수신의 위험을 줄이는 방법
Marin et al. Monostatic FMCW radar architecture for multifunction full-duplex radios
US9647861B1 (en) Multiple antenna transmission of pulsed data communication messages with phase or time dithering for reduction of static interference nulls
GB2296625A (en) Anti-fading transmitter power control
JPH09181699A (ja) 移動中継装置
JPH0546128B2 (fr)
JPH10163937A (ja) アンテナ切り替え制御方式
JP2000183856A (ja) 複局送信システム
JP2001223623A (ja) デジタル無線通信システム
JPH07154299A (ja) 直接拡散通信妨害装置
JPH01288023A (ja) ミリ波構内無線通信方式
JPH08172423A (ja) アンテナダイバーシチ受信方式
JP2604093B2 (ja) アレイアンテナ指向性適応送受信装置
JP2879859B2 (ja) ホットスタンドバイ通信方式による多重無線装置

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU CN DE GB JP NO US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase