Part user feedback method for limited feedback of multiple-input multiple-output multi-user system

Abstract

A partial user feedback method for a limiting feedback multi-input and multi-output (MIMO) multi-user system arranges different random vector codebook sets for a base station and a user terminal. Wherein, a random vector codebook set at the base station is a subset of the random codebook set for the user terminal. Based on the resultant random vector codebook set for the user, the user measures a channel vector direction. After the channel vector direction of the user is quantified and positioned into the base station, the user of the random vector codebook set is eligible to feed back. In addition, the user eligible for feedback feeds back channel gain and channel direction vector index based on the random codebook set to the base station at each time slot. Thus, the base station carries out channel re-creating to the user in light of the channel direction vector index and the channel gain fed back by the user and the random vector codebook set at the base station. In addition, the base station only selects in a set of transmission users only participating in the feed back according to the re-created user channel. The present invention can reduce feedback expense, lower complexity for the base station to select a set of transmission user, enhance system throughput rate, apply to practical systems and decrease operation cost.

Description

technical field [0001] The invention relates to a multi-input multi-output multi-user system in wireless communication, in particular to a partial user feedback method based on limited feedback. Background technique [0002] The multi-user selective space division multiplexing method in the downlink MIMO system is an effective method to improve the throughput of the wireless communication system. [0003] "International Institute of Electronics and Electrical Engineers" (IEEE Journal on Selected Areas Communications (JSAC), Special Issue on 4G Wireless Systems, vol.24, issue 3, Mar.2006, pp.528-541.) proposed a A multi-user selection scheme for MIMO systems based on zero-forcing beamforming (ZFBF), which approaches the upper limit of throughput in MIMO multi-user systems with relatively low computational complexity. However, this method requires all users in the system to feed back the accurate value of their channels in each time slot, which will bring huge feedback overhe...

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Problems solved by technology

However, this method is only applicable when the total number of users is equal to the number of transmitting antennas. In the case of a large number of users, this method cannot take advantage of the system throughput brought by multi-user selection.

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