Selective limited feedback method for cooperative multicast transmission system

Abstract

The invention discloses a selective limited feedback method for a cooperative multicast transmission system. Therefore, a problem of high costs on average feedback in the prior art can be solved by utilizing the method provided in the invention. The method comprises the following steps that: (1) a sub-codebook is generated by utilizing random vector quantization and is also stored to a to-be-served user terminal and a cooperative base station end; (2), a to-be-served user obtains a downlink channel vector through channel estimation; (3), the to-be-served user carries out codebook selection on the downlink channel vector so as to obtain corresponded a code word sequence number; (4) the to-be-served user calculates a signal to noise ratio of a single-link channel gain; (5), the to-be-served user make comparison between the signal to noise ratio and a preset signal to noise ratio threshold value; if the signal to noise ratio is less than the preset signal to noise ratio threshold value, the to-be-served user does not feedback the corresponded code word sequence number; if the signal to noise ratio is not less than the preset signal to noise ratio threshold value, the to-be-served user feedbacks the corresponded code word sequence number; and the signal to noise ratio threshold value is set according to an average feedback cost required by the system. According to the invention, codebook connection is utilized as the basis; and limited feedback and selective feedback are combined, so that average feedback costs can be substantially reduced.

Description

technical field [0001] The invention belongs to the technical fields of mobile communication and wireless communication, and in particular relates to a selectivity limited feedback method for a cooperative multipoint transmission system. Background technique [0002] In order to meet the new requirements of the enhanced long-term evolution LTE-A system in terms of frequency, bandwidth, peak rate, average throughput, edge throughput, delay and compatibility, the third generation partnership project 3GPP is working on the enhanced long-term evolution LTE-A Many new key technologies have been proposed in the A system, and the coordinated multi-point transmission technology is one of them. [0003] The Enhanced Long Term Evolution LTE-A system uses Orthogonal Frequency Division Multiple Access (OFDMA) as its downlink multiple access technology, which uses orthogonal subcarriers to distinguish different users, so that there is almost no user interference in the cell. However, in...

AI Technical Summary

Problems solved by technology

In this way, by increasing the preset SNR threshold γ th , can reduce the average feedback overhead of the system to a certain extent, but this is at the expense of system performance

This method does not do any processing on the downlink channel vector, but directly feeds back. In the case of ensuring better performance, the average feedback overhead is still relatively large

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