WO1999012275A1 - Commande adaptative de la puissance d'un sous-canal pilote - Google Patents

Commande adaptative de la puissance d'un sous-canal pilote Download PDF

Info

Publication number
WO1999012275A1
WO1999012275A1 PCT/US1998/017911 US9817911W WO9912275A1 WO 1999012275 A1 WO1999012275 A1 WO 1999012275A1 US 9817911 W US9817911 W US 9817911W WO 9912275 A1 WO9912275 A1 WO 9912275A1
Authority
WO
WIPO (PCT)
Prior art keywords
pilot
channel
remote unit
transmitting
power level
Prior art date
Application number
PCT/US1998/017911
Other languages
English (en)
Inventor
Michael D. Kotzin
Kamyar Rohani
Original Assignee
Motorola Inc.
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 Motorola Inc. filed Critical Motorola Inc.
Publication of WO1999012275A1 publication Critical patent/WO1999012275A1/fr

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
    • H04W52/30—TPC using constraints in the total amount of available transmission power
    • H04W52/32—TPC of broadcast or control channels
    • H04W52/322—Power control of broadcast channels
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S11/00—Systems for determining distance or velocity not using reflection or reradiation
    • G01S11/02—Systems for determining distance or velocity not using reflection or reradiation using radio waves
    • G01S11/06—Systems for determining distance or velocity not using reflection or reradiation using radio waves using intensity measurements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69—Spread spectrum techniques
    • H04B1/707—Spread spectrum techniques using direct sequence modulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/24—Radio transmission systems, i.e. using radiation field for communication between two or more posts
    • H04B7/26—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
    • H04B7/2628—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile using code-division multiple access [CDMA] or spread spectrum multiple access [SSMA]
    • 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
    • H04W52/30—TPC using constraints in the total amount of available transmission power
    • H04W52/32—TPC of broadcast or control channels
    • H04W52/325—Power control of control or pilot channels
    • 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
    • H04W52/38—TPC being performed in particular situations
    • H04W52/48—TPC being performed in particular situations during retransmission after error or non-acknowledgment

Definitions

  • the present invention relates generally to cellular communication systems and, in particular, to adaptive power control of a pilot sub-channel in such a communication system.
  • Pilot assisted modulation is commonly used for cellular communication systems.
  • a pilot sub-channel is broadcast, providing timing and phase synchronization to aid in subsequent demodulation of a transmitted signal.
  • pilot assisted modulation schemes are utilized by cellular systems.
  • One such pilot assisted modulation scheme is a Reference Coherent type transmission as described in US Pat. No. 5,329,547, METHOD AND APPARATUS FOR COHERENT COMMUNICATION IN A SPREAD-SPECTRUM COMMUNICATION SYSTEM, by Ling, and incorporated by reference herein.
  • Ling in a Code Division Multiple Access (CDMA) communication system, reference symbols are interspersed among the interleaved data symbols. For example, as described by Ling, a binary "1" is inserted after every three consecutive interleaved data symbols, and utilized by a receiver to help in channel estimation for coherent detection.
  • CDMA Code Division Multiple Access
  • Wideband 95 Another type of pilot assisted modulation occurs as proposed for utilization in the next generation CDMA communication system currently being developed, more commonly referred to as Wideband cdmaOne, or Wideband 95.
  • All remote unit and base station traffic channel transmissions have an associated pilot channel which utilizes a separate spreading code.
  • Wideband 95 systems utilize multiple pilot channels, each associated with an individual traffic channel, to aid in demodulation.
  • pilot assisted modulation schemes A problem exists with the above-mentioned pilot assisted modulation schemes in that the amount of pilot power is kept constant relative to the traffic channel power. In other words, a fixed number of pilot symbols are inserted, or the power of the pilot sub-channel is kept at a constant level relative to the traffic channel power. Because of this, unnecessary interference is generated by transmission of pilot channels at an unnecessarily high power level. Therefore a need exists for adaptive power control of a pilot sub-channel that reduces system interference.
  • FIG. 1 is a block diagram of a base station for transmitting a pilot channel in accordance with the preferred embodiment of the present invention.
  • FIG. 2 is a block diagram of a pilot channel transmitter in accordance with the preferred embodiment of the present invention.
  • FIG. 3 is a block diagram of a speed computer of FIG. 2 in accordance with the preferred embodiment of the present invention.
  • FIG. 4 is a block diagram of a traffic channel transmitter for transmitting a pilot channel in accordance with an alternate embodiment of the present invention.
  • FIG. 5 is a flow chart showing operation of the base station of FIG. 1 in accordance with the preferred embodiment of the present invention.
  • FIG. 6 is a block diagram of a base station for transmitting a pilot channel in accordance with an alternate embodiment of the present invention. Detailed Description of the Drawings
  • a base station utilizes traffic and pilot channels for both forward and reverse transmission. Traffic channel and pilot channel transmission from the base station as follows: During time periods where the remote unit is actively communicating to the base station utilizing a traffic channel, the remote unit is actively monitoring the pilot channel for utilization in coherent demodulation of traffic channel data. In addition, the base station actively monitors the speed of the remote unit. The base station determines an appropriate transmit power based on system conditions, and optimally adjusts pilot channel transmit power based on the system conditions. In particular, pilot channel transmit power is adjusted independent of traffic channel transmit power, and is based on remote unit speed.
  • the present invention encompasses providing timing and phase synchronization in a communication system where pilot sub-channels are broadcast to aid in subsequent demodulation of a transmitted signal.
  • a first pilot sub-channel is transmitted at a first pilot power level for utilization by a first remote unit and a first traffic channel is transmitted at a first traffic channel power level for utilization by the first remote unit.
  • a second pilot sub-channel is transmitted for utilization by a second remote unit, at a second pilot power level and a speed is determined for the first remote unit.
  • the first pilot sub-channel is transmitted at a third pilot power level while continuing to broadcast the first traffic channel at the first traffic channel power level, wherein the step of broadcasting at the third pilot power level is based on the determination of the speed of the first remote unit.
  • Another embodiment of the present invention encompasses transmitting a first pilot sub-channel at a first pilot power level for utilization by a first remote unit and transmitting a first traffic channel at a first traffic channel power level for utilization by the first remote unit. Additionally a second pilot sub-channel is transmitted for utilization by a second remote unit, at a second pilot power level. Next, a characteristic of the first remote unit is determined and the first pilot sub-channel is transmitted at a third pilot power level while continuing to broadcast the first traffic channel at the first traffic channel power level, where the step of broadcasting at the third pilot power level is based on the determined characteristic of the first remote unit.
  • a final embodiment of the present invention encompasses an apparatus for adaptive power control of a pilot sub-channel comprising a first transmitter for transmitting a first traffic channel at a first traffic channel power level for utilization by a first remote unit, a second transmitter coupled to the first transmitter for transmitting a first pilot sub-channel for utilization by a second remote unit, at a first pilot power level, circuitry for determining a characteristic of the first remote unit; and a third transmitter for transmitting a second pilot sub-channel at a second pilot power level for utilization by the first remote unit, the third transmitter additionally transmitting the first pilot sub-channel at a third pilot power level, where the step of broadcasting at the third pilot power level is based on the determined characteristic of the first remote unit.
  • FIG. 1 is a block diagram of a base station for transmitting a pilot channel in accordance with the preferred embodiment of the present invention.
  • the preferred embodiment of the present invention utilizes multiple pilot channels, each associated with an individual traffic channel to help aid in demodulation.
  • Base station 100 comprises base station controller 101, multiple traffic channel transmitters 103, multiple pilot channel transmitters 105, summer 111, and modulator 115. As shown, base station 100 is communicating to remote unit 113 via downlink communication signal 117, and remote unit 113 is communicating to base station 100 via uplink communication signal 119.
  • communication to remote unit 113 takes place utilizing both the pilot channel circuitry 105 and traffic channel circuitry 103.
  • base station 100 utilizes two classes of channels for both forward and reverse transmission.
  • the traffic channels are similar to existing CDMA traffic channels and are used for voice and signaling.
  • CDMA traffic channels are described in detail in IS-95A, which is incorporated by reference herein. As described in IS- 95A, the transmission rate of this channel may vary dynamically.
  • soft hand-off (simultaneous communication utilizing more than one traffic channel circuit 103) is supported utilizing traffic channel circuitry 103.
  • the pilot channels are utilized for assisting remote unit 113 in coherent demodulation and continuously broadcast a known pattern of l's or 0's.
  • Traffic channel and pilot channel transmission from base station 100 occurs as follows: During time periods where remote unit 113 is actively communicating to base station 100 utilizing a traffic channel, remote unit 113 is actively monitoring the pilot channel for utilization in coherent demodulation of traffic channel data. In addition, base station 100 actively monitors the speed of remote unit 113. Base station 100 determines an appropriate transmit power based on system conditions, and optimally adjusts pilot channel transmit power based on the system conditions.
  • pilot channel transmit power is adjusted independent of traffic channel transmit power, and is based on remote unit speed (however in an alternate embodiment of the present invention, pilot channel transmit power is adjusted based on feedback from remote unit 113, e.g., detection of pilot bits and adjustment of pilot power to achieve a constant target bit-error-rate).
  • pilot channel power is varied relative to the traffic channel power reducing unnecessary interference.
  • FIG. 2 is a block diagram of a pilot channel transmitter 105 in accordance with the preferred embodiment of the present invention.
  • Transmitter 105 includes convolutional encoder 212, interleave! 216, orthogonal encoder 220, modulator 252, upconverter 256, pilot channel gain computer (PGC) 201, speed computer 203, and antenna 258.
  • signal 210 is received by convolutional encoder 212 at a particular bit rate (e.g., 9.6 kbit/second).
  • Convolutional encoder 212 encodes input data bits 210 into data symbols at a fixed encoding rate with an encoding algorithm which facilitates subsequent maximum likelihood decoding of the data symbols into data bits (e.g. convolutional or block coding algorithms).
  • convolutional encoder 212 encodes input data bits 210 (received at a rate of 9.6 kbit/second) at a fixed encoding rate of one data bit to two data symbols (i.e., rate 1/3) such that convolutional encoder 212 outputs data symbols 214 at a 28.8 ksymbol/second rate.
  • Data symbols 214 are then input into interleaver 216.
  • Interleaver 216 interleaves the input data symbols 214 at the symbol level.
  • data symbols 214 are individually input into a matrix which defines a predetermined size block of data symbols 214.
  • Data symbols 214 are input into locations within a matrix so that the matrix is filled in a column by column manner.
  • Data symbols 214 are individually output from locations within the matrix so that the matrix is emptied in a row by row manner.
  • the matrix is a square matrix having a number of rows equal to the number of columns, however, other matrix forms can be chosen to increase the output interleaving distance between the consecutively input non- interleaved data symbols.
  • Interleaved data symbols 218 are output by interleaver 216 at the same data symbol rate that they were input (e.g., 28.8 ksymbol/second).
  • the predetermined size of the block of data symbols defined by the matrix is derived from the maximum number of data symbols which can be transmitted at a predetermined symbol rate within a predetermined length transmission block. For example, if the predetermined length of the transmission block is 20 milliseconds, then the predetermined size of the block of data symbols is 28.8 ksymbol/second times 20 milliseconds which equals 576 data symbols which defines a 18 by 32 matrix.
  • Interleaved data symbols 218 are input to orthogonal encoder
  • Orthogonal encoder 220 modulo 2 adds an orthogonal code (e.g., a 256-ary Walsh code) to each interleaved and scrambled data symbol 218.
  • an orthogonal code e.g., a 256-ary Walsh code
  • interleaved and scrambled data symbols 218 are each replaced by a 256 symbol orthogonal code or its inverse.
  • These 256 orthogonal codes preferably correspond to Walsh codes from a 256 by 256 Hadamard matrix wherein a Walsh code is a single row or column of the matrix.
  • Orthogonal encoder 220 repetitively outputs a Walsh code or its inverse 222 which corresponds to input data symbol 218 at a fixed symbol rate (e.g., 28.8 ksymbol/second).
  • PGC 201 updates pilot channel gain value Gpch 211 to minimize forward link interference while preserving adequate voice channel quality.
  • PGC 201 computes pilot channel gain estimate (Gpch 211) as a function of remote unit speed (supplied by speed computer) however in an alternate embodiment of the present invention Gpch 211 is calculated based on a requested power command received from remote unit 113. In particular, during low- speed, or stationary operation, pilot channel power is minimized.
  • remote unit speed is calculated as described in US Pat. No. (Application Serial No. 08/672,703) METHOD AND APPARATUS FOR POWER CONTROL IN A COMMUNICATION SYSTEM by Love et al.
  • Gpch 211 is then output to multiplier 240, which multiplies Walsh code's 222 amplitude by gain value Gpch 211, resulting in a sequence of weighted Walsh codes 242.
  • Sequence of weighted Walsh codes 242 is prepared for transmission over a communication channel by modulator 252.
  • the spreading code is a user specific sequence of symbols or unique user code which is output at a fixed chip rate (e.g., 3.6864 Mchip/ second).
  • the user code spread encoded chips are scrambled by a pair of short pseudorandom codes (i.e. short when compared to the long code) to generate an I-channel and Q-channel code spread sequence 226.
  • the I- channel and Q-channel code spread sequences 226 are used to bi-phase modulate a quadrature pair of sinusoids by driving the power level controls of the pair of sinusoids.
  • the sinusoids output signals are summed, bandpass filtered, translated to an RF frequency, amplified, filtered via upconverter 256 and radiated by antenna 258 within a 5 MHz bandwidth to complete transmission of channel data bits 210.
  • an estimation of a remote unit's speed can be determined from estimating the bandwidth of the faded signal.
  • a classic fading model is used in which the mobile is driving through an infinite field of minute scatterers which results in a U-shaped power spectrum, S(f). Assuming a vertically polarized electric field:
  • So is a constant giving the received power density within a small neighborhood of the transmit carrier frequency and / is the independent frequency variable.
  • the mobile speed may be estimated by finding the second central moment (variance) of the observed power spectrum, and the frequency offset between transmitter and receiver may be obtained by estimating the first moment (mean). For example, a speed estimate is obtained by measuring the standard deviation of the remote unit's observed power spectrum.
  • the remote unit's power spectrum is approximated by carrying out the following steps:
  • FIG. 3 is a block diagram of speed computer 203 of FIG. 2.
  • Speed computer 203 comprises RF front end 301, despreader 303, Data Selector 303, and discrete Fourier transformer (DFT) 307. Operation of speed computer 203 occurs as follows: A mixed, downconverted signal emerging from RF front end 301 enters despreader 303 where the incoming signal is despread. Pilot symbols emerge from despreader 303 and enter data selector 305 where pilot symbols are passed to DFT 307.
  • the DFT design parameters are:
  • a power control bit stream is utilized for calculating the remote unit's speed.
  • the power control bit stream exhibits periods of a regular up /down pattern that corresponds to channel coherence time. When neither signal is faded the pattern is similar to 11111000001111100000.'
  • an indication of velocity can be obtained by searching for discrete components in a frequency transform of the power control bit stream. If it is determined that much of the energy is located at a few predetermined frequency groups, the remote unit's speed is low, otherwise the remote unit's speed is high. The following steps are taken in the alternate embodiment:
  • FIG. 4 is a block diagram of a traffic channel transmitter 103 for transmitting a pilot channel in accordance with an alternate embodiment of the present invention.
  • pilot transmission occurs by inserting reference symbols with the interleaved traffic-channel data symbols.
  • Transmitter 103 includes convolutional encoder 412, interleaver 417, orthogonal encoder 420, modulator 452, upconverter 456, pilot symbol inserter 450, and gain computer 401.
  • signal 410 (traffic channel data), is output by a voice encoder (vocoder) and is received by convolutional encoder 412 at a particular transmission rate (e.g., 9.6 kbit/second).
  • Input traffic channel data bits 410 typically include voice converted to data by a vocoder, pure data, or a combination of the two types of data, and is output at a particular data rate (i.e., full rate, 1/2 rate, 1/4 rate, 1/8 rate . . . etc.).
  • Convolutional encoder 412 determines the transmission rate and encodes input data bits 410 into data symbols at a fixed encoding rate with an encoding algorithm which facilitates subsequent maximum likelihood decoding of the data symbols into data bits (e.g.
  • convolutional encoder 412 encodes input data bits 410 (received at a rate of 9.6 kbit/second) at a fixed encoding rate of one data bit to three data symbols (i.e., rate 1/3) such that convolutional encoder 412 outputs data symbols 414 at a 28.8 ksymbol/second rate.
  • Data symbols 414 are then input into interleaver 417.
  • Interleaver 417 interleaves the data symbols 414 at the symbol level.
  • data symbols 414 are individually input into locations within a matrix so that the matrix is filled in a column by column manner.
  • Data symbols 414 are individually output from locations within the matrix so that the matrix is emptied in a row by row manner.
  • the matrix is a square matrix having a number of rows equal to the number of columns; however, other matrix forms can be chosen to increase the output interleaving distance between the consecutively input non-interleaved data symbols.
  • Interleaved data symbols 418 are output by interleaver 417 at the same data symbol rate that they were input (e.g., 28.8 ksymbol/second).
  • the predetermined size of the block of data symbols defined by the matrix is derived from the maximum number of data symbols which can be transmitted at a predetermined symbol rate within a predetermined length transmission block.
  • Pilot symbols are inserted (punctured) by pilot symbol inserter 450 into the interleaved data symbol stream.
  • a binary "1" is inserted in every Nth symbol slot.
  • N is kept constant and the magnitude of the inserted reference symbols are varied based on system conditions.
  • the magnitude of the reference symbols are kept constant with respect to the magnitude of traffic channel symbols, however, the value of N is varied based on system conditions.
  • the receiver utilizes the pilot symbols (reference symbols) to help in channel estimation for coherent detection.
  • gain computer 401 receives a pilot channel power request (either a power-up or a power-down request) from remote unit 113, and varies the pilot channel gain value (Gpch 403) accordingly.
  • Gpch 403 varies the pilot channel gain value
  • gain computer 401 responding to a pilot channel power request from remote unit 113, adjusts Gpch 403 accordingly.
  • Each pilot symbol is multiplied by Gpch 403 prior to symbol insertion.
  • Gpch is kept at a constant value, and the frequency of pilot symbol insertions (N) is varied based on the pilot channel power request from remote unit 113.
  • pilot symbols are inserted every Nth symbol slot, where N is dependent on a pilot channel power requested by remote unit 113.
  • N is set equal to 4, and is then increased by a factor of two until an increase in pilot channel power is requested, at which point N is decreased by a factor of two.
  • Interleaved data symbols 418 (having pilot symbols inserted) are input to orthogonal encoder 420.
  • M-ary modulates the interleaved data symbols 418.
  • each sequence of six interleaved data symbols 418 are replaced by a 64 symbol orthogonal code.
  • These 64 orthogonal codes preferably correspond to Walsh codes from a 64 by 64 Hadamard matrix wherein a Walsh code is a single row or column of the matrix.
  • Gain computer 401 updates traffic channel gain values Gtch 444 based upon power control commands received from remote unit 113, however, in an alternate embodiment of the present invention, Gtch is adjusted based on remote unit 113 speed as discussed above in reference to FIG. 2. In the alternate embodiment of the present invention, Gtch is regulated independent of traffic channel gain Gpch. Gtch 444 is then output to multiplier 440, which multiplies Walsh code's 422 amplitude by gain value Gtch 444 resulting in a sequence of amplitude weighted and polarity modulated Walsh codes 442. A sequence of amplitude weighted and polarity modulated Walsh codes 442 is prepared for transmission over a communication channel by modulator 452.
  • FIG. 5 is a flow chart showing operation of the base station of
  • FIG. 1 in accordance with the preferred embodiment of the present invention.
  • pilot channel power is varied with respect to traffic channel power based on a speed of remote unit 113.
  • the logic flow begins at step 501 where remote unit 113 requests that a traffic channel be assigned to remote unit 113.
  • base station 100 assigns remote unit 113 a traffic channel
  • a pilot channel is assigned to remote unit 113.
  • a separate pilot channel is assigned for each traffic channel assigned, and is initially set to a maximum level of 25% of the traffic channel power. It should be noted that although description of the preferred embodiment describes communication with remote unit 113 utilizing a single traffic channel and pilot channel, simultaneous communication with multiple remote units can take place utilizing multiple traffic and pilot channels each transmitted at separate power levels.
  • pilot channel transmitter 105 determines remote unit 113 speed, and at step 520, determines if remote unit 113 speed is greater than a threshold (10 Mph). If at step 520 it is determined that remote unit 113 speed is greater than 10 Mph, then the logic flow continues to step 530, otherwise the logic flow continues to step 525 where pilot channel power is set to a minimum level of 5% of traffic channel power, and the logic flow continues to step 530.
  • base station controller 101 determines if the traffic channel has been dropped, and if not the logic flow returns to step 515, otherwise the logic flow continues to step 535 where the traffic channel is dropped, and then to step 540 where the paging channel is dropped.
  • remote unit 113 actively monitors the pilot channel power and requests base station 100 to increase or decrease pilot channel power.
  • the logic flow begins at step 601 where remote unit 113 requests that a traffic channel be assigned to remote unit 113.
  • base station 100 assigns remote unit 113 a traffic channel
  • a pilot channel is assigned to remote unit 113.
  • pilot symbols are inserted (punctured) by pilot symbol inserter 450 into the interleaved data symbol stream. In particular, a binary "1" is inserted in every Nth symbol slot.
  • the pilot channel is initially set to a maximum level.
  • setting the pilot channel power can occur in the alternate embodiment in one of two ways.
  • the value of N can be maintained and the pilot symbol power varied with respect to traffic channel symbols
  • the frequency of pilot channel reference symbols (N) can be varied.
  • the value of N is kept at 4 and the pilot symbol power is set to 100% of traffic channel power.
  • the value of N is set originally to 4 and the pilot symbol power (gain) is set equal to the traffic channel symbol power.
  • base station controller 101 determines if a system condition exists that requires an increase or decrease in pilot channel power.
  • the system condition is equivalent to a request by remote unit 113 that an increase or decrease in pilot channel power level occur, however in an alternate embodiment of the present invention, the system condition may alternatively be remote unit 113 speed, system interference level, or multi-path conditions. If, at step 615 base station controller 101 determines that a system condition does not exist that requires an increase or decrease in pilot channel power, the logic flow returns to step 615, otherwise the logic flow continues to step 620.
  • base station controller 101 determines if the system condition requires that an increase in pilot channel power occur, and if so the logic flow continues to step 630.
  • base station controller 101 instructs traffic channel transmitter 105 to increase pilot channel power.
  • one of two methods are used to increase pilot channel power.
  • the first embodiment of the present invention keeps N constant and increase only the pilot channel symbol power level, while the traffic channel power level remains constant.
  • pilot channel power is increased 3 dB.
  • pilot channel amplitude is kept constant, but insertion frequency (N) is increased.
  • N is increased by a factor of two. The logic flow continues to step 635.
  • step 620 base station controller 101 determines that the system condition does not require an increase in pilot channel power, then the logic flow continues to step 625 where pilot channel transmit power is decreased.
  • the first embodiment of the present invention keeps N constant and decreases only the pilot channel symbol power level, while the traffic channel power level remains constant.
  • pilot channel power is decreased 3 dB.
  • pilot channel amplitude is kept constant, but puncturing frequency (N) is decreased.
  • N is decreased by a factor of two.
  • step 635 it is determined if the call has been dropped. If at step 635 it has been determined that the call has not been dropped, the logic flow returns to step 615 otherwise the logic flow continues to step 640 where the traffic and pilot channels are dropped.
  • both the frequency of pilot channel puncturing and the pilot channel symbol amplitude can be varied simultaneously.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

Il est possible de communiquer avec un système de télécommunications en utilisant à la fois des circuits de canaux pilotes (105) et des circuits de canaux de trafic. En particulier une station de base (100) utilise lesdits canaux pour des transmissions aller et des transmissions retour. Les transmissions utilisant les canaux pilotes et les canaux de trafic se déroulent comme suit: pendant les périodes où l'unité distante (113) communique activement avec la station de base (100) sur un canal de trafic, l'unité distante (113) surveille activement le canal pilote en ce qui concerne la démodulation cohérente des données de trafic. De plus, la station de base (100) surveille activement la vitesse de l'unité distante (113) et détermine la puissance de transmission adaptée aux conditions du système. En particulier, la puissance de transmission du canal pilote est réglée indépendamment de la puissance de transmission du canal de trafic en fonction de la vitesse de l'unité distante.
PCT/US1998/017911 1997-09-02 1998-08-28 Commande adaptative de la puissance d'un sous-canal pilote WO1999012275A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US92206697A 1997-09-02 1997-09-02
US08/922,066 1997-09-02

Publications (1)

Publication Number Publication Date
WO1999012275A1 true WO1999012275A1 (fr) 1999-03-11

Family

ID=25446452

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1998/017911 WO1999012275A1 (fr) 1997-09-02 1998-08-28 Commande adaptative de la puissance d'un sous-canal pilote

Country Status (1)

Country Link
WO (1) WO1999012275A1 (fr)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20010035820A (ko) * 1999-10-04 2001-05-07 조정남 통신 시스템에서의 가변트래픽 상황을 위한 코드분할다중접속 신호 발생 장치
WO2001041335A1 (fr) * 1999-11-22 2001-06-07 Telefonaktiebolaget Lm Ericsson (Publ) Estimation de vitesse relative a l'aide de commandes de puissance d'emission de signaux
EP1168655A2 (fr) * 2000-06-14 2002-01-02 Nec Corporation Procédé de commande de puissance dans un système de communication radio AMDC
WO2002005578A1 (fr) 2000-07-12 2002-01-17 Symbol Technologies, Inc. Procede et appareil de commande de puissance variable dans des systemes de communication sans fil
WO2002019554A1 (fr) * 2000-08-30 2002-03-07 Roke Manor Research Limited Système de communication
WO2002027966A2 (fr) * 2000-09-25 2002-04-04 Motorola, Inc. Procede et appareil de regulation de la puissance pilote dans un systeme a acces multiple par repartition de code
EP1198938A1 (fr) * 2000-05-22 2002-04-24 Motorola, Inc. Recepteur multiniveau a modulation d'amplitude en quadrature resistant aux evanouissements des signaux
WO2002058255A2 (fr) * 2001-01-08 2002-07-25 Ericsson Inc. Systeme cdma utilisant des codes quasi-orthogonaux
WO2003021811A1 (fr) * 2001-08-31 2003-03-13 Motorola, Inc. Procede et appareil de regulation de la puissance durant un appel de groupe d'expedition
EP1575186A1 (fr) * 2004-03-11 2005-09-14 Lucent Technologies Inc. Méthode et système de commande de la puissance montante afin de maintenir le taux d'erreur désiré sur les trames dans un systeme de communications sans fil
EP1359784B1 (fr) * 2002-05-03 2007-06-20 TeliaSonera Finland Oyj Prevention de surcharge
GB2464259A (en) * 2008-09-30 2010-04-14 Ip Access Ltd Method of setting a transmit power level
CN1672342B (zh) * 2002-07-31 2010-04-28 摩托罗拉公司 导频信息增益控制方法和设备
DE112006002532B4 (de) * 2005-09-26 2017-09-21 Intel Corporation Mehrträger-Sender für Mehrfach-Eingabe-Mehrfach-Ausgabe-Kommunikationssysteme und Verfahren zum Punkturieren von Bits für Pilottöne
CN113315733A (zh) * 2021-07-13 2021-08-27 中国人民解放军国防科技大学 一种时频同步方法、通信系统及存储介质
CN114513436A (zh) * 2022-01-05 2022-05-17 浙江科睿微电子技术有限公司 Sdio设备传输速率的检测方法、系统及存储介质

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5559789A (en) * 1994-01-31 1996-09-24 Matsushita Electric Industrial Co., Ltd. CDMA/TDD Radio Communication System
US5734646A (en) * 1995-10-05 1998-03-31 Lucent Technologies Inc. Code division multiple access system providing load and interference based demand assignment service to users
US5771461A (en) * 1996-06-28 1998-06-23 Motorola, Inc. Method and apparatus for power control of a first channel based on a signal quality of a second channel

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5559789A (en) * 1994-01-31 1996-09-24 Matsushita Electric Industrial Co., Ltd. CDMA/TDD Radio Communication System
US5734646A (en) * 1995-10-05 1998-03-31 Lucent Technologies Inc. Code division multiple access system providing load and interference based demand assignment service to users
US5771461A (en) * 1996-06-28 1998-06-23 Motorola, Inc. Method and apparatus for power control of a first channel based on a signal quality of a second channel

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20010035820A (ko) * 1999-10-04 2001-05-07 조정남 통신 시스템에서의 가변트래픽 상황을 위한 코드분할다중접속 신호 발생 장치
WO2001041335A1 (fr) * 1999-11-22 2001-06-07 Telefonaktiebolaget Lm Ericsson (Publ) Estimation de vitesse relative a l'aide de commandes de puissance d'emission de signaux
EP1198938A4 (fr) * 2000-05-22 2005-04-13 Motorola Inc Recepteur multiniveau a modulation d'amplitude en quadrature resistant aux evanouissements des signaux
EP1198938A1 (fr) * 2000-05-22 2002-04-24 Motorola, Inc. Recepteur multiniveau a modulation d'amplitude en quadrature resistant aux evanouissements des signaux
EP1168655A2 (fr) * 2000-06-14 2002-01-02 Nec Corporation Procédé de commande de puissance dans un système de communication radio AMDC
EP1168655A3 (fr) * 2000-06-14 2009-06-17 Nec Corporation Procédé de commande de puissance dans un système de communication radio AMDC
WO2002005578A1 (fr) 2000-07-12 2002-01-17 Symbol Technologies, Inc. Procede et appareil de commande de puissance variable dans des systemes de communication sans fil
EP1300029A4 (fr) * 2000-07-12 2010-08-25 Symbol Technologies Inc Procede et appareil de commande de puissance variable dans des systemes de communication sans fil
EP1300029A1 (fr) * 2000-07-12 2003-04-09 Symbol Technologies, Inc. Procede et appareil de commande de puissance variable dans des systemes de communication sans fil
WO2002019554A1 (fr) * 2000-08-30 2002-03-07 Roke Manor Research Limited Système de communication
WO2002027966A2 (fr) * 2000-09-25 2002-04-04 Motorola, Inc. Procede et appareil de regulation de la puissance pilote dans un systeme a acces multiple par repartition de code
WO2002027966A3 (fr) * 2000-09-25 2002-08-01 Motorola Inc Procede et appareil de regulation de la puissance pilote dans un systeme a acces multiple par repartition de code
WO2002058255A2 (fr) * 2001-01-08 2002-07-25 Ericsson Inc. Systeme cdma utilisant des codes quasi-orthogonaux
US7133353B2 (en) 2001-01-08 2006-11-07 Telefonaktiebolaget Lm Ericsson (Publ) CDMA system using quasi-orthogonal codes
WO2002058255A3 (fr) * 2001-01-08 2002-11-28 Ericsson Inc Systeme cdma utilisant des codes quasi-orthogonaux
WO2003021811A1 (fr) * 2001-08-31 2003-03-13 Motorola, Inc. Procede et appareil de regulation de la puissance durant un appel de groupe d'expedition
US6748231B2 (en) 2001-08-31 2004-06-08 Motorola, Inc. Method and apparatus for controlling power during a dispatch group call
EP1359784B1 (fr) * 2002-05-03 2007-06-20 TeliaSonera Finland Oyj Prevention de surcharge
CN1672342B (zh) * 2002-07-31 2010-04-28 摩托罗拉公司 导频信息增益控制方法和设备
EP1575186A1 (fr) * 2004-03-11 2005-09-14 Lucent Technologies Inc. Méthode et système de commande de la puissance montante afin de maintenir le taux d'erreur désiré sur les trames dans un systeme de communications sans fil
US7266723B2 (en) 2004-03-11 2007-09-04 Lucent Technologies Inc. Method and apparatus for controlling uplink power to maintain desired frame error rate in a wireless communications system
DE112006002532B4 (de) * 2005-09-26 2017-09-21 Intel Corporation Mehrträger-Sender für Mehrfach-Eingabe-Mehrfach-Ausgabe-Kommunikationssysteme und Verfahren zum Punkturieren von Bits für Pilottöne
GB2464259A (en) * 2008-09-30 2010-04-14 Ip Access Ltd Method of setting a transmit power level
US8666422B2 (en) 2008-09-30 2014-03-04 Ip.Access Limited Method and apparatus for setting a transmit power level
GB2464259B (en) * 2008-09-30 2011-04-27 Ip Access Ltd Method and apparatus for setting a transmit power level
CN113315733A (zh) * 2021-07-13 2021-08-27 中国人民解放军国防科技大学 一种时频同步方法、通信系统及存储介质
CN114513436A (zh) * 2022-01-05 2022-05-17 浙江科睿微电子技术有限公司 Sdio设备传输速率的检测方法、系统及存储介质
CN114513436B (zh) * 2022-01-05 2023-10-03 浙江科睿微电子技术有限公司 Sdio设备传输速率的检测方法、系统及存储介质

Similar Documents

Publication Publication Date Title
US9913271B2 (en) Qualifying available reverse link coding rates from access channel power setting
JP3957321B2 (ja) 通信システムにおける電力制御の方法および装置
EP1036437B1 (fr) Procedes et appareils permettant d'effectuer une commande de puissance ternaire dans un systeme de communication
US6600773B2 (en) Method for outer loop/weighted open loop power control apparatus employed by a base station
US6577668B2 (en) User equipment utilizing weighted open loop power control
US8948705B2 (en) Multiple-access hybrid OFDM-CDMA system
KR100234913B1 (ko) Cdma 통신 시스템의 전력 제어
US6233439B1 (en) Signal to noise estimation of forward link traffic channel for fast power control
EP1578029A2 (fr) Commande de puissance en boucle externe/boucle ouverte pondérée dans un système de communication duplex à répartition dans le temps
WO1999012275A1 (fr) Commande adaptative de la puissance d'un sous-canal pilote
CN1363147A (zh) 控制选通发送通信系统的方法和设备
US6654358B1 (en) Method for transmitting power control signal in mobile communication system
KR20030035040A (ko) 이동통신시스템의 핸드오프시 역방향 전력제어채널의전송제어를 위한 방법 및 장치
KR20030077908A (ko) 무선 통신시스템에서 이동 단말에 대한 전력제어 방법 및장치
KR20020039503A (ko) 음성 및 패킷 데이터 서비스를 위한 이동 통신시스템에서효율적인 패킷 데이터의 전송을 위한 송신전력 제어 장치및 방법

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): BR CA CN FI GB IL JP KR SE

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI 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
NENP Non-entry into the national phase

Ref country code: KR

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: CA