CN1479471A - Method fast forward power optimizing channel for CDMA receiver - Google Patents

Abstract

Since mobile station (terminal) sends power control bit to base station, thus the mobile station (terminal) knows amplitude variation in forward channel. In estimated amplitude of control signal, using S/N estimation, power control command, weight value adjustment and time delay generates signal proportional to amplitude of flow channel. The signal generated can be utilized in MRC and CDMA2000 receiver.

Description

The method of CDMA receiver fast forword power optimization channel

Technical field:

The present invention relates to the auxiliary maximum rate synthetic (MRC) of control signal of fast forword power optimization channel in a kind of CDMA receiver, belong to mobile communication and make the field.

Background technology:

In the two generation wireless cellular technology CDMA1 that use CDMA technology, a kind of control signal can be broadcasted to mobile radio station (terminal) in the base station, utilize sort signal mobile radio station (terminal) thus can be in the process of voice or transfer of data estimate that phase place carries out the consistent of forward traffic channel with amplitude and receives and MRC the MRC that so-called control signal that Here it is is assisted.In these systems, the signal amplitude of control signal amplitude and traffic channel is proportional.When traffic channel was carried out MRC, the MRC coefficient should be the phase place and the amplitude of traffic channel at receiver.But because the phase/amplitude of its phase/amplitude and control signal is proportional, so the phase/amplitude of being come by control signal can be used as the MRC coefficient of traffic channel.

In CDMA2000, mobile radio station (terminal) needs in the process of voice/data transmission to the frequency transmission power control position (PCB) of base station with 800HZ, and the base station just can be carried out the adjustment of so-called fast forword power control to forward traffic channel like this.Control signal is a constant power in the CDMA1 technology.The result is: the amplitude of traffic channel no longer becomes ratio with the amplitude of control channel.Example: if the MRC method of application of aforementioned will cause the performance of non-optimum.

Summary of the invention:

Purpose of design: the present invention discloses a kind of simple method, and the MRC that it has strengthened the CDMA1 receiver enables to be used for the CDMA2000 receiver.Usually the performance optimization of CDMA1 receiver in the CDMA1 system is that the CDMA2000 system of FPC has obtained reservation having new features, and this has caused keeping accepting the decline of the required average transmitting power of voice/data transmission quality.Because each transmission all is the interference of every other transmission in cdma system, so this has further increased power system capacity again.

Design: because mobile radio station (terminal) is to the base-station transmitting-power control bit.Therefore mobile radio station (terminal) can be known the amplitude variations of forward channel, in the control signal amplitude of estimating, pass through signal-to-noise ratio (snr) estimation, power control command, weights adjustment and time-delay, produce and the proportional signal of traffic channel amplitude, thereby can be used for MRC.The auxiliary MRC of control signal comprises multiplicator, the Walsh decoder, the pilot tone decoder, channel simulation, the deconvolution sign indicating number, data accumulator, the noise estimation, power control, numerical value is adjusted, time-delay and deconvolution sign indicating number constitute, initial data is divided into two-way through multiplicator: the one tunnel through the Walsh decoder to the deconvolution sign indicating number, another road is through the pilot tone decoder, channel simulation is to the deconvolution sign indicating number, deconvolution sign indicating number decoding back to data accumulator adds up the back to the deconvolution sign indicating number, be divided into two-way behind the deconvolution sign indicating number uncoiling: 1. one the tunnel estimates that through noise one the road to transmitting base station to power control, one the tunnel gets maximum mixing ratio output to the decoding of deconvolution sign indicating number after data are adjusted to delay process; 2. another road is to maximum mixing ratio output.

The present invention compares with background technology, and the MRC that it has strengthened the CDMA1 receiver enables to be used for the CDMA2000 receiver.

Description of drawings:

Fig. 1 is the auxiliary MRC system schematic of control signal.

Fig. 2 is that weights are adjusted schematic diagram.

Embodiment:

Fig. 1 has shown the CDMA receiver system module map that realizes this kind method.Described a FINGER among the figure, and had only the part relevant to be showed with producing MRC output.In the CDMA2000 system, MRC output need be delivered to the Viterbi=Turbo channel decoder, thereby recovers user data, and channel decoder does not occur in the drawings yet.

The original I of Incoming and Q channel data are to obtain by the series of standards acceptor circuit that does not have on the figure to show: antenna, reception amplifier, radio frequency lead to the analog digital converter of (BANDPASS) filter, receiving automatic gain controlling circuit, IF-to-baseband blender and output original I and Q data frequently to intermediate frequency blender, reception, and these data all utilize the standard time follow-up mechanism to carry out the sequential alignment by FINGER.All these data all are standard techniques, are not that CDMA institute is peculiar.

Among Fig. 1, original I and Q data are at first rejected CDMAPN convolution code (spreading code) by a multiplicator (QDS) from signal.Consequential signal is divided into two-way, and one the tunnel is sent to Walsh Decover circuit, takes out noisy data-signal version, and Pilot Decover circuit is sent on another road, takes out noisy control signal version.QDS, Walsh Decover and Pilot Decover circuit all are what what's frequently heard can be repeated in detail in the CDMA field, can make by suitable experiment.In channel estimation module, control signal forms complicated conjugate through filtering.Have the possible complicated filter of many kinds to realize at present, each all can provide the approximate value of different weight coefficients according to common MRC technology.

The reflector of base station generally is put into data independently in I and the Q channel.Yet channel disturbance makes these signal phase mutual interference mix, and the dateout of Walsh Decover circuit be it is said what phase place was rotated.The multiplication that these phase place rotations are marked by " derotate data " title is eliminated: the dateout and the MRC weight coefficient of Walsh Decover circuit multiply each other, and channel disturbance also causes the amplitude time to time change of data on flows signal simultaneously.Before the data of the data of this FINGER and other RAKE FINGER are synthetic, thereby data-signal needs obtain synthesizing of optimization according to own amplitude adjustment.If control signal amplitude and flow signal amplitude are proportional, the multiplication (multiply by the MRC weight coefficient) of then eliminating the phase place rotation should be able to be obtained the correct weight of this FINGER (being used for the synthetic of a plurality of FINGER), yet owing to the power control command that mails to the base station can make flow signal power along with the time changes, these weights need be adjusted with method discussed below.Because it all is the same that this weight is adjusted all FINGER of factor pair,, it once gets final product so only need using later in the last synthesizing multi-path of data mixing device footpath data.

In order to realize quick FPC, mobile radio station (terminal) must be estimated the sir value of MRC output.The CDMA2000 standard is that regulation SIR estimates and must do, but does not but stipulate how to do.SIR estimates just to use simply in Fig. 1 not within this paper scope " SIR Estimate " mark represents.

For 1 power command forming appointment (+expression power increases,--expression power reduces), the SIR estimated value can compare with the set point in the power control module.If the SIR estimated value is higher than set point, power reduces order will be sent to the base station; If the SIR estimated value is lower than set point, power strengthens order will be sent to the base station.The SIR set point is by outer loop circuit (outer FPCloop) institute's initialization of FPC and adjustment (do not show on the figure, at this paper scope is not discussed).

According to power adjustment commands, the weights adjusting module will be finished adjustment work, among the present Fig. 2 of this module detail list.Strengthen order if sent power, the weights of accumulation are adjusted the factor will multiply by C1; Reduce order if sent power, the weights of accumulation are adjusted the factor will multiply by C2.Power adjustment commands has been represented to be the power enhancing of unit or to reduce that with fixed step size (decibel) we are referred to as power step size (Power_step) here.Power step size is 0.5 decibel in most CDMA2000 networks.The relation of C1 and C2 and step-length is as follows: $c1={10}^{\mathrm{power}\_\mathrm{step}/20};$ $c2={10}^{-\mathrm{power}\_\mathrm{step}/20}.$ In CDMA2000, data on flows is unit encoding/a be decoded as data block with 20 milliseconds length.For the weights adjustment that makes limited precision realizes more simple and easy and do not have the performance loss of decoder, can be reset be 1 to its weights adjusted value when each coding decoder is started working.

At last, because cdma system is based on time slot, and round-trip signal delay is less than a time slot, and the time difference that power adjustment commands is issued between this order of base station applies can accurately be obtained.Same delay (the DELAY module among Fig. 1) is used in MRC output and adjusts before (utilizing the MRC weights) in mobile radio station (terminal).

What need to state in the explanation of this method is to form and use the method that the MRC weights are adjusted.This method utilizes soft input channel decoder that the channel-decoding of near optimal is provided.

What need understand is: the foregoing description is just illustrative to the present invention, rather than limitation of the present invention, and any innovation and creation that do not exceed connotation of the present invention all fall within the scope of protection of the present invention.

Claims (2)

1, a kind of method of CDMA receiver fast forword power optimization channel, it is characterized in that: mobile radio station (terminal) is to the base-station transmitting-power control bit, mobile radio station (terminal) is known the amplitude variations of forward channel, by signal-to-noise ratio (snr) estimation, power control command, weights adjustment and time-delay, generation is used for MRC with the proportional signal of traffic channel amplitude in the control signal amplitude of estimating.

2, the method of CDMA receiver fast forword power optimization channel according to claim 1, it is characterized in that: the auxiliary MRC of control signal comprises multiplicator, the Walsh decoder, the pilot tone decoder, channel simulation, the deconvolution sign indicating number, data accumulator, the noise estimation, power control, numerical value is adjusted, time-delay and deconvolution sign indicating number constitute, initial data is divided into two-way through multiplicator: the one tunnel through the Walsh decoder to the deconvolution sign indicating number, another road is through the pilot tone decoder, channel simulation is to the deconvolution sign indicating number, deconvolution sign indicating number decoding back to data accumulator adds up the back to the deconvolution sign indicating number, be divided into two-way behind the deconvolution sign indicating number uncoiling: 1. one the tunnel estimates that through noise one the road to transmitting base station to power control, one the tunnel gets maximum mixing ratio output to the decoding of deconvolution sign indicating number after data are adjusted to delay process; 2. another road is to maximum mixing ratio output.

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