CN100536455C - Simplified characterization method for channel quality feedback information - Google Patents

Abstract

This invention relates to channel quality feedback information simplifying represent method in the communication technique field, which uses channel transmission characteristics of semi static property and The time zone multi-radium to represent whole zone signal channel quality information and through power percentage parameters to achieve controlled feedback accuracy and data volume to adapt system user number changer and materials occupancy change.

Description

Reduce the method for the feedback information volume of channel

Technical field

What the present invention relates to is a kind of method of communication technical field, is specifically related to a kind of method of feedback information volume of the reduction channel that is used for wideband OFDM system.

Background technology

Along with the continuous development of Radio Transmission Technology, the kind of wireless data service constantly increases, and comprises wireless Internet, the wireless video transmission, and VoIP etc., all are all, invariably the transmission rate of wireless data are had higher requirement.For satisfying above-mentioned requirements, in cdma2000 (1xEV-DV and 1x-EV-Do) and HighSpeed Downlink Packet Data Access (HSPDA) system, all used to have the high speed wireless data transmission technology that channel quality information detects (Channel Quality Information Measurement) and feedback.This technology at first detects wireless channel at controlled end transmission quality carries out the allocation of radio resources self-adaptive processing relevant with other with this feedback information to main control end subsequently.In the process of above-mentioned detection and feedback, a main problem is that feedback information will take a large amount of return link bandwidth, and in ofdm system, this problem is especially obvious.

Through the literature search of prior art is found, in the technical report of 3GPP tissue (3GPP TR 25.814V0.3.1 (2005-10), " Physical Layer Aspects for Evolved UTRA), adopted method based on block of sub-carriers (chunk).In these methods, the base station end need obtain the frequency domain transmission characteristic of channel quality, and these characteristics are to be that unit feeds back and obtains by the block of sub-carriers with the ofdm system frequency domain, it is many more that its deficiency is that the user participates in the block of sub-carriers of self-adaptive processing, and the feedback information volume that needs is also just many more.

Summary of the invention

The objective of the invention is at above shortcomings in the prior art, propose a kind of method that reduces the feedback information volume of channel.Make it can greatly reduce the expense of feedback information volume.

The present invention is achieved by the following technical solutions, when the present invention carries out channel-quality feedback between end of communicating by letter and end, utilizes the The quasi-static characteristics in the channel transfer characteristic, uses the channel quality information of the whole frequency domain of multipath tap characterizations of time domain; Simultaneously, reach by adjustment that Control and Feedback precision and feedback data amount change with adaptive system user number and the purpose of resource occupation variation to power percentage coefficient.

Below the present invention is further illustrated, may further comprise the steps:

1) carry out parameter setting in the main control end of communication system, promptly the initial value of power percentage coefficient η is 0.8;

2) obtain the time-domain representation form h (n) or the frequency domain representation form H (k) of channel transfer function at controlled end;

3) to time-domain representation form h (n), directly enter step 4); To frequency domain representation form H (k), carry out the IFFT conversion, obtain time domain channel shock response h (n);

4) utilize ${\hat{P}}_{\mathrm{est}}=\underset{l=0}{\overset{N-1}{\mathrm{\Σ}}}{\hat{g}}_{\hat{h}\left(n\right)}^2\left(l\right)$ Obtain the gross power of channel multi-path tap coefficient, wherein

The mould of N the tap coefficient of the corresponding h of difference (n), N is the integer more than or equal to 1,1 is more than or equal to 0 integer less than N;

5) right

Carry out descending ordering to form a tap coefficient sequence

${\hat{P}}_{\mathrm{MST}}=\underset{l=0}{\overset{J-1}{\mathrm{\Σ}}}{{\hat{g}}^{\′}}_{\hat{h}\left(n\right)}^2\left(l\right)$ For the tap coefficient power of selected J bar multipath and, wherein parameter J is more than or equal to 1 integer less than N;

6) ascendingly successively choose different parameter J, relatively ${\hat{P}}_{\mathrm{MST}}>\mathrm{\&eta;}\&CenterDot;{\hat{P}}_{\mathrm{est}}$ Whether set up, the minimum value of parameter J promptly satisfies when selecting this inequality is set up $J=\underset{0<J\&le;N}{\arg \min }\{{\hat{P}}_{\mathrm{MST}}>\mathrm{\&eta;}\&CenterDot;{\hat{P}}_{\mathrm{est}}\};$

7) according to the tap coefficient sequence

In before the information of J tap, obtain

The tap coefficient corresponding in the sequence with it, and then obtain complex tap coefficient corresponding among the h (n) and multidiameter position as feedback information, and utilize the upstream data feedback channel to transfer to the base station end;

8) main control end is determined the increase and decrease situation of η according to the carrying situation of user in the system, and upgrades this value.

Main control end is determined the increase and decrease situation of η value according to user's carrying situation of up link, and user's number increases the value of parameter η after a little while in system, thereby improves the value of parameter J, increases feedback information volume, improves the accuracy that channel is described.

Main control end is determined the increase and decrease situation of η value according to user's carrying situation of up link, and user's number reduces the value of parameter η for a long time in system, thereby reduces the value of parameter J, reduces feedback information volume, reduces the expense of system handles feedback information.

The communication system that the present invention was suitable for comprises various radio communications and mobile communication system, and main control end and communicating by letter of controlled end comprise between the user and user in the system, and between user and the base station, and any needs carry out the communication between the equipment of message transmission.

The present invention is when extracting the feedback information of channel quality, utilize the The quasi-static characteristics of channel transfer function, with the channel quality information of the whole frequency domain of multipath tap characterizations of time domain, channel quality information is directly proportional with the number of multipath tap rather than is directly proportional with the number of subcarrier in frequency domain piece.Compared with prior art, the present invention can greatly reduce the expense of feedback information volume in having the self-adaptive processing of feedback unit; Simultaneously, can reach the purpose that the Control and Feedback precision changes with variation of adaptive system user number and resource occupation by adjustment to power percentage coefficient.

Embodiment

The present invention utilizes the The quasi-static characteristics of channel transfer function, uses the channel quality information of the whole frequency domain of multipath tap characterizations of time domain.At first, classify by the channel transfer function result that certain reference signal obtains for controlled end, two kinds of situations are respectively: frequency domain channel impulse response H (k) and time domain channel shock response h (n).For the channel impulse response of frequency domain, it is carried out the IFFT conversion, obtain time domain channel shock response h (n); For the channel impulse response of time domain, directly enter follow-up operation.Determine the multipath number J that feeds back according to power percentage coefficient η, satisfy

$J=\underset{0<J\&le;N}{\arg \min }\{{\hat{P}}_{\mathrm{MST}}>\mathrm{\&eta;}\&CenterDot;{\hat{P}}_{\mathrm{est}}\}---\left(1\right)$

Wherein ${\hat{P}}_{\mathrm{est}}=\underset{l=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{\hat{g}}_{\hat{h}\left(n\right)}^2\left(l\right)$ Be the gross power of channel multi-path tap coefficient,

The mould of N the tap coefficient of the corresponding h of difference (n), ${\hat{P}}_{\mathrm{MST}}=\underset{l=0}{\overset{J-1}{\mathrm{\&Sigma;}}}{{\hat{g}}^{\&prime;}}_{\hat{h}\left(n\right)}^2\left(l\right)$ For the tap coefficient power of selected J bar multipath and,

Be right After carrying out descending ordering, a tap coefficient sequence of formation.

Feedback factor is directly proportional with the number of selected multipath among the present invention.Power percentage coefficient η can play the effect of regulating the feedback information precision, is responsible for the setting of this value by main control end.Adjust according to the number of user in the system subsequently.In system user's number after a little while, the η value can increase, and increasing on the basis of feedback information volume, makes the sign of channel quality more accurate; In system user's number for a long time, the η value can reduce to reduce the expense of feedback information volume.

For understanding technical scheme of the present invention better, below provide embodiment to be further described:

1) initial value that power percentage coefficient η is set at the base station of mobile communication system end is 0.8, and is sent to receiving terminal by certain downlink data broadcast channel;

2) travelling carriage in mobile communication system obtains channel transfer function time-domain representation form h (n) or the frequency domain representation form H (k) that other unit estimation obtains;

3) determine subsequent operation according to the form of channel transfer function: to time-domain representation form h (n), directly enter next step,, carry out the IFFT conversion and obtain its time-domain representation form for frequency domain representation form H (k);

4) utilize ${\hat{P}}_{\mathrm{est}}=\underset{l=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{\hat{g}}_{\hat{h}\left(n\right)}^2\left(l\right)$ Obtain the gross power of channel multi-path tap coefficient, wherein

The mould of N the tap coefficient of the corresponding h of difference (n), N is the integer more than or equal to 1, l is more than or equal to 0 integer less than N;

5) right

Carry out descending ordering to form a tap coefficient sequence

${\hat{P}}_{\mathrm{MST}}=\underset{l=0}{\overset{J-1}{\mathrm{\&Sigma;}}}{{\hat{g}}^{\&prime;}}_{\hat{h}\left(n\right)}^2\left(l\right)$ For the tap coefficient power of selected J bar multipath and, wherein parameter J is more than or equal to 1 integer less than N;

6) ascendingly successively choose different parameter J, relatively ${\hat{P}}_{\mathrm{MST}}>\mathrm{\&eta;}\&CenterDot;{\hat{P}}_{\mathrm{est}}$ Whether set up, the minimum value of parameter J promptly satisfies when selecting this inequality is set up $J=\underset{0<J\&le;N}{\arg \min }\{{\hat{P}}_{\mathrm{MST}}>\mathrm{\&eta;}\&CenterDot;{\hat{P}}_{\mathrm{est}}\};$

7) according to the tap coefficient sequence

In before the information of J tap, obtain

The tap coefficient corresponding in the sequence with it, and then obtain complex tap coefficient corresponding among the h (n) and multidiameter position as feedback information, and utilize the upstream data feedback channel to transfer to the base station end.

8) the base station end is determined the increase and decrease situation of η value according to user's carrying situation of up link, and upgrades each user's η value at the base station end.

According to above-mentioned implementation step, the present invention with adopt the traditional frequency domain channel feedback scheme compare, can Greatly reduce feedback information volume. Traditional frequency domain channel feedback scheme advances the channel impulse response of frequency domain Row is feedback one by one, when the subcarrier number is more in the wideband OFDM system, distributes for carry out resource at transmitting terminal, Need the accurate channel yield value that obtains on each subcarrier, namely need to transmit be directly proportional with sub-carrier number anti-Feedforward information. And the present invention only need to feed back the channel information that is directly proportional with the multipath number, can pass through power simultaneously The multipath number of the required feedback of percentage coefficient adjustment has played the effect that reduces feedback information volume.

Claims (3)

1, a kind of method that reduces the feedback information volume of channel is characterized in that, when carrying out channel-quality feedback between end of communicating by letter and end, utilizes the The quasi-static characteristics in the channel transfer characteristic, uses the channel quality information of the whole frequency domain of multipath tap characterizations of time domain; Simultaneously, reach by adjustment that Control and Feedback precision and feedback data amount change with adaptive system user number and the purpose of resource occupation variation, specifically may further comprise the steps power percentage coefficient:

1) carry out power percentage coefficient settings in the main control end of communication system, promptly the initial value of power percentage coefficient η is 0.8;

2) obtain the time-domain representation form h (n) or the frequency domain representation form H (k) of channel transfer function at controlled end;

3) to time-domain representation form h (n), directly enter step 4); To frequency domain representation form H (k), carry out the IFFT conversion, obtain time domain channel shock response h (n);

4) utilize ${\hat{P}}_{\mathrm{est}}=\underset{l=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{\hat{g}}_{\hat{h}\left(n\right)}^2\left(l\right)$ Obtain the gross power of channel multi-path tap coefficient, wherein

The mould of N the tap coefficient of the corresponding h of difference (n), N is the integer more than or equal to 1,1 is more than or equal to 0 integer less than N;

5) right

Carry out descending ordering to form a tap coefficient sequence ${\hat{P}}_{\mathrm{MST}}=\underset{l=0}{\overset{J-1}{\mathrm{\&Sigma;}}}{\hat{g}}_{\hat{h}\left(n\right)}^{\&prime;2}\left(l\right)$ For the tap coefficient power of selected J bar multipath and, wherein parameter J is more than or equal to 1 integer less than N;

6) the ascending successively parameter J that chooses, relatively ${\hat{P}}_{\mathrm{MST}}>\mathrm{\&eta;}\&CenterDot;{\hat{P}}_{\mathrm{est}}$ Whether set up, the minimum value of parameter J promptly satisfies when selecting this inequality is set up $J=\underset{0<J<N}{\arg \min }\{{\hat{P}}_{\mathrm{MST}}>\mathrm{\&eta;}\&CenterDot;{\hat{P}}_{\mathrm{est}}\};$

7) according to the tap coefficient sequence

In before the information of J tap, obtain

The tap coefficient corresponding in the sequence with it, and then obtain complex tap coefficient corresponding among the h (n) and multidiameter position as feedback information, and utilize the upstream data feedback channel to transfer to main control end;

8) main control end is determined the increase and decrease situation of η according to the carrying situation of user in the system, and upgrades the value of power percentage coefficient η.

2, the method for the feedback information volume of reduction channel according to claim 1, it is characterized in that, main control end is determined the increase and decrease situation of η value according to user's carrying situation of up link, user's number increases the value of parameter η after a little while in system, thereby improve the value of parameter J, increase feedback information volume, improve the accuracy that channel is described.

3, according to the method for the feedback information volume of claim 1 or 2 described reduction channels, it is characterized in that, main control end is determined the increase and decrease situation of η value according to user's carrying situation of up link, user's number reduces the value of parameter η for a long time in system, thereby reduce the value of parameter J, reduce feedback information volume, reduce the expense of system handles feedback information.