CN101047471A

CN101047471A - Feedback control method and system

Info

Publication number: CN101047471A
Application number: CN 200610081076
Authority: CN
Inventors: 刘晟; 杜颖钢
Original assignee: Huawei Technologies Co Ltd
Current assignee: XFusion Digital Technologies Co Ltd
Priority date: 2006-05-23
Filing date: 2006-05-23
Publication date: 2007-10-03
Anticipated expiration: 2026-05-23
Also published as: CN101047471B

Abstract

A method for controlling feedback includes the first technical scheme as optimizing existed differential feedback control plan to utilize gradual change character of channel to provide detection mechanism for feedback ACQI and the second technical scheme as adding CRC verification on feedback ACQI information at receiving end then detecting whether received ACQI is correct or not by emitting end according to CRC verification code.

Description

A kind of feedback and system

Technical field

The present invention relates to wireless communication technology, in particularly a kind of adaptive coding modulation, the feedback and the system of the absolute magnitude of modulation and coded system index.

Background technology

Adaptive coding modulation is meant that receiving terminal feeds back to transmitting terminal with the information of measuring such as channel quality by feedback channel, modes such as chnnel coding that Information Selection such as the channel quality that transmitting terminal provides according to receiving terminal are suitable and modulation, typically as type of coding, code rate, modulation system (QPSK/16QAM etc.), thereby reach the self adaptation of channel and maximize the purpose of transmission rate.Wherein, the control signaling consumption that brings for the information such as channel quality that reduce receiving terminal feedback, general way is typical MCS (the Modulation and Coding Scheme that transmitting terminal is supported, modulation and coded system) make a concordance list and be kept at transmitting terminal and receiving terminal simultaneously, receiving terminal is according to the performance requirement of own receiver, having pre-determined it requires down the needed channel quality of each MCS of reception (typically with SINR (Signal to Interference and Noise Ratio in certain receptivity (as the error rate etc.), Signal Interference and Noise Ratio) characterizes), like this, receiving terminal just can be judged the MCS that it can receive according to the channel quality of actual measurement, and the index of this MCS in described MCS concordance list (CQI, the indication of Channel QualityIndicator channel quality) fed back to transmitting terminal.

A MCS mapping table commonly used is as shown in table 1, and the MCS mapping table is kept at transmitting terminal and receiving terminal simultaneously.Receiving terminal is calculated SINR according to channel situation, and feedback MCS index gets final product.

The MCS index	Spectrum efficiency (Bps/Hz)	Modulation	Encoding rate	Bit is represented
The MCS index	Spectrum efficiency (Bps/Hz)	Modulation	Encoding rate	Bit is represented	6	3	16QAM	3/4	100
5	2	16QAM	1/2	110	6	3	16QAM	3/4	100
5	2	16QAM	1/2	110	4	1.5	QPSK	3/4	010
3	1	QPSK	1/2	011	4	1.5	QPSK	3/4	010
3	1	QPSK	1/2	011	2	0.5	QPSK	1/4	001

Not 1 (not launching)

0

-

000

Table 1:MCS mapping table

MIMO (Multi-Input Multi-Output, multiple-input and multiple-output) application of technology in wireless communication system more and more comes into one's own, no matter be that MIMO has its irreplaceable superiority from angle that increases power system capacity or the angle of improving systematic function.In the MIMO technology, in order more effectively to transmit data, need control the data rate of transmitting terminal, this just needs transmitting terminal to know some information of channel by feedback, dynamically adjusts data rate, even adjusts the emission rate of each transmitting antenna.

Existing space division multiplexing technological model ground based on MIMO can be divided into following two kinds of structures:

1, single codeword SCW (Single Code Word) pattern

As shown in Figure 1, for SCW, data flow to be sent at first through chnnel coding, interweave and operation such as planisphere mapping, go out (number that M is transmitting antenna) through different transmission antennas transmit respectively for the data flow of M road phase same rate along separate routes then.Receiving terminal calculates the average SINR of all channels, looks into the average MCS of MCS concordance list feedback.At transmitting terminal, as shown in Figure 1, data flow to be launched adopts unified channel encoder, RM (Rate Matching, rate-matched) mode and modulation system, then all data is distributed to each transmitting antenna, launches after handling accordingly.According to the difference of the multi-access mode that system adopted, channel code or channel resources such as frequency or time that the data occupancy of this M transmitting antenna is identical

2, many code words MCW (Multiple Code Word) pattern

As shown in Figure 2, for MCW, data flow to be sent is the data flow of M road and M the corresponding different rates of transmitting antenna at first along separate routes, then respectively through chnnel coding independently, interweave and operation such as planisphere mapping, go out by corresponding transmission antennas transmit respectively at last.Similarly, difference according to the multi-access mode that system adopted, channel code or channel resources such as frequency or time that the data occupancy of this M transmitting antenna is identical, for example, to cdma system, M transmitting antenna uses identical channel code, and to the OFDMA system, M transmitting antenna uses one group of identical subcarrier etc.

Adopt the OFDM technology to send lot of data simultaneously by different subcarriers, so OFDM is a mainstream technology of next generation communication system, also just because sub-carrier number is more, therefore generally can not control the data rate on each subcarrier, way commonly used is the plurality of adjacent subcarrier to be merged become a subband, the unified scheduling of subcarrier that this subband comprised is handled, receiving terminal calculates the average effective SINR of this subband, tables look-up then to obtain corresponding M CS (Modulation ﹠amp; Coding Scheme, modulation and coded system) index, feed back to transmitting terminal, look into the MCS concordance list is counter by transmitting terminal, can obtain this subband corresponding M CS, that is to say,, can regard the MCS of this subband scheduling as common MCS scheduling when we regard this subband as an integral body.At transmitting terminal, give the MCS of this allocation of subbands correspondence according to MCS index that feeds back and corresponding channel situation.

The MIMO technology usually again and adaptive coding and modulating (AMC) technology combine, in adaptive coding and modulating scheme based on space division multiplexing technology mimo system, in the SCW pattern since each day wire rate identical, therefore receiving terminal only need feed back a total CQI information, adaptive coding and modulating under this and the single channel antenna is similar, but, in the MCW pattern, different antennas adopts different coded modulation schemes, speed is all inequality, so receiving terminal need feed back corresponding C QI information respectively at each transmitting antenna.Because the MCW pattern is carried out dynamic rate controlled at every antenna, therefore the MCW pattern has than SCW pattern more performance, but, because the MCW pattern need be fed back different CQI information respectively at each transmitting antenna, therefore the MCW pattern needs more feedback control signaling expense, and required feedback control information amount is M a times of single-antenna case.In the prior art, the key issue that the MIMO Technology Need of MCW pattern is solved is how to reduce the feedback quantity of CQI, thus the expense of the feedback control signaling that reduces.

In mimo system, when Transmission Time Interval TTI length during less than the correlated time of channel, the variation difference of channel fading is then less between the adjacent TTI of the same antenna, therefore the CQI to every transmit antennas feeds back, the differential feedback mode that adopts CQI absolute magnitude ACQI (Absolute CQI, absolute CQI) and CQI relative quantity RCQI (Relative CQI, CQI relatively) to combine, wherein, ACQI can adopt the channel (being different backward channels) that separates to transmit with RCQI.

Transmit being mapped on the physical channel after ACQI employing block encoding or the convolutional encoding, wherein, the ACQI of every transmit antennas is not each TTI continuous feedback, but feeds back with certain feedback cycle (an ACQI feedback cycle comprises more than one TTI).For example, the ACQI feedback cycle of each antenna TTI that staggers successively, promptly in the ACQI feedback cycle to certain transmitting antenna, transmit the ACQI that this antenna ACQI other TTI in addition can be used to transmit other antenna successively, if the TTI number that ACQI feedback cycle comprises equals antenna number M, ACQI with M=4 is transmitted as example, can be the 1st, 5,9... individual TTI transmits the ACQI of the 1st antenna, the 2nd, 6,10... individual TTI transmits the ACQI of the 2nd antenna, the 3rd, 7,11... individual TTI transmits the ACQI of the 3rd antenna, the 4th, 8,12... individual TTI transmits the ACQI of the 4th antenna.If the TTI number that ACQI feedback cycle comprises is greater than antenna number M, then in remaining TTI, adopt discontinuous transmission (DTX, DiscontinuousTransmission) mode, feedback signal not in corresponding TTI, for example, M=4, the ACQI feedback cycle comprises 5 TTI, and not feedback signal is arranged among then per 5 TTI in the TTI.Transmit timing pattern (Timing Pattern) according to the definite corresponding ACQI of each transmitting antenna of above-mentioned rule is pre-configured, so receiving-transmitting sides can correctly send and receive the ACQI of each transmitting antenna according to this timing pattern.

In the ACQI feedback cycle to certain transmitting antenna, transmit this antenna ACQI other TTI in addition and need transmit RCQI, promptly in the TTI of the ACQI of given this transmitting antenna of transmission of ACQI transmit timing pattern (Timing Pattern), do not transmit the RCQI value of this transmitting antenna, RCQI adopts the DTX mode to transmit, 1 of RCQI employing or 2 bits represent that RCQI=0 shows that adjacent next TTI adopts and a last CQI that TTI is identical.

At OFDM (Orthogonal Frequency DivisionMultiplexing, OFDM) similar techniques is also arranged in the system, when TTI length during less than the correlated time of channel, the variation difference of channel fading is less between the adjacent TTI of same subband, therefore the CQI to each subband transmits, the feedback system that adopts CQI absolute magnitude ACQI to combine with CQI relative quantity RCQI, wherein, ACQI can adopt the channel (being different backward channels) that separates to transmit with RCQI, in the MIMO-OFDM system, also be suitable for same principle.

Above-mentioned differential feedback method has reduced feedback quantity, but brought such problem simultaneously, if the ACQI that transmitting terminal receives makes mistakes, will be in the quite a while (the longest reach whole ACQI feedback cycle) influence the CQI value that transmitting terminal is determined, and and then influence throughput of transmissions and efficiency of transmission, the amplitude of makeing mistakes big more then the influence outstanding more.

Summary of the invention

The invention provides in a kind of adaptive coding modulation, the feedback and the system of the modulation and the absolute magnitude of coded system index are to solve the problem of how ACQI of the feedback in the differential feedback mode being carried out the reliability detection.

For realizing above-mentioned technical conceive, the invention provides following technical scheme:

A kind of feedback, receiving terminal periodically will feed back to transmitting terminal with the absolute magnitude ACQI of corresponding modulation of receptivity and coded system index CQI, when transmitting terminal receives described ACQI at every turn, carry out following step:

The ACQI that A1, calculating receive deducts modulation and the coded system index CQI of an adjacent last Transmission Time Interval TTI _OldThe absolute value of difference;

A2, judge described absolute value,, otherwise judge that this ACQI that receives makes mistakes if judge that then the ACQI that receives is reliable whether smaller or equal to first threshold value of setting.

Also comprise in the described steps A 2, transmitting terminal is at described absolute value during greater than described first threshold value, judge once more whether current feedback signal signal to noise ratio exceeds second threshold value of setting,, otherwise judge that this ACQI that receives makes mistakes if judge that again the ACQI that receives is reliable.

Also comprise in the described steps A 2:

When transmitting terminal judges that the ACQI that receives is reliable, with the CQI of this ACQI as adjacent next TTI _New

When transmitting terminal judges that the ACQI that receives makes mistakes, determine described CQI according to one of following method _New:

Make described CQI _NewEqual described CQI _Old

Make described CQI _NewEqual to add described CQI after described difference multiply by the setting weighted value _Old, described weighted value is according to emulated data value between 0 to 1;

Determine a fixed compensation value according to emulated data in advance, when described difference greater than zero the time, make described CQI _NewEqual described CQI _OldAdd the above fixed compensation value; When described difference less than zero the time, make described CQI _NewEqual described CQI _OldDeduct described fixed compensation value;

Determine offset according to emulated data in advance in different feedback signal signal to noise ratio correspondences, when described difference greater than zero the time, make described CQI _NewEqual described CQI _OldAdd the offset of current feedback signal signal to noise ratio correspondence; When described difference less than zero the time, make described CQI _NewEqual described CQI _OldDeduct the offset of current feedback signal signal to noise ratio correspondence;

Determine with the feedback signal signal to noise ratio to be the penalty function of independent variable according to emulated data in advance, when described difference greater than zero the time, make described CQI _NewEqual described CQI _OldAdd the functional value of current feedback signal signal to noise ratio correspondence; When described difference less than zero the time, make described CQI _NewEqual described CQI _OldDeduct the functional value of current feedback signal signal to noise ratio correspondence.

Described feedback signal is meant the feedback signal of carrying described ACQI or other feedback informations.

The control system that realizes above-mentioned control method comprises: first feedback control module and second feedback control module that is positioned at the data transmission end that are positioned at data receiver, described first feedback control module periodically will feed back to described second feedback control module with the absolute magnitude ACQI of corresponding modulation of receptivity and coded system index CQI, wherein, comprise detecting unit in described second feedback control module;

This detecting unit calculates modulation and coded system index CQI that the ACQI that receives deducts an adjacent last Transmission Time Interval TTI at every turn when receiving described ACQI _OldThe absolute value of difference, whether judge described absolute value again smaller or equal to first threshold value of setting, if judge that then the ACQI that receives is reliable, otherwise judge that this ACQI that receives makes mistakes; Perhaps

This detecting unit calculates modulation and coded system index CQI that the ACQI that receives deducts an adjacent last Transmission Time Interval TTI at every turn when receiving described ACQI _OldThe absolute value of difference, whether judge earlier described absolute value smaller or equal to first threshold value of setting, if otherwise directly the ACQI that receives of judgement is reliable; Otherwise whether the signal to noise ratio snr of judging current feedback signal again exceeds second threshold value of setting, if judge that then the ACQI that receives is reliable, otherwise judges that this ACQI that receives makes mistakes.

Also comprise determining unit in described second feedback control module, connect described detecting unit;

When the ACQI that receives is reliable, this ACQI is defined as the CQI of adjacent next TTI _New

When the ACQI that receives makes mistakes, determine described CQI according to one of preceding method _New

The present invention also provides a kind of another kind of feedback of realizing above-mentioned technical conceive, comprises the steps:

B1, receiving terminal are periodically to transmitting terminal feedback and the corresponding modulation of receptivity and the absolute magnitude ACQI of coded system index CQI and the CRC check sign indicating number of this ACQI;

When B2, transmitting terminal receive described ACQI at every turn, behind the described ACQI of the correct verification of corresponding CRC check sign indicating number, judge that the ACQI that receives is reliable, otherwise judge that this ACQI that receives makes mistakes.

Among the described step B2, when transmitting terminal judges that the ACQI that receives is reliable, with the CQI of this ACQI as adjacent next TTI _New

Make described CQI _NewEqual described CQI _Old

Determine the offset of different feedback signal signal to noise ratio correspondences in advance according to emulated data, when described difference greater than zero the time, make described CQI _NewEqual described CQI _OldAdd the offset of current feedback signal signal to noise ratio correspondence; When described difference less than zero the time, make described CQI _NewEqual described CQI _OldDeduct the offset of current feedback signal signal to noise ratio correspondence;

Realize a kind of feedback control system of said method, comprise first feedback control module that is positioned at data receiver and second feedback control module that is positioned at the data transmission end, wherein:

Described first feedback control module is periodically to the absolute modulation of described second feedback control module feedback receptivity correspondence and the CRC check sign indicating number of coded system index ACQI and correspondence;

Comprise detecting unit in described second feedback control module, when this detecting unit receives described ACQI at every turn, behind the described ACQI of the correct verification of CRC check sign indicating number according to correspondence, judge that the ACQI that receives is reliable, otherwise judge that this ACQI that receives makes mistakes.

Beneficial effect of the present invention is as follows:

First kind of technical scheme provided by the invention optimized existing differential feedback controlling schemes, utilize the roll-off characteristic of channel to provide testing mechanism for the ACQI that feeds back, improved the reliability of using ACQI, reduced and used the possibility of ACQI of makeing mistakes, thereby reduced ACQI and made mistakes the influence of system transmissions throughput and efficiency of transmission;

Second kind of technical scheme provided by the invention increased the feedback of CRC check on the ACQI information of feedback by receiving terminal, whether transmitting terminal detects the ACQI that receives according to the CRC check sign indicating number correct, improved the reliability of using ACQI, reduced and used the possibility of ACQI of makeing mistakes, thereby reduced ACQI and made mistakes the influence of system transmissions throughput and efficiency of transmission;

In above-mentioned two kinds of technical schemes, detect ACQI when makeing mistakes, making full use of the gradually changeable correction ACQI of channel, effectively improving feedback quality;

Technical scheme of the present invention has effectively remedied the deficiency of existing differential feedback controlling schemes, with prior art favorable compatibility is arranged.

Description of drawings

Fig. 1 is a single codeword pattern MIMO structure;

Many patterns of code words of Fig. 2 MIMO structure;

Fig. 3 is the schematic flow sheet of embodiment one described feedback;

Fig. 4 is the schematic flow sheet of embodiment two described feedbacks;

Fig. 5 is for realizing a kind of feedback structure schematic diagram of embodiment one, embodiment two and embodiment three described feedbacks;

Fig. 6 is the schematic flow sheet of embodiment three described feedbacks.

Embodiment

The problem of makeing mistakes that first kind of technical scheme provided by the invention may occur when the subband feedback ACQI of the MIMO of MCW pattern or OFDM at existing differential feedback control method, because factors such as experience channel fading and interference when feedback channel transmits in the space, sometimes can not correctly receive the ACQI value at transmitting terminal, so need introduce the ACQI testing mechanism at transmitting terminal, this testing mechanism effectively utilizes the roll-off characteristic of channel that the ACQI that receives is detected, if receive ACQI by detecting, illustrate that then the ACQI that receives is reliable, can be applied as this ACQI the CQI of adjacent next TTI _NewOtherwise, when the ACQI that receives not when detecting, illustrate that the ACQI that receives makes mistakes, at the situation of makeing mistakes, the present invention still utilizes the roll-off characteristic of channel to provide solution, below with specific embodiment and be described with reference to the accompanying drawings.

Embodiment one

As shown in Figure 3, receiving terminal periodically will feed back to transmitting terminal with the absolute magnitude ACQI of corresponding modulation of receptivity and coded system index CQI, and whether when transmitting terminal receives described ACQI at every turn, it is reliable to utilize following step to detect ACQI:

The ACQI that S101, calculating receive deducts modulation and the coded system index CQI of an adjacent last Transmission Time Interval TTI _OldThe absolute value of difference;

S102, judge described absolute value whether smaller or equal to first threshold value of setting, if then judge the reliable and execution in step S103 of the ACQI that receives; Otherwise judge that this ACQI that receives makes mistakes and execution in step S104;

Here, first threshold value utilizes empirical data to determine according to the gradually changeable of channel.

S103, directly with the CQI of this ACQI as adjacent next TTI _New

S104, redefine the CQI of adjacent next TTI according to one of following method _New:

Method one,

Make ACQI _New=CQI _Old, promptly abandon the ACQI of reception fully, but with the CQI of an adjacent last TTI _OldCQI as adjacent next TTI _New

Method two,

Make ACQI _New=CQI _Old+ α * (ACQI-CQI _Old), α is the weighted value of determining between 0 to 1 according to emulated data in advance here, satisfies 0＜α＜1, promptly utilizes ACQI and CQI _OldBetween difference the ACQI that receives is modified to ACQI _New, then with this ACQI _NewCQI as adjacent next TTI _New

Here, consider the gradually changeable of channel, the ACQI that feeds back has reflected the trend of channel conversion at least, but changing value is excessive and the amplitude that departs from right value within the specific limits, therefore correspondingly by suitable weighted factor, this variation is tapered in the scope of normal variation.So, can simulate deviation possible under the different situations, determine the amplitude of deviation according to emulated data, correspondence obtains rational α and rectifies a deviation.

Method three,

Make ACQI _New=CQI _Old+ β * Ω, β=sign (ACQI-CQI here _Old), sign is a sign function, as (ACQI-CQI _Old) greater than 0 o'clock, β got+1, as (ACQI-CQI _Old) less than 0 o'clock, β got-1, β has reflected the most probable change direction of channel in fact.Ω is for to determine a fixed compensation value according to emulated data, its expression when ACQI is insecure, utilize given Ω will and CQI _OldDetermine ACQI _New, then with this ACQI _NewCQI as adjacent next TTI _New

The gradually changeable of the channel quality that this method is utilized is according to ACQI-CQI _OldDifference judge the possible change direction of channel, and then according to change direction with CQI _OldCompensate a reasonable value.Can carry out emulation to a plurality of representative channel, obtain taking place the changing value of CQI under the various situations of error of transmission, getting a typical changing value after taking all factors into consideration is offset, such as the average of asking the CQI changing value under the various situations, makes being Ω.

Method four,

The feedback loop reference signal signal to noise ratio is determined the offset of different feedback signal signal to noise ratio correspondences in advance according to emulated data, when described difference greater than zero the time, make described CQI _NewEqual described CQI _OldAdd the offset of current feedback signal signal to noise ratio correspondence; When described difference less than zero the time, make described CQI _NewEqual described CQI _OldDeduct the offset of current feedback signal signal to noise ratio correspondence;

This method has been utilized the gradually changeable of channel quality more fully, according to ACQI-CQI _OldDifference judge the possible change direction of channel, and then according to change direction and with reference to current feedback signal signal to noise ratio with CQI _OldCompensate a rational offset and obtain the ACQI that next TTI uses _New

Method five,

Similar with method four, the feedback loop reference signal signal to noise ratio makes ACQI _New=CQI _Old+ β * f _(SNR), the definition of β is with method three, f _(SNR)Be feedback signal signal to noise ratio and CQI according to CQI _OldApproximate definite CQI _NewValue, f _(SNR)Be an approximate penalty function, when described difference greater than zero the time, make described CQI _NewEqual described CQI _OldAdd the functional value of current feedback signal signal to noise ratio correspondence; When described difference less than zero the time, make described CQI _NewEqual described CQI _OldDeduct the functional value of current feedback signal signal to noise ratio correspondence.

Method five and method four are similar, obtain functional relation between channel quality SNR and the offset according to emulated data, compensate then.

Embodiment two

As shown in Figure 4, receiving terminal periodically feeds back to transmitting terminal with the modulation of receptivity correspondence and the absolute magnitude ACQI of coded system index CQI, and whether when transmitting terminal receives described ACQI at every turn, it is reliable to utilize following step to detect ACQI:

The ACQI that S201, calculating receive deducts modulation and the coded system index CQI of an adjacent last Transmission Time Interval TTI _OldThe absolute value of difference;

S202, judge described absolute value whether smaller or equal to first threshold value of setting, if then judge the reliable and execution in step S204 of the ACQI that receives; Otherwise continue;

S203, judge whether current feedback signal signal to noise ratio exceeds second threshold value of setting, if then judge the reliable and execution in step S204 of the ACQI that receives; Otherwise judge that this ACQI that receives makes mistakes and execution in step S205;

Here, first threshold value and second threshold value utilize empirical data to determine according to the gradually changeable of channel.

In the present embodiment, for further strengthening the judgement of ACQI reliability, on the basis of embodiment one, transmitting terminal judges whether current feedback signal signal to noise ratio exceeds second threshold value of setting again, if exceed then illustrate that sudden change has taken place channel really, can think that the ACQI of higher (or on the low side) is reliable, otherwise judge that this ACQI that receives makes mistakes.

S204 is identical with embodiment one, if transmitting terminal is judged when the ACQI that receives is reliable, directly with the CQI of this ACQI as adjacent next TTI _New

Make mistakes if the S205 transmitting terminal is judged the ACQI that receives, redefine the CQI of adjacent next TTI according to one of method described in the embodiment one _New

As shown in Figure 5, the feedback control system of realization embodiment one and embodiment two comprises: first feedback control module and second feedback control module that is positioned at the data transmission end that are positioned at data receiver; Wherein:

Described first feedback control module periodically will feed back to described second feedback control module with the absolute magnitude ACQI of corresponding modulation of receptivity and coded system index CQI;

Comprise detecting unit in described second feedback control module, this detecting unit calculates modulation and coded system index CQI that the ACQI that receives deducts an adjacent last Transmission Time Interval TTI at every turn when receiving described ACQI _OldThe absolute value of difference; Whether judge described absolute value smaller or equal to first threshold value of setting,, otherwise judge that this ACQI that receives makes mistakes if judge that then the ACQI that receives is reliable; Perhaps

This detecting unit calculates modulation and coded system index CQI that the ACQI that receives deducts an adjacent last Transmission Time Interval TTI at every turn when receiving described ACQI _OldThe absolute value of difference; Whether judge earlier described absolute value smaller or equal to first threshold value of setting, if judge directly that then the ACQI that receives is reliable; Otherwise whether the signal to noise ratio snr of judging current feedback signal again exceeds second threshold value of setting, if judge that then the ACQI that receives is reliable, otherwise judges that this ACQI that receives makes mistakes.

Also comprise determining unit in described second feedback control module, connect described detecting unit; Redefine available CQI according to one of five kinds of methods described in the embodiment one _New

Embodiment three

The embodiment of second kind of feedback provided by the invention as shown in Figure 6, present embodiment carries out the detection of reliability by feedback information being added CRC (Cyclic Redundancy Check Code cyclic redundancy) check code, specifically comprises the steps:

S301, receiving terminal periodically feed back modulation and the absolute magnitude ACQI of coded system index CQI and the CRC check sign indicating number of this ACQI of receptivity correspondence to transmitting terminal;

When S302, transmitting terminal receive described ACQI at every turn, behind the described ACQI of the correct verification of CRC check sign indicating number according to correspondence, judge the reliable and execution in step S303 of the ACQI that receives; Otherwise judge that this ACQI that receives makes mistakes and execution in step S304;

S303, when transmitting terminal judges that the ACQI receive is reliable, with the CQI of this ACQI as adjacent next TTI _New

S304, when transmitting terminal judges that the ACQI receive makes mistakes, redefine described CQI according to the method one described in the embodiment one, method three, method four or method five _New

Still consult shown in Figure 5ly, realize that the present embodiment feedback control system comprises: be positioned at first feedback control module of data receiver and be positioned at second feedback control module of data transmission end; Wherein:

Described first feedback control module is periodically to described second feedback control module feedback and the absolute magnitude ACQI of corresponding modulation of receptivity and coded system index CQI and corresponding CRC check sign indicating number;

Also comprise determining unit in described second feedback control module, connect described detecting unit; Determine described CQI according to the method one described in the embodiment one, method three, method four or method five _New

Obviously, those skilled in the art can carry out various changes and modification to the present invention and not break away from the spirit and scope of the present invention.Like this, if of the present invention these are revised and modification belongs within the scope of claim of the present invention and equivalent technologies thereof, then the present invention also is intended to comprise these changes and modification interior.

Claims

1, a kind of feedback, receiving terminal periodically will feed back to transmitting terminal with the absolute magnitude ACQI of corresponding modulation of receptivity and coded system index CQI, when transmitting terminal receives described ACQI at every turn, carry out following step:

2, the method for claim 1, it is characterized in that, also comprise in the described steps A 2, transmitting terminal is at described absolute value during greater than described first threshold value, judge once more whether current feedback signal signal to noise ratio exceeds second threshold value of setting, if judge that again the ACQI that receives is reliable, otherwise judge that this ACQI that receives makes mistakes.

3, method as claimed in claim 1 or 2 is characterized in that, also comprises in the described steps A 2:

Make described CQI _NewEqual described CQI _Old

4, as claim 2 or 3 described methods, it is characterized in that described feedback signal is meant the feedback signal of carrying described ACQI or other feedback informations.

5, a kind of feedback is characterized in that, comprises the steps:

6, method as claimed in claim 5 is characterized in that,

Make described CQI _NewEqual described CQI _Old

7, a kind of feedback control system, comprise first feedback control module that is positioned at data receiver and second feedback control module that is positioned at the data transmission end, described first feedback control module periodically will feed back to described second feedback control module with the absolute magnitude ACQI of corresponding modulation of receptivity and coded system index CQI, it is characterized in that, comprise detecting unit in described second feedback control module;

8, as right 7 described systems, it is characterized in that, also comprise determining unit in described second feedback control module, connect described detecting unit;

When the ACQI that receives makes mistakes, determine described CQI according to one of following method _New:

Make described CQI _NewEqual described CQI _Old

9, a kind of feedback control system comprises first feedback control module that is positioned at data receiver and second feedback control module that is positioned at the data transmission end, it is characterized in that:

10, as right 9 described systems, it is characterized in that, also comprise determining unit in described second feedback control module, connect described detecting unit;

Make described CQI _NewEqual described CQI _Old