CN1291832A - Self adaptive power control in wide band code division multiplexing honeycomb system and operation method - Google Patents

Abstract

A wideband code division multiple access (WCDMA) system includes a base station(BS)and a mobile station(MS); a channel comprising a baseband signal having variable transmission rate and a guide channel coupled with the base station and the mobile station; a device responding to the baseband signal and use for predicating the attenuation of the future power on the channels; a device responding to the channel predicating device and used for notifying the transmitter and the receiver by the guide channel so as to reset the transmission rate according to the predicated power attenuation.

Description

Adaptive power control and method of operation in the wide band code division multiplexing honeycomb system

The present invention requires to be " Seamless Rate Change In Wideband CDMA Cellular System (WCDMA) " in the exercise question of application on October 26th, 1998, sequence number is 60/105,639, and be transferred to the interests of the applying date of assignee's of the present invention provisional application, and be incorporated herein, only for reference.

The sequence number of the application and application on October 7th, 1999 is 09/413,935, exercise question is " ADAPTIVE POWERR CONTROL BASED ON A RAKERECEIVER CONFIGURATION IN WIDEBAND CDMACELLULAR SYSTEMS (WCDMA) AND METHODS OFOPERATION's ", the assigned same assignee's of the present invention of giving application is correlated with, and is incorporated herein only for reference.

The present invention relates to communication system and method for operation thereof.Especially, the present invention relates to adaptive power management and method of operation in the wide band code division multiplexing honeycomb system (WCDMA).

In wireless communication system, the signal fadeout that is caused by multipath radio propagation has seriously reduced performance, and forces the demand to the high emission acc power.Because changes in channel characteristics is rapid, transmitter and receiver can not be configured to make it to work under the optimal performance level, therefore, they can not utilize whole potential of wireless system.Code division multiple access (CDMA) provides the capacity that increases, and this is because each user in this system has whole frequency band, therefore, does not have the waste to bandwidth that causes owing to channel spacing.Third generation wireless system provides several systems.Most popular system just under study for action is wideband CDMA (W-CDMA) system, in the document 90 of the IEEE VehicularTechnology Conference that delivers in May, 1999, it is illustrated in the article of " Channel Estimation for the W-CDMASystem, Performance and Robustness Analyses from a TerminalPerspective " by the exercise question that B.Lindof, C.Ostberg and H.Eriksson write.

The developer of the third generation wireless system of industry imagines the speech business clearly that can carry out crystal on radio telephone or hand-held PC, from the surfing on the net of Anywhere video conference, high-speed mobile and thousands of advanced person's applying right.In general, can improve transmission, sound and the video of the high-speed data of on mobile device, carrying out, simultaneously can increase battery life again, to the improvement of any this class of system concerning imagination with all be challenging exercise question improving.

In IEEE Transaction on VehicularTechnology the 47th volume No.4 that publishes in November, 1998, the 1134-1147 page or leaf, by T.Ue, S.Sampei, the exercise question that N.Morinaga and K.Hamaguchi write is the IEICE Transaction on Communication E80-B volume of " Symbol Rate andModulation Level-Controlled Adaptive Modulation/TDMA/TDDSystem for High-Bit-Rate Wireless Data Transmission " and in April, 1997 publication, No.4, the 581-583 page or leaf, by S.Abeta, the exercise question that S.Sampei and N.Morinaga write is in the document of " Adaptive Coding and Processing Gain Control with ChannelActivation for Multimedia DS/CDMA System ", expert advice use from the base station (BS) to the chip rate of the feedback transmission of the information of travelling carriage (MS), gain and code conversion scheme.In these suggestions, the quality of channel is by the signal-to-jamming ratio C/ (N to the short-term at BS receiver place ₀+ I ₀) calculate and determine that wherein C is a signal power; N ₀Be AWGN power, I ₀It is interference from other user.But, in broadband environment, owing to intersymbol interference (ISI) occurred, the signal noise ratio (SNR) that just is unsuitable for short-term is come the measured channel quality, as the IEEEVehicular Technology Conference that publishes in May, 1999, document 483, the _ page or leaf is illustrated in the document of " Upper-bound Performance of aWideband Burst-by-Burst Adaptive Modem " by the exercise question that C.H.Wong and L.Hanzo write.

Other prior art with improved performance relevant with the WCDMA system comprises:

The method and apparatus of the through-put power that is used for controlling variable rate communication system is disclosed in the people's such as E.Tiedemann, Jr. of on October 13rd, 1998 distribution the United States Patent (USP) 5,822,381 (Tiedemann).Disclosed method provides a kind of close-loop power controlling method.First distant station is by sending a power control signal that depends on speed to second telecommunication system, thereby controls the through-put power of second distant station.Owing to have only the second communication system to think that its transmission rate is a priori, thus must foundation received power control signal with and the knowledge of transmission rate and determine an operating process.

The apparatus and method of the final through-put power Y of the base station that is used for controlling the cellular communication system with several channels are disclosed in the people's such as L.A.Weaver, Jr that on February 3rd, 1998 delivered the United States Patent (USP) 5,715,526 (Weaver).The base station has transmitter power and follows the tracks of gain ' Y ' and radio-frequency emission power ' W '.This device comprises and is used to calculate desired power P _{K, a}-P _KfChannel Elements, described each power is all corresponding with a channel.This device also comprises the required power output Y that is used to produce the base station _dA radio receiving machine controller (BTSC), this controller comprises and is used for desired power is added together an adder.This device also comprises and is used for measuring ' Y ' to obtain a transmitting power detector of the transmitting power through measuring.This device also comprises a radio frequency interface card (RFIC) that is used for producing ' Y '.At last, this device comprises a gain unit, is used for handling ' Y ' and ' W ', to obtain final transmitting power ' Y '.

Disclose a kind of power control process in people's such as the C.E.Wheatley that publishes January 17 nineteen ninety-five, III the United States Patent (USP) 5,383,219 (Wheatley), it can allow mobile radiotelephone continuously the base station to be upgraded according to required power output.The base station with special speed to the travelling carriage transmit frame.If travelling carriage can correct received frame, and frame is correctly decoded, then travelling carriage is just set the power control bits and the next frame that will send the base station to.According to the error rate of received power control bits, the base station decision is to increase or reduce transmitting power.

Disclose a kind of method and apparatus in the people's such as S.H.Gardner that on March 17th, 1998 published the United States Patent (USP) 5,729,557 (Gardner), be used for the forward error recovery of cellular digital wireless communication system is used some kinds of code checks.A value that is known as power long-pending (PP) is all transmitted in each base station, and this value equals base station transmitting power P _BTMultiply by the power level P that receives at the place, base station _BRFor a mobile unit, for determining its suitable transmitting power P _MT, needs are measured the received power P at mobile unit place _MRAnd carry out a calculating.When the path loss of channel was very big, power control was calculated and might be returned a value, and this value is greater than the maximum transmission power ability of mobile unit.In this case, mobile unit is selected a kind of lower code check.The sensitivity of base station receiver improves along with the reduction of code check, so its result is identical with the raising transmitting power.In preferred embodiment, the present invention has used three kinds of different code checks.In most of the cases, employed code check is 2/3, but when mobile unit determined that it need be than the bigger transmitting power of the transmitting power that can provide, code range changed into 1/2, and under some strict situation, it is 1/3 that code check is changed.

September in 1994 people such as disclosed Tetsuyoshi on the 30th JP6-276176 (Tetsuyoshi) in a kind of like this method is disclosed, by formulating some fragment speed, and they are suitably distributed to the respective remote station, thereby can reduce to separate the inter-signal interference of timing from the signal at respective remote station.When the power level of received signal is to detect detected by received power at the beginning, or by from the signal of distant station detected the time, fragment speed determines that circuit just judges the anti-spread demodulation that this received power level has caused strong jamming and signal.The fragment speed that is occurred in this case is changed, and notifies this distant station by a fragment rate notification circuit.In distant station, spreading code produces corresponding to the fragment speed of being notified by the base station.The spreading code that is produced is provided for the spread spectrum modulating part, so that it is carried out band spectrum modulation, and is sent to the base station.Like this, an anti-extension process is carried out with described fragment speed in the base station, can reduce the interference at distant station place.

In the system of prior art, the estimation of past of signal-to-jamming ratio is used to regulate transmitter power.Because the decline of radio channel, concerning optimal power control, using the past estimation of the SNR that is received is not a kind of suitable technique.Resemble the future anticipation that the present invention uses channel power like this without any a prior art, also resemble the present invention and set optimum thresholding according to the probability density function of this channel like this, to control transmitter gain and speed without any a prior art.

An object of the present invention is to provide and resemble WCDMA system such a kind of communication system and method for operation, they have the Adaptive Modulation that is used to improve system throughput, channel capacity and transmitting power control.

Another object of the present invention provides a WCDMA system and method for operation thereof, and they have utilized channel estimating and seamless rate conversion (SRC)/transmitting power control (TPC) logic, are used for the management of power and speed.

Another object of the present invention provides a kind of WCDMA system and method for operation, and they have the adaptive power management that has improved, and this management uses the transmitter power control bit in the WCDMA transmission time slot.

Another object of the present invention provides a kind of WCDMA system and method for operation, and they have the adaptive power management that has improved, and this management used the guiding position that is used for the self adaptation transmitter diversity.

Make treating capacity, control channel capacity/transmitting power maximum, and keep to realize above-mentioned these and other objects, feature and advantage by using following means: (ⅰ) channel estimating and SRC/TPC logic in a kind of WCDMA system and method for operation of the connectedness between base station and the travelling carriage; (ⅱ) the transmitter power control bit in WCDMA transmitter time slot and (ⅲ) self adaptation transmitter diversity (ADT).The transmitter of base station or travelling carriage comprises a pilot channel, it can send control and power control signal between travelling carriage and base station, so that according to the decay in future of the channel power predicted and probability density function (pdf) thereof transmitter is reconfigured.Use 1/2 Viterbi encoder and interleaving technology that information signal is encoded.Use quaternary PSK (QPSK) modulation to shining upon through the data bit that interweaves.It is multiplexed to use pilot channel that the QPSK data are carried out, and the corresponding long code of orthogonal code length of being decided through consultation during by suitable orthogonal code and with call setup is expanded the QPSK data.The output of transmitter is provided for diversity (diverse) antenna, is used for communicating by letter reliably with receiver.The receiver of forward direction and reverse system is substantially the same.Data are received by two diversity antennas.The matched filter that a coherent rake receiver can be provided is delivered in its output, and the channel estimating system that is provided for the place, base station.Decay in future for several milliseconds channels is determined by the channel estimating system.In one embodiment, seamless rate conversion (SRC)/transmitting power control (TPC) logic has been used the channel power of prediction, and sets suitable thresholding, so that the notice transmitter and receiver reconfigures emission rate or power.In this case, according to the threshold value that sets at each WCDMA time slot section start, in the time of within the predetermined channel power level is positioned at a threshold level, revise its emission rate at transmitter and receiver.The specific boot channel is used to call out travelling carriage or base station, revises to be used for SRC.The SRC/TPC logic also is transfused to relevant rate receiver, so that make receiver synchronous with new speed, and provide an output to qpsk demodulator, afterwards, data are deinterleaved, and be provided for a viterbi decoder, so that in the process that an output signal is provided, can provide reliable communication.In another embodiment, according to the channel power thresholding of above-mentioned prediction, the transmitter power control bit has entered transmission time slot.When the channel power of prediction drops under the threshold level, increase transmitter power with a predetermined level.When the channel power of prediction surpasses thresholding, reduce transmitter power with predetermined level.In another embodiment, the base station is to the channel power of the prediction of two diversity antennas of travelling carriage emission.Travelling carriage is compared the performance number of two channels with thresholding, and selects to carry out that antenna of propagating by the good channel path, and it can reduce multiple access and disturb (MAI) and intersymbol interference (ISI).These three embodiment help the WCDMA system to keep being communicated with; By optimizing the power loss minimum that transmitter power or transmitter antenna diversity make travelling carriage; And provide transmitter and receiver reparation and increase capacity.

By the detailed description that following connection with figures is carried out most preferred embodiment, the present invention may be better understood for we, wherein:

Fig. 1 is the schematic diagram of a frame structure in the WCDMA time slot in the system of Fig. 2.

Fig. 2 embodies a base station in the WCDMA system of the principle of the invention and a layout of travelling carriage.

Fig. 2 A is the block diagram of the base station transmitter among Fig. 2.

Fig. 2 B is included in the block diagram of a channel baseband model among Fig. 2.

Fig. 2 C is a block diagram of the receiver of travelling carriage among Fig. 2 or base station.

Fig. 2 D is a block diagram of the travelling carriage transmitter among Fig. 2.

Fig. 3 is a figure of the probability density function (pdf) of channel power, and it has one for two (2) degrees of freedom in Fig. 2 system and meets X ²The stochastic variable that distributes.

Fig. 4 is illustrated in the channel probability density function of each WCDMA time slot section start and the graph of a relation of performance number.

Fig. 5 is the figure of the channel pdf that is split into three equal probability intervals that is used for the system of Fig. 2.

Fig. 6 is the flow chart of the base station transmitter in Fig. 2 system, and it has used transmitter power control (TPC) position in the WCDMA time slot, to be used for power management.

Fig. 7 is with seamless rate conversion (SRC) during to the system executable operations among Fig. 2, the flow chart of the base station transmitter in this system.

Fig. 8 be expression when system modification transmitter ratio, in the system of Fig. 2, the flow chart that extended code is selected.

Fig. 9 has shown when with self adaptation transmitter diversity (ATD) when operating described system the flow chart of the base station transmitter in the system of Fig. 2.

In the WCDMA system, use quadriphase PSK (QPSK) and direct sequence CDMA (DS-CDMA) to come transmit symbol.Fragment speed is 4.096 MHz.Each physical channel all is arranged in the frame structure, and like this, each time slot all is made of 2560 fragments.This is in the document 90 of the IEEE Vehicular TechnologyConference of in May, 1999 publication, it is illustrated in the document of " Channel Estimation for the W-CDMA System, Permance and Robustness Analyses from a Terminal Perspective " by the exercise question that B.Lindof, C.Ostberg and H.Eriksson write.Fig. 1 has illustrated the frame structure 10 of a W-CDMA, and it comprises time slot 0-15.Each frame all comprises guiding position 12 and transmitter power control bit 14.For down link, with data symbols direct symbol is carried out time division multiplexing, and each time slot is all with a direct symbol (4 or 8) group beginning, this guidance code tuple can be used for estimation or predicted channel and carries out synchronously.

The present invention has advised a kind of technology, is used for the Adaptive Modulation of the WCDMA system shown in Fig. 2-2D.It has used a kind of algorithm of the long range prediction that is used for mobile channel, the IEEE Communication Letters that publishes in September, 1998, the 2nd volume, the 9th is interim, among " the Deterministic Channel Modeling and Long Rang Prediction of FastMobile Radio Channels " that is write by T.Eyceoz, A.Duel-Hallen and H.Hallen (Eyceoz) etc. this algorithm is illustrated.

In Fig. 2, base station 101 is linked on the travelling carriage 102 by channel 103, in Fig. 2 A-2D further show.

In Fig. 2 A, the transmitter 104 of base station or forward direction system comprises a terminal 105 that is used to receive a back emitted machine signal.This signal is used as input and offers orthogonal code generator 106 and interleaver 107, and interleaver 107 is used for merging with back emitted machine signal and through the data source 108 after 110 processing of Viterbi encoder.Separated and enter first and second channels that are coupled with quadriphase PSK (QPSK) unit 112, real part and imaginary part, A and B as the treated signal of data symbols.Multiplexer 116 retrieval is from the output of the channel A channel B of QPSK unit 112, and with the interior data symbols of Frame 20 sequences (referring to Fig. 1) pilot signal 114 carried out time division multiplexing, and this will be described in detail following.The OFDM sign indicating number 106 that use is revised with extended code or long code 118 sends to mobile receiver 150 (please see Figure 2C) with the Frame in channel A and the B, as will describing in detail hereinafter.

In Fig. 2 B, shown the baseband model 130 that is used for channel A and B.Each channel is modeled as 131 and time orientation flat fadings of additive white Gaussian noise (AWGN) (Time Bearing Flat Fading) (TBFF) 132, wherein can ignore the selection decline that causes owing to multipath.

In Fig. 2 C, travelling carriage or reverse system receiver 150 are similar to base station receiver or forward direction receiver 170 (seeing also Fig. 2).Each receiver all comprises the matched filter that is used for antenna diversity 152,154 that is positioned at receive channel A and B.The output of matched filter is sent to coherent rake receiver 156 and channel estimating or estimating system 158.The channel estimating system determines to decay the future of channel with several milliseconds, and is illustrated in above-mentioned Eyceozarticle (supra.).This time interval is enough to allow base station and travelling carriage that their transmitter and receiver is reconfigured.SRC/TPC logical device 160 utilizes the prediction of channel power and channel coefficients to notify transmitter and receiver, make it be higher than according to channel power or be lower than threshold level and to channel power with and/or channel speed reconfigure.This will describe in following Fig. 7 and 8.SRC/TPC logical one 60 provides input to Rake receiver 156 and deinterleaver 162, so that carry out during the data processing in QPSK equipment 164 and afterwards, adjust the transmission rate in channel A and the B.Which antenna is the SRC logic also can determine in received signal more accurately, and notifies its transmitter or distance transmitter to use this antenna, is used for to reducing the emission that multiple access disturbs the base station of (MAI).Deinterleaver 162 provides an output to viterbi decoder 166, and viterbi decoder provides an output signal 168 to the user.Specific boot channel 114 is used to notify travelling carriage or base station to carry out and reconfigures.

In Fig. 2 D, travelling carriage transmitter or reverse system transmitter 180 comprise the data source 182 of code element, in Viterbi encoder 184 it is encoded, and it are divided into channel A and B.In 10 milliseconds of time periods, these signals are handled by interleaver 186 and speed 1/2 Viterbi encoder.In qpsk modulator 188 to shining upon through the data bit that interweaves.In multiplexer 190, use from 114 pairs of QPSK data of pilot signal of receiver 150 and handle.(referring to Fig. 2 C) OFDM unit 192 uses suitable orthogonal code that expansion is carried out in the output of the multiplexer in channel A and the B, and afterwards, the length of the orthogonal code of being decided through consultation during with call setup is corresponding and add a long code 194.Before described channel is delivered in the output of channel A and B, in pulse crack (pulse chap), it is carried out over-sampling.

In wireless system, transmission channel is modeled as Rayleigh distributed usually.Therefore, channel power has a kind of X that contains 2 degrees of freedom ²Probability distribution.Following equation has illustrated this relation:

$p\left(y\right)=\frac{1}{2{\mathrm{\σ}}^2}{e}^{{-y/2\mathrm{\σ}}^2}$

Wherein, P (y) is channel power pdf _Y=α2;

σ ²=variance.

$p\left({\mathrm{\γ}}_b\right)=\frac{1}{\stackrel{\‾}{{\mathrm{\γ}}_b}}{e}^{-{\mathrm{\γ}}_b/\stackrel{\‾}{{\mathrm{\γ}}_b}}$ Signal to noise ratio (snr) at the receiver place is

Fig. 3 has shown the obedience X to 2 degrees of freedom ²The probability density function (pdf) 30 of the stochastic variable that distributes, exercise question is for having carried out detailed explanation to it in the document of " John Proakis " in the DigitalCommunications of the New York of nineteen ninety-five McGraw Hill.Utilize long apart from channel estimating handle, the predicted time of 10ms in a W-CDMA frame, the channel power abridged table that base station (BS) can predict travelling carriage (MS).The pdf of predicted channel power in theory should be similar among Fig. 3 that.

We implement an experiment, to prove the performance of the processing that is proposed.In this experiment, our supposition is to the section start of each time slot in the frame duration, the BS prediction of channel power is desirable, 4 pdf40 that independently obey the channel power of same distribution (IndependentIdentical Distributed) (II D) are calculated, and it is shown among Fig. 4.

By definition, estimate the probability of error in order to lower integral for a BPSK (2 BPSK and QPSK be equal to) system, ${\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="0012920600211.png"\; state="\{\{state\}\}">P</figure-callout>}}_2=\underset{0}{\overset{\&infin;}{\&Integral;}}{P}_2\left({\mathrm{\&gamma;}}_b\right)p\left({\mathrm{\&gamma;}}_b\right)d{\mathrm{\&gamma;}}_b$ Resulting system is estimated in order to lower integral: ${\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="0012920600211.png"\; state="\{\{state\}\}">P</figure-callout>}}_2=\frac{1}{2}[1-\sqrt{\frac{\stackrel{\&OverBar;}{{\mathrm{\&gamma;}}_b}}{1+\stackrel{\&OverBar;}{{\mathrm{\&gamma;}}_b}}}]$

In the present invention, the pdf of channel power is divided into several intervals, and wherein each interval probability all equates.Fig. 5 has shown the pdf in three intervals of channel power.

Be divided into three equal probability interval (0-A at pdf; A-B; B-$) under the situation, the area under each interval exponential curve equals 0.333.In other words, the probability of system works operation under no good, specified and high channel status is identical.In three Interval System of Fig. 5, the above-mentioned equation that is used for channel power becomes following form.In following equation, use its corresponding SNR value that each interval A and B are carried out standardization $P_{}$ ${}_2=\underset{0}{\overset{A}{\&Integral;}}{P}_2\left({\mathrm{\&gamma;}}_b\right)p\left({\mathrm{\&gamma;}}_b\right)d{\mathrm{\&gamma;}}_b+\underset{A}{\overset{B}{\&Integral;}}{P}_2\left({\mathrm{\&gamma;}}_b\right)p\left({\mathrm{\&gamma;}}_b\right)d{\mathrm{\&gamma;}}_b+\underset{B}{\overset{\&infin;}{\&Integral;}}{P}_2\left({\mathrm{\&gamma;}}_b\right)p\left({\mathrm{\&gamma;}}_b\right)d{\mathrm{\&gamma;}}_b$

Because the predicted power level of each transmission time slot can obtain at travelling carriage (MS), so system can be configured its transmitter at the place that begins of each time slot.In this case, MS can optimize its transmitter, so that make the probability of error minimum at receiver place, base station (BS).By means of the adaptive power control through improving of having used following technology, this optimization has improved system quality: transmitter power control (TPC) position that (a) provides in the W-CDMA time slot; (b) use the seamless rate of guiding position to change (SRC), and the self adaptation transmitter diversity (ATD) that (c) has used the guiding position, concrete grammar is as follows:

A. general process

The MS transmitter by changing a spreading coefficient (SF) or antenna, is revised the transmitter power ratio according to the thresholding that is set by BS.In this case, or MS or BS calculates " B﹠amp; C " value (Fig. 5).These values are selected, made the time service of system 33% in low-power interval (0-A), 33% time service is in the power level of optimizing (A-B), also has 33% time service in higher power interval (B-$).Because total average power is 1, so the long term average power of three Interval System also is 1.

B．TPC

When system works in TPC pattern following time, and when the channel power of prediction fell in the scope of " A-0 ", system just increased the transmitter power of 3dB.When the channel power of prediction surpassed " B " scope, system just reduced the transmitter power of 3dB.And final, when the channel power of predicting is positioned at " A﹠amp; B " between the time, system does not just adjust.Fig. 6 shown when system works in TPC pattern following time, flow process Figure 60 of BS transmitter, its flow process is as follows:

Beginning, system receives a frame of seamless rate conversion instruction (SRC) 62.Carry out test 64, in this test, detect the TPC position in each time slot.When the power (P) of prediction is positioned at the interval of 0-A, just in step 66, transmitter power is increased 3dB by reducing ratio.When the power (P) of prediction surpassed the B interval, in step 68, system reduced 3dB by increasing ratio with the transmitter ratio.When the power of predicting was between A and B interval, system did not adjust transmitter power.

C．SRC

Fig. 7 has shown flow process Figure 70, and it has illustrated the operation of system under seamless rate conversion (SRC) pattern.At the beginning, system receives a frame of seamless rate conversion instruction (SRC) 72.Carry out test 74, in this test, detect the SRC position in each time slot.When the channel power of prediction falls into " A " interval, just in step 76, reduce emission ratios, and use a longer extended code (2*SF).In step 78, when the channel power of prediction surpasses " B " interval, just increase the transmitter ratio, and use a shorter extended code (1/2*SF).And final, when the channel power of predicting is positioned at " A﹠amp; B " between the time, system does not just adjust.

In Fig. 8, shown with algorithm 80 and regulated extended code C (1).When the channel power of prediction drops on thresholding when following, just reduce the ratio of being launched, and use longer extended code.In frame 84, when surpassing threshold level, just extended code is doubled.In frame 86 and 88, extended code is added to 4 and 8.When the channel power of prediction surpasses thresholding, just increase the transmitter ratio, and use extended code, as shown in frame 85,87 and 89 with shorter extensive ratio.And when the channel power of prediction is positioned at above-mentioned threshold level, just do not adjust extended code.

D．ATD

Fig. 9 has illustrated when making system works with the self adaptation transmitter diversity, flow process Figure 90 of BS transmitter.When system works during in the ATD pattern, the BS receiver is two input receiver predicted channel power after a frame that receives power (P) instruction from step 92.BS launches the channel power value of the prediction of a frame to the MS receiver by the guiding position.Handle 60,70 similarly to TPC or SRC, in step 94, MS compares this performance number and thresholding, and selection can be by a transmitting antenna #1 or #2 who transmits preferably in two transmission paths.This processing can reverse, and can change the effect of BS and MS, make BS carry out a day line options, and MS carries out prediction.

On the whole, disclosed WCDMA system has the control of adaptive channel power, the seamless rate conversion that it has utilized the transmitter power control bit (TPCB) in the frame transmission time slot and has used the guiding position with and/or the self adaptation transmitter diversity.The WCDMA system can support variable data transfer rate, this is by its Receiver And Transmitter being configured to when the call setup determined data transfer rate or by during the transmission, by means of the adjustment of the orthogonal code length that produced is changed adaptively, thereby realize.The guiding relevant with the individual data channel set channel and is loaded with control signal, transmits and receives power level so that regulate.As a result, treating capacity is maximized, and channel capacity is improved, and simultaneously, has reduced transmitting power, and has kept the connectedness in the system on the whole.

Though only use most preferred embodiment to show and the present invention be described, do not break away under the situation of defined the spirit and scope of the invention in accessory claim, also can obtain various variations.

Claims (21)

1. a Wideband Code Division Multiple Access (WCDMA) (" WCDMA ") system comprises a base station and a travelling carriage;

A channel comprises a baseband signal with variable transmission rate, and comprises a pilot channel that is coupled with described base station and described travelling carriage;

Respond the device of described baseband signal, be used for the following power attenuation on the predicted channel; And

Respond the device of described channel estimating device,, make its power attenuation that transmission rate is reconfigured according to described prediction so that notify transmitter and receiver by pilot channel.

2. system as claimed in claim 1 also is included in and sets up a power threshold in the channel.

3. system as claimed in claim 2 also comprises a kind of device, when being used for channel power in described prediction greater than described thresholding, increases described transmission rate.

4. system as claimed in claim 2 also comprises a kind of device, is used for falling described transmission rate when following at described predicted channel power, reduces described transmission rate.

5. system as claimed in claim 1 also comprises a kind of like this device, is used for the data-signal on the channel of the corresponding long code of length that is in the orthogonal code of using the OFDM sign indicating number and deciding through consultation during with transmission is transmitted.

6. system as claimed in claim 1 also comprises a qpsk modulator, is used to handle described baseband signal.

7. system as claimed in claim 1 also comprises the described pilot signal of usefulness is carried out multiplexed to described baseband signal; And

The corresponding long code of length of the orthogonal code of using suitable orthogonal code and the time deciding through consultation with transmission is expanded described multiplexed signal.

8. system as claimed in claim 1 comprises also being used for device that the described baseband signal in frame sequence is sent that each frame comprises some transmission time slots;

The device that comprises pilot signal group and the transmission power control signal group in each time slot;

Be used to detect the device of the described transmission power control signal in each time slot;

Be used for detecting the device of each time slot of the power control signal that is used to transmit the described channel power of representative; And

A kind of device is used for channel power in described prediction and drops on thresholding when following, increases transmitter power; And

When the channel power of described prediction surpasses thresholding, reduce transmitter power.

9. system as claimed in claim 1 also comprises the device that is used for a baseband signal in the received frame sequence, and each frame all comprises the channel power value;

Be used to detect the device of the performance number of two antennas relevant with described travelling carriage with described base station; And

Be used for the performance number of each antenna with after thresholding is compared, select the device of a transmitting antenna.

10. in a kind of Wideband Code Division Multiple Access (WCDMA) (" WBCDMA ") system of a pilot channel that is coupled at the transmitter and receiver of the transmitter and receiver that comprises a base station, a travelling carriage, double-channel that its each bar channel all comprises a baseband signal with variable transmission rate and with described base station and described travelling carriage, be used to the method for the treatment of capacity, channel capacity and the transmitting power control of the system that improves, this method may further comprise the steps:

Predict the following power attenuation on the described channel; And

By described pilot channel, notify described transmitter and receiver, make its power attenuation according to described prediction, transmission rate is reconfigured.

11., further comprising the steps of as the method for claim 10:

In described channel, create a power threshold.

12., further comprising the steps of as the method for claim 11:

When the channel power of described prediction surpasses described thresholding, improve transmission rate.

13., further comprising the steps of as the method for claim 12:

When the channel power of described prediction drops on the thresholding that sets when following, reduce described transmission rate.

14., further comprising the steps of as the method for claim 13:

According to described transmission rate, on the channel that uses OFDM sign indicating number and long code, transmit a data-signal.

15., further comprising the steps of as the method for claim 10:

Handle described baseband signal with a qpsk modulator.

16. method as claimed in claim 1 also comprises step:

Carry out multiplexed with described pilot signal to described baseband signal; And

With a kind of suitable orthogonal code and with the corresponding long code of described transmission rate to expanding through multiplexed signal.

17., also comprise step as the method for claim 16:

Described baseband signal in the transmission frame sequence, each frame all comprises some transmission time slots;

In each time slot, comprise pilot signal group and transmission power control signal group;

Detect the transmission power control signal in each time slot;

Detection is used to transmit each time slot of the power control signal of representing described channel power;

When the channel power of described prediction drops on described thresholding when following, increase transmitter power; And

When the channel power of being predicted surpasses described thresholding, reduce transmitter power.

18., also comprise step as the method for claim 10:

A baseband signal in the received frame sequence, each frame all comprises the channel power value;

Detect the described performance number of two antennas relevant with described travelling carriage with described base station; And

With after a thresholding is compared, select a transmitting antenna in the performance number that will be used for each antenna.

19. system as claimed in claim 1 wherein is used for the device that described transmission rate reconfigures is also comprised:

Be used to define the device of a channel power probability density that is divided into three equal first, second and the 3rd probability interval; And

Be used to make the device of system works under the transmitting power control model, wherein,, then increase the power of transmitter if the following power attenuation of described prediction falls into described first probability interval; If the following power attenuation of described prediction falls into the 3rd probability interval, then reduce the power of described transmitter, if the following power attenuation of being predicted falls into described second probability interval, then described transmitter is not carried out power adjustments.

20. system as claimed in claim 1, wherein, the device that described transmission rate is reconfigured also comprises:

Be used to define the device of a channel power probability density that is divided into three equal first, second and the 3rd probability interval; And

Be used to make the device of described system works in the seamless rate translative mode, wherein, one frame comprises the seamless rate conversion instruction position of expression predicted channel power, thus, if the future of described prediction, decay fell into described first interval, then reduce the emission rate of transmitter, and use long extended code; If the following power attenuation of described prediction falls into described the 3rd interval, then reduce the emission rate of described transmitter, and use one than short extended code, if and the following power attenuation of described prediction is not carried out power adjustments to the emission rate of described transmitter when falling into described second probability interval.

21. system as claimed in claim 1 wherein is used for the device that described transmission rate reconfigures is also comprised:

Make the device of described system works under the self adaptation transmitter diversity mode, wherein, the following channel power attenuation of the some antennas of station prediction, and by the guiding position sends to another station with the channel power value of the described prediction of each antenna;

On another station, be used for performance number and the device that thresholding compares with the described prediction of each antenna; And

On another station, be used to choose the device that the antenna with the maximum predicted performance number that surpasses described thresholding is carried out the signal transmission.

Images