CN104079383A - Acquisition method and device of channel quality indicator (CQI) and user terminal - Google Patents

Abstract

The invention provides an acquisition method and device of a channel quality indicator (CQI) and a user terminal, and belongs to the field of mobile communication. The acquisition method of the CQI comprises the following steps: calculating an SIR (Signal to Interference Ratio) estimated value and an SNR (Signal to Noise Ratio) estimated value respectively; determining a final estimated value according to the calculated SIR estimated value and SNR estimated value; and determining the CQI by using the final estimated value. By adopting the technical scheme of the invention, the robustness of a CQI system can be enhanced, and the reliability of CQI feedback is enhanced.

Description

Acquisition methods, device and the user terminal of channel quality indication

Technical field

The present invention relates to moving communicating field, refer to especially a kind of acquisition methods, device and user terminal of channel quality indication.

Background technology

At TD-SCDMA(Time Division-Synchronous Code Division Multiple Access, TD SDMA) in system, HSDPA (High Speed Downlink Packet Access, high speed downlink packet access) be a kind of high rate data transmission technology, can significantly improve the transmission rate of downlink data.HSDPA is by short frame, AMC(Adaptive Modulation and Coding in physical layer, Adaptive Modulation and Coding), HARQ (Hybrid Automatic Repeat Request, mixed automatic retransfer request) and the channel control technology such as fast dispatch, can improve the service experience of down user data.

In these channel control technologys, AMC has the following advantages: be in the more user of good position and can obtain higher data rate, can improve like this average throughput of community; Do not changing under the prerequisite of through-put power, AMC can reduce conflict by changing modulation code version.Particularly, AMC process comprises following steps:

(1) user terminal (UE) measure channel quality, then by measurement result, generate CQI (channel quality indication), CQI comprises RTBS(Recommended Transport Block Size, recommend transmission block size) and RMF (Recommended Modulation Format recommends modulation format).In current CQI system, there is the correspondence table of channel quality and CQI, by searching this form, just can determine CQI according to the measurement result of channel quality;

(2) UE feedback CQI is to NodeB;

(3) NodeB changes coded system according to the CQI of UE feedback.

By said process, can find out, CQI is a very important feedback information in wireless communication system, NodeB decides next step transmission mechanism by CQI, CQI will directly affect the throughput of wireless communication system, so CQI feedback need to have very high reliability.

Summary of the invention

The technical problem to be solved in the present invention is to provide a kind of acquisition methods, device and user terminal of channel quality indication, can strengthen the robustness of CQI system, and then improves the reliability of CQI feedback.

For solving the problems of the technologies described above, embodiments of the invention provide technical scheme as follows:

On the one hand, provide a kind of acquisition methods of channel quality indication, comprising:

Difference calculated sir SIR estimated value and signal noise ratio SNR estimated value;

According to the SIR estimated value calculating and SNR estimated value, determine final estimated value;

Utilize described final estimated value to determine channel quality indicator (CQI).

Further, in such scheme, the SIR estimated value that described basis calculates and SNR estimated value determine that final estimated value comprises:

According to the difference of described SIR estimated value and SNR estimated value, determine described final estimated value.

Further, in such scheme, the described difference according to described SIR estimated value and SNR estimated value determines that described final estimated value comprises:

When the difference of described SIR estimated value and SNR estimated value is less than predetermined threshold value, determine that final estimated value is the mean value of described SIR estimated value and SNR estimated value;

When the difference of described SIR estimated value and SNR estimated value is not less than predetermined threshold value, determine that final estimated value is the smaller value of described SIR estimated value and SNR estimated value.

Further, in such scheme, describedly utilize described final estimated value to determine that CQI comprises:

Utilize described final estimated value to search default final estimated value and the correspondence table between CQI, determine the CQI corresponding with described final estimated value.

Further, in such scheme, describedly calculate respectively SIR estimated value and SNR estimated value comprises:

(1) by step a～c, calculate SIR estimated value:

Step a: utilize denoising channel estimating CHE result to calculate effective CHE number of path;

Step b: calculate respectively initial CHE result power and and the power of denoising CHE result and, and according to the CHE number of path obtaining, initial CHE result power and and power and definite interference value interference and the signal power SP of denoising CHE result;

Step c: calculate SIR estimated value SIR by following formula:

SIR_linear＝SP/interference

SIR＝10*log(SIR_linear/10)；

(2) by steps d～e, calculate SNR estimated value:

Steps d: to incoming symbol delivery, and carried out hard decision and obtained hard decision result on each symbol before demodulation;

Step e: according to hard decision result calculating noise power NP, calculate SNR estimated value SNR by following formula:

SNR_linear＝1/NP

SNR＝10*log(SNR_linear)。

The embodiment of the present invention also provides a kind of acquisition device of channel quality indication, comprising:

Computing module, for difference calculated sir SIR estimated value and signal noise ratio SNR estimated value;

Processing module, for determining final estimated value according to the SIR estimated value and the SNR estimated value that calculate;

Determination module, for utilizing described final estimated value to determine channel quality indicator (CQI).

Further, in such scheme, described processing module is for determining described final estimated value according to the difference of described SIR estimated value and SNR estimated value.

Further, in such scheme, when described processing module is less than predetermined threshold value specifically for the difference when described SIR estimated value and SNR estimated value, determine that final estimated value is the mean value of described SIR estimated value and SNR estimated value; When the difference of described SIR estimated value and SNR estimated value is not less than predetermined threshold value, determine that final estimated value is the smaller value of described SIR estimated value and SNR estimated value.

Further, in such scheme, described determination module, specifically for utilizing described final estimated value to search default final estimated value and the correspondence table between CQI, is determined the CQI corresponding with described final estimated value.

Further, in such scheme, described computing module comprises:

The first calculating sub module, be used for utilizing denoising channel estimating CHE result to calculate effective CHE number of path, calculate respectively initial CHE result power and and the power of denoising CHE result and, and according to the CHE number of path obtaining, initial CHE result power and and power and definite interference value interference and the signal power SP of denoising CHE result, by following formula, calculate SIR estimated value SIR:

SIR_linear＝SP/interference

SIR＝10*log(SIR_linear/10)；

The second calculating sub module, for before demodulation to incoming symbol delivery, and on each symbol, carry out hard decision and obtain hard decision result, according to hard decision result calculating noise power NP, by following formula, calculate SNR estimated value SNR:

SNR_linear＝1/NP

SNR＝10*log(SNR_linear)。

The embodiment of the present invention also provides a kind of user terminal, comprises the acquisition device of channel quality indication as above.

Embodiments of the invention have following beneficial effect:

In such scheme, in conjunction with SIR estimated value and SNR estimated value, determine final estimated value, and utilize final estimated value to determine channel quality indication.Technical scheme of the present invention is carried out under the prerequisite of large change TD-SCDMA receiving terminal not needing, and can accurately obtain CQI, and then improves the reliability of CQI feedback.

Accompanying drawing explanation

Fig. 1 is the model schematic diagram of CQI algorithm;

Fig. 2 is the schematic diagram of SIR CQI algorithm;

Fig. 3 is the schematic diagram of initial CHE result under VA120 channel;

Fig. 4 is the schematic diagram of denoising CHE result under VA120 channel

Fig. 5 is the planisphere under awgn channel;

Fig. 6 is the planisphere under VA120 channel;

Fig. 7 is the analog result schematic diagram that SIR CQI algorithm obtains;

Fig. 8 is the schematic diagram of SNR CQI algorithm;

Fig. 9 be under QPSK pattern when SNR actual value is higher, the symbol constellation schematic diagram before demodulation;

Figure 10 be under QPSK pattern when SNR actual value is lower, the symbol constellation schematic diagram before demodulation;

Figure 11 is used different SNR that the analog result schematic diagram of the SNR estimated value obtaining is set under QPSK pattern;

Figure 12 is used different SNR that the analog result schematic diagram of the SNR estimated value obtaining is set under 16QAM pattern;

Figure 13 is used different SNR that the analog result schematic diagram of the SNR estimated value obtaining is set under 64QAM pattern;

Figure 14 is the schematic flow sheet of the acquisition methods of embodiment of the present invention channel quality indication;

Figure 15 is the structural representation of the acquisition device of embodiment of the present invention channel quality indication;

Figure 16 is the schematic diagram of the acquisition methods of embodiment of the present invention channel quality indication;

Figure 17 is that the embodiment of the present invention does not have the analog result schematic diagram under the awgn channel of co-channel interference;

Figure 18 is that the embodiment of the present invention does not have the analog result schematic diagram under the PA3 channel of co-channel interference;

Figure 19 is that the embodiment of the present invention does not have the analog result schematic diagram under the PB3 channel of co-channel interference;

Figure 20 is that the embodiment of the present invention does not have the analog result schematic diagram under the VA30 channel of co-channel interference;

Figure 21 is that the embodiment of the present invention does not have the analog result schematic diagram under the VA120 channel of co-channel interference;

Figure 22 is that the embodiment of the present invention exists the analog result schematic diagram under the awgn channel of co-channel interference.

Embodiment

For technical problem, technical scheme and advantage that embodiments of the invention will be solved are clearer, be described in detail below in conjunction with the accompanying drawings and the specific embodiments.

Embodiments of the invention provide a kind of acquisition methods, device and user terminal of channel quality indication, can strengthen the robustness of CQI system, thereby improve the reliability of CQI feedback.

In TD-SCDMA system, UE, in obtaining the process of CQI, by obtaining the transmission situation of the HS-DSCH (high-speed down link sharing channel) of connection, and carries out necessary channel quality measurement to obtain CQI.The CQI that UE obtains is transferred to NodeB by HS-SICH (up-high speed is shared information channel), and NodeB can change coded system with the CQI obtaining in the transmitting procedure of next HS-DSCH, is illustrated in figure 1 the model schematic diagram of CQI algorithm.In addition, for dissimilar UE, there is the correspondence table of different channel quality and CQI.

In prior art, be mainly based on SIR(signal to interference ratio, signal-to-jamming ratio) estimated value or SNR(signal to noise ratio, signal noise ratio) estimated value is assessed channel quality, and then definite CQI.The present invention below will be introduced the process of these two kinds of algorithms:

one, SIR CQI algorithm

Be illustrated in figure 2 the schematic diagram of SIR CQI algorithm (determining the algorithm of CQI by SIR estimated value).SIR estimated value measures on each HS-DSCH time slot, and SIR CQI algorithm goes to search the correspondence table of default SIR and CQI according to SIR estimated value, obtain CQI value.

In TD-SCDMA system, the measuring process of SIR estimated value is as follows:

(1) definition SIR estimated value measuring process is input as initial channel estimation (Channel Estimation, CHE) result and denoising CHE result, the schematic diagram that Figure 3 shows that initial CHE result under VA120 channel, Fig. 4 is the schematic diagram of denoising CHE result under VA120 channel.Wherein, denoising CHE result is that initial CHE result is removed the result after noise.

(2) define initial CHE result Hini={hini (0), hini (1) ..., hini (len-1) } and denoising CHE result Hmic={hmic (0), hmic (1) ..., hmic (len-1) }.Wherein, len is the length of a channel estimation window.

(3) utilize following algorithm to calculate effective CHE number of path PathNum by Hmic:

Wherein, || represent delivery.The initial value that is PathNum is 0, from i=0 to i=len-1, right one by one | hmic (i) | ²judge, if | hmic (i) | ²> 0, and the value of PathNum adds one, and the PathNum value finally obtaining is effective CHE number of path.

(4) by formula (a) calculate Hini and Hmic power and:

$\left\{\begin{array}{c}\mathrm{PowerSumHini}=\underset{i=0}{\overset{\mathrm{len}-1}{\mathrm{\Σ}}}{\left|\mathrm{Hini}\left(i\right)\right|}^2\\ \mathrm{PowerSumHmic}=\underset{i=0}{\overset{\mathrm{len}-1}{\mathrm{\Σ}}}{\left|\mathrm{Hmic}\left(i\right)\right|}^2\end{array}\right.---\left(a\right)$

(5) by formula (b), calculate interference value interference:

interference＝((PowerSumHini-PowerSumHmic)/(len-PathNum))*len （b）

(6) by formula (c), calculate signal power SP:

SP＝PowerSumHmic-interference/len*PathNum （c）

(7) by formula (d), calculate SIR linear value SIR_linear, by formula (e), calculate SIR decibel value SIR:

SIR_linear＝SP/interference （d）

SIR＝10*log(SIR_linear/10) （e）

The correspondence table that can search default SIR and CQI according to the SIR decibel value calculating (the SIR estimated value that will obtain) afterwards, obtains CQI value.

According to above-mentioned SIR estimated value computational process, can find out, by calculate path power all in a channel estimation window and with all noise power and ratio can obtain SIR estimated value.SIR estimated value is not subject to the impact of modulating mode and SNR.

On wireless channel, not only there is white noise, also have interference signal simultaneously, these interference signals comprise multipath interference, ISI(Inter-Symbol Interference, intersymbol interference) and MAI(Multiple Access Interference, multiple access disturbs).Under AWGN (Additive White Gaussian Noise, additive white Gaussian noise) channel, the SIR estimated value obtaining is relatively good, and utilizes accurately estimated channel quality of this SIR estimated value.The CHE result of denoising under VA120 channel of take in Fig. 4 is example, it on main path, is useful signal, other path power is also not all useful signal, wherein some path power may become interference signal, this is because no matter JD (joint-detection) algorithm is based on MMSE(Minimum Mean Square Error, least mean-square error) still based on ZF(Zero-Forcing, ZF), equalizer all can not significantly reduce multipath effect.

Fig. 5 is the planisphere under awgn channel, Fig. 6 is the planisphere under VA120 channel, they have identical noise, but clearly the SIR of VA120 channel is poorer than the SIR on awgn channel, Fig. 5 and Fig. 6 have shown that the non-main path power of part has been subject to interference, and equalizer is difficult to eliminate these interference.

But in SIR CQI algorithm, SIR estimated value is according to all path power and calculates, due to all path power and the power that has comprised interference signal, therefore can be greater than actual subscriber signal power, the SIR estimated value obtaining is also just greater than SIR actual value, this phenomenon will bring very serious consequence: NodeB to send downstream signal with larger RTBS and RMF, this downstream signal but UE can not correctly decode, cause BLER(Block Error Ratio, bLock error rate) also will be very low by throughput very large and wireless communication system.Especially when noise very hour, utilize SIR estimated value that above-mentioned measuring process obtains by than large many of SIR actual value, cause BLER throughput poorer and wireless communication system less.

In order to prove above-mentioned phenomenon, the present invention has carried out a simulation process, and its configuration is as follows:

As shown in Figure 7, wherein lor/loc is useful signal spectrum density and the ratio of disturbance spectrum density to the analog result obtaining, from analog result, can find out, the deficiency of SIR CQI algorithm clearly: in strong jamming situation, the poor-performing of SIR CQI algorithm.

two, SNR CQI algorithm

Be illustrated in figure 8 the schematic diagram of SNR CQI algorithm (obtaining the algorithm of CQI by SNR estimated value).

Unique difference of SIR CQI algorithm and SNR CQI algorithm is for to determine CQI by different values of feedback.SIR CQI algorithm is used SIR estimated value, and SNR CQI algorithm is used SNR estimated value.As shown in Figure 2 and Figure 8, SIR estimated value obtains after CHE process, and SNR estimated value is to obtain before demodulation.

In TD-SCDMA system, the measuring process of SNR estimated value is as follows:

(1) before demodulation to incoming symbol delivery, making its power is 1, then gets its result S={s (0), s (1) ..., s (len-1) }, wherein len is symbol lengths, the average power of S is 1.

(2) carry out hard decision.In this step, on each symbol, carry out hard decision and obtain hard decision result the hard-decision method definition constellation point nearest apart from symbol is hard decision result, and for example QPSK hard-decision method is as follows:

$\hat{s}\left(i\right)=\left\{\begin{array}{cc}0.707+0.707j& \mathrm{if\; real}\left(s\left(i\right)\right)>0,\mathrm{imag}\left(s\left(i\right)\right)<0\\ 0.707-0.707j& \mathrm{if\; real}\left(s\left(i\right)\right)>0,\mathrm{imag}\left(s\left(i\right)\right)<0\\ -0.707+0.707j& \mathrm{if\; real}\left(s\left(i\right)\right)>0,\mathrm{imag}\left(s\left(i\right)\right)<0\\ -0.707-0.707j& \mathrm{if\; real}\left(s\left(i\right)\right)>0,\mathrm{imag}\left(s\left(i\right)\right)<0\end{array}\right.$

The hard-decision method of 16QAM and 64QAM is similar to QSPK.

(3) adopt formula (f) calculating noise power NP:

$\mathrm{NP}=\underset{i=0}{\overset{\mathrm{len}-1}{\mathrm{\&Sigma;}}}\left({|s\left(i\right)-\hat{s}\left(i\right)|}^2\right)/\mathrm{len}---\left(f\right)$

(4) utilize formula (g) and (h) calculate SNR linear value SNR_linear and SNR decibel value SNR:

SNR_linear=1/NP (because data power=1) (g)

SNR＝10*log(SNR_linear) （h）

The correspondence table that can search default SNR and CQI according to the SNR decibel value calculating (the SNR estimated value that will obtain) afterwards, obtains CQI value.

From the computational process of above-mentioned SNR estimated value, can find out, SNR CQI algorithm is very sensitive to SNR and modulating mode, when the actual value of SNR is lower or during high order modulation (16QAM and 64QAM), hard decision is easy to make mistakes, cause the SNR estimated value can be large compared with SNR actual value.

Figure 9 shows that under QPSK pattern when SNR actual value is higher, the symbol constellation schematic diagram before demodulation, in this case, the hard decision of each symbol is correct, so SNR estimated value is accurate.Figure 10 shows that under QPSK pattern when SNR actual value is lower, symbol constellation schematic diagram before demodulation, in this case, some symbol can enter other quadrant, the hard decision mistake of some symbol will be caused, and mistaken verdict meeting makes noise power estimated value lower than actual value, so the SNR estimated value producing also can be higher than SNR actual value.

Figure 11 shows that under QPSK pattern uses different SNR that the analog result of the SNR estimated value obtaining is set.Figure 12 shows that under 16QAM pattern uses different SNR that the analog result of the SNR estimated value obtaining is set.Figure 13 shows that under 64QAM pattern uses different SNR that the analog result of the SNR estimated value obtaining is set.By these analog results, can find out, for different modulating modes, when SNR actual value is during higher than a threshold value, the corresponding SNR estimated value obtaining can be more accurate; If but SNR actual value during lower than this threshold value, the corresponding SNR estimated value obtaining can be not too accurate.And there is a lower limit, even if SNR actual value is very little, but the SNR estimated value obtaining can not be less than this lower limit yet.For 16QAM and 64QAM pattern, the threshold value that it is corresponding and lower limit are all greater than threshold value corresponding to QSPK pattern and lower limit.

From above-mentioned analog result with analyze and can find out, the weak point of SNR CQI algorithm clearly: under low SNR environment, the SNR estimated value by above-mentioned SNR CQI algorithm measurement is by than large many of SIR actual value.

In sum, SIR CQI algorithm is more responsive to interference ratio, and under strong jamming condition, the SIR estimated value obtaining wants large compared with SNR actual value; SNR CQI algorithm is more responsive to SNR actual value, and when SNR actual value is lower, the SIR estimated value obtaining wants large compared with SNR actual value.

In order to address the above problem, the invention provides a kind of acquisition methods, device and user terminal of channel quality indication, SNR estimated value and SIR estimated value based in TD-SCDMA system obtain CQI.As shown in figure 14, the acquisition methods of channel quality indication of the present invention comprises:

Step 101: calculate respectively SIR estimated value and SNR estimated value;

Step 102: determine final estimated value according to the SIR estimated value calculating and SNR estimated value;

Step 103: utilize described final estimated value to determine channel quality indication.

Further, another embodiment of the present invention kind, comprises on the basis of above-mentioned steps 101～103, and the SIR estimated value that described basis calculates and SNR estimated value determine that final estimated value comprises:

According to the difference of described SIR estimated value and SNR estimated value, determine described final estimated value.

Further, another embodiment of the present invention kind, comprises on the basis of above-mentioned steps 101～103, and the described difference according to described SIR estimated value and SNR estimated value determines that described final estimated value comprises:

When the difference of described SIR estimated value and SNR estimated value is less than predetermined threshold value, determine that final estimated value is the mean value of described SIR estimated value and SNR estimated value;

When the difference of described SIR estimated value and SNR estimated value is not less than predetermined threshold value, determine that final estimated value is the smaller value of described SIR estimated value and SNR estimated value.

Further, another embodiment of the present invention kind, comprises on the basis of above-mentioned steps 101～103, describedly utilizes described final estimated value to determine that CQI comprises:

Utilize described final estimated value to search default final estimated value and the correspondence table between CQI, determine the CQI corresponding with described final estimated value.

The embodiment of the present invention is determined final estimated value in conjunction with SIR estimated value and SNR estimated value, and utilizes final estimated value to determine channel quality indication.Technical scheme of the present invention is carried out under the prerequisite of large change TD-SCDMA receiving terminal not needing, and can accurately obtain CQI, and then improves the reliability of CQI feedback.

The embodiment of the present invention also provides a kind of acquisition device of channel quality indication, and as shown in figure 15, the present embodiment comprises:

Computing module 20, for difference calculated sir SIR estimated value and signal noise ratio SNR estimated value;

Processing module 21, for determining final estimated value according to the SIR estimated value and the SNR estimated value that calculate;

Determination module 22, for utilizing described final estimated value to determine CQI.

Further, in such scheme, described processing module 21 is for determining described final estimated value according to the difference of described SIR estimated value and SNR estimated value.

Further, in such scheme, when described processing module 21 is less than predetermined threshold value specifically for the difference when described SIR estimated value and SNR estimated value, determine that final estimated value is the mean value of described SIR estimated value and SNR estimated value; When the difference of described SIR estimated value and SNR estimated value is not less than predetermined threshold value, determine that final estimated value is the smaller value of described SIR estimated value and SNR estimated value.

Further, in such scheme, described determination module 22, specifically for utilizing described final estimated value to search default final estimated value and the correspondence table between CQI, is determined the CQI corresponding with described final estimated value.

Further, in such scheme, described computing module 20 comprises:

The first calculating sub module, be used for utilizing denoising channel estimating CHE result to calculate effective CHE number of path, calculate respectively initial CHE result power and and the power of denoising CHE result and, and according to the CHE number of path obtaining, initial CHE result power and and power and definite interference value interference and the signal power SP of denoising CHE result, by following formula, calculate SIR estimated value SIR:

SIR_linear＝SP/interference

SIR＝10*log(SIR_linear/10)；

The second calculating sub module, for before demodulation to incoming symbol delivery, and on each symbol, carry out hard decision and obtain hard decision result, according to hard decision result calculating noise power NP, by following formula, calculate SNR estimated value SNR:

SNR_linear＝1/NP

SNR＝10*log(SNR_linear)。

The embodiment of the present invention is determined final estimated value in conjunction with SIR estimated value and SNR estimated value, and utilizes final estimated value to determine channel quality indication.Technical scheme of the present invention is carried out under the prerequisite of large change TD-SCDMA receiving terminal not needing, and can accurately obtain CQI, and then improves the reliability of CQI feedback.

The embodiment of the present invention also provides a kind of user terminal, comprises the acquisition device of channel quality indication as above.

Acquisition methods and device below in conjunction with 16～22 pairs of channel quality indications of the present invention of accompanying drawing describe in detail:

Known by above-mentioned analysis of the present invention, traditional SIR CQI algorithm and SNR CQI algorithm have its shortcoming separately:

(1) SIR CQI algorithm is more responsive to interference ratio, can not well overcome strongly disturbing situation.

(2) SNR CQI algorithm is more responsive to SNR actual value, can not well overcome the situation of low SNR actual value.

The present invention, by determining last estimated value in conjunction with SNR estimated value and SIR estimated value, can avoid the problem of above-mentioned existence.

Technical scheme of the present invention avoids using abnormal SNR estimated value and SIR estimated value to remove to obtain channel quality.Known according to above-mentioned analysis, when SIR estimated value and SNR estimated value are when undesired, they are conventionally high than actual value.The present invention is SNR estimated value and SIR estimated value first relatively, if the difference of SIR estimated value and SNR estimated value is greater than default threshold value, in SIR estimated value and SNR estimated value, larger one can be considered as abnormal estimated value, with another one estimated value, obtains channel quality; If the difference of SIR estimated value and SNR estimated value is less than this threshold value, SIR estimated value and SNR estimated value all can be regarded as normal threshold value, can utilize the mean value of SNR estimated value and SIR estimated value to obtain channel quality.

Figure 16 shows that the schematic diagram of the acquisition methods of channel quality indication of the present invention, first carry out the measuring process of SIR estimated value and SNR estimated value, obtain SNR estimated value SNR and SIR estimated value SIR, the measuring process of SIR estimated value and SNR estimated value is identical with measuring process of the prior art, does not repeat them here.

Afterwards, definition threshold value α, utilizes following algorithm to obtain final estimated value FMV in conjunction with SNR estimated value SNR and SIR estimated value SIR:

if |SNR-SIR|＜α

FMV＝average(SNR,SIR)

else

FMV＝min(SNR,SIR)

Wherein average (.) represents to average, and min (.) represents to obtain minimum value, | .| represents delivery.

Wherein, threshold value α can obtain by simulation, and when α=0, FMV is the minimum value in SNR estimated value and SIR estimated value.Known by testing, preferably threshold value α is 3dB.

Finally, the correspondence table that the final estimated value that use obtains removes to search default estimated value and CQI, can obtain the CQI that includes the fast size of transmission and modulation format.UE feeds back to NodeB by the CQI of acquisition, can improve the throughput of wireless communication system.

The result of the SIR CQI algorithm under some situations in TD-SCDMA system, SNR CQI algorithm and New CQI algorithm of the present invention (being the acquisition methods of new CQI provided by the invention) is carried out to simulation and comparison below, comprising co-channel interference situation with without co-channel interference situation.

As shown in the table is analog configuration without co-channel interference:

In this case because there is no co-channel interference, so for subscriber signal, only exist multipath to disturb and noise effect.In above-mentioned Figure 17～Figure 21, the throughput that the longitudinal axis is wireless communication system, transverse axis is lor/loc.From Figure 17～Figure 21, can find out, the throughput of system that CQI acquisition methods provided by the invention obtains will equal or approach the maximum of the throughput of system that SNR CQI algorithm and SIR CQI algorithm obtain.

As shown in the table is the analog configuration of co-channel interference:

Figure 22 is depicted as the analog result under the awgn channel that has co-channel interference.From the analog result shown in Figure 22, can find out, the throughput of system that the acquisition methods of CQI provided by the invention obtains will equal the maximum of the throughput of system obtaining of SNR CQI algorithm and SIR CQI algorithm.

In addition, at current TD-SCDMA receiving terminal, SNR estimated value and SIR estimated value calculate in measuring process, so for the present invention, only have at most 2 comparisons and 1 extra operation, simple to operate, do not need current TD-SCDMA receiving terminal to improve.New CQI algorithm provided by the invention can overcome the situation of strong jamming and low SNR, can obtain higher throughput of system and better performance, and only brings very little additional complexity and can not bring risk.

Many functional parts described in this specification are all called as module, to emphasize more especially the independence of its implementation.

In the embodiment of the present invention, module can realize with software, to carried out by various types of processors.For instance, the executable code module of a sign can comprise one or more physics or the logical block of computer instruction, and for instance, it can be built as object, process or function.However, the executable code of institute's identification module is without being physically located in together, but can comprise and be stored in different different instructions physically, while combining in these command logics, and its composition module and realize the regulation object of this module.

In fact, executable code module can be individual instructions or many instructions, and even can be distributed on a plurality of different code segments, is distributed in the middle of distinct program, and crosses over a plurality of memory devices distributions.Similarly, operating data can be identified in module, and can realize and be organized in the data structure of any suitable type according to any suitable form.Described operating data can be used as individual data collection and is collected, or can be distributed on diverse location and (be included in different storage device), and can only as electronic signal, be present on system or network at least in part.

When module can utilize software to realize, consider the level of existing hardware technique, so module that can realize with software, in the situation that not considering cost, those skilled in the art can build corresponding hardware circuit and realize corresponding function, and described hardware circuit comprises conventional ultra-large integrated (VLSI) circuit or gate array and the existing semiconductor such as logic chip, transistor or other discrete element.Module can also be used programmable hardware device, realizations such as field programmable gate array, programmable logic array, programmable logic device.

In each embodiment of the method for the present invention; the sequence number of described each step can not be for limiting the sequencing of each step; for those of ordinary skills, do not paying under the prerequisite of creative work, the priority of each step is changed also within protection scope of the present invention.

The above is the preferred embodiment of the present invention; it should be pointed out that for those skilled in the art, do not departing under the prerequisite of principle of the present invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (11)

1. an acquisition methods for channel quality indication, is characterized in that, comprising:

Difference calculated sir SIR estimated value and signal noise ratio SNR estimated value;

According to the SIR estimated value calculating and SNR estimated value, determine final estimated value;

Utilize described final estimated value to determine channel quality indicator (CQI).

2. the acquisition methods of channel quality indication according to claim 1, is characterized in that, the SIR estimated value that described basis calculates and SNR estimated value determine that final estimated value comprises:

According to the difference of described SIR estimated value and SNR estimated value, determine described final estimated value.

3. the acquisition methods of channel quality indication according to claim 2, is characterized in that, the described difference according to described SIR estimated value and SNR estimated value determines that described final estimated value comprises:

When the difference of described SIR estimated value and SNR estimated value is less than predetermined threshold value, determine that final estimated value is the mean value of described SIR estimated value and SNR estimated value;

When the difference of described SIR estimated value and SNR estimated value is not less than predetermined threshold value, determine that final estimated value is the smaller value of described SIR estimated value and SNR estimated value.

4. the acquisition methods of channel quality according to claim 1 indication, is characterized in that, describedly utilizes described final estimated value to determine that CQI comprises:

Utilize described final estimated value to search default final estimated value and the correspondence table between CQI, determine the CQI corresponding with described final estimated value.

5. the acquisition methods of channel quality according to claim 1 indication, is characterized in that, describedly calculates respectively SIR estimated value and SNR estimated value comprises:

(1) by step a～c, calculate SIR estimated value:

Step a: utilize denoising channel estimating CHE result to calculate effective CHE number of path;

Step b: calculate respectively initial CHE result power and and the power of denoising CHE result and, and according to the CHE number of path obtaining, initial CHE result power and and power and definite interference value interference and the signal power SP of denoising CHE result;

Step c: calculate SIR estimated value SIR by following formula:

SIR_linear＝SP/interference

SIR＝10*log(SIR_linear/10)；

(2) by steps d～e, calculate SNR estimated value:

Steps d: to incoming symbol delivery, and carried out hard decision and obtained hard decision result on each symbol before demodulation;

Step e: according to hard decision result calculating noise power NP, calculate SNR estimated value SNR by following formula:

SNR_linear＝1/NP

SNR＝10*log(SNR_linear)。

6. an acquisition device for channel quality indication, is characterized in that, comprising:

Computing module, for difference calculated sir SIR estimated value and signal noise ratio SNR estimated value;

Processing module, for determining final estimated value according to the SIR estimated value and the SNR estimated value that calculate;

Determination module, for utilizing described final estimated value to determine channel quality indicator (CQI).

7. the acquisition device of channel quality indication according to claim 6, is characterized in that,

Described processing module is for determining described final estimated value according to the difference of described SIR estimated value and SNR estimated value.

8. the acquisition device of channel quality indication according to claim 7, is characterized in that,

When described processing module is less than predetermined threshold value specifically for the difference when described SIR estimated value and SNR estimated value, determine that final estimated value is the mean value of described SIR estimated value and SNR estimated value; When the difference of described SIR estimated value and SNR estimated value is not less than predetermined threshold value, determine that final estimated value is the smaller value of described SIR estimated value and SNR estimated value.

9. the acquisition device of channel quality indication according to claim 6, is characterized in that,

Described determination module, specifically for utilizing described final estimated value to search default final estimated value and the correspondence table between CQI, is determined the CQI corresponding with described final estimated value.

10. the acquisition device of channel quality indication according to claim 6, is characterized in that, described computing module comprises:

The first calculating sub module, be used for utilizing denoising channel estimating CHE result to calculate effective CHE number of path, calculate respectively initial CHE result power and and the power of denoising CHE result and, and according to the CHE number of path obtaining, initial CHE result power and and power and definite interference value interference and the signal power SP of denoising CHE result, by following formula, calculate SIR estimated value SIR:

SIR_linear＝SP/interference

SIR＝10*log(SIR_linear/10)；

The second calculating sub module, for before demodulation to incoming symbol delivery, and on each symbol, carry out hard decision and obtain hard decision result, according to hard decision result calculating noise power NP, by following formula, calculate SNR estimated value SNR:

SNR_linear＝1/NP

SNR＝10*log(SNR_linear)。

11. 1 kinds of user terminals, is characterized in that, comprise the acquisition device of the channel quality indication as described in any one in claim 6-10.