A multiple-input multiple-output (Multiple-Input Multiple-Output, MIMO) system greatly improves a data transmission rate of a wireless communication system through configuring multiple antennas at a transmitting end and a receiving end of a base station respectively, and has been adopted by a series of wireless standards, such as a long term evolution (Long Term Evolution, LTE), a long term evolution-advanced (Long Term Evolution-Advanced, LTE-A) and the like. The performance of the above-mentioned wireless communication system is further improved by adopting some advanced MIMO technologies.
Taking a multi-user MIMO (Multi-User MIMO, MU-MIMO) technology as an example, the base station provides services for multiple UEs by using different beams formed on an antenna array. In the above-mentioned process, the base station needs to acquire a CSI of a downlink channel between the base station and each UE, so as to adjust the beams and schedule transmitting. The above-mentioned CSI is fed back by the UE served by the base station through an uplink channel of the base station. The more precise the fed-back CSI is, and the higher the promotion of the performance of the downlink channel is, which means that more uplink overhead is needed to feed back the CSI with high precision, so the fed-back CSI needs to be compressed and coded to reduce the uplink overhead.
The CSI is transformed from a frequency domain to a time domain for compressing and coding in the prior art. However, related parameters of a coding mode of the CSI are preset. Once the parameters are set, in a relatively long communication process, even if the fed-back CSI is distorted seriously after reestablishment to cause decline of the downlink performance of the base station, the precision of the fed-back CSI is not modified anymore, so that the feedback overhead brought by the CSI is not modified any more in this communication process. Under the above-mentioned condition, when the uplink channel state of the base station is relatively good and more data may be transmitted, the precision of the CSI cannot be improved through improving the feedback overhead to improve the downlink performance of the base station; when the uplink channel state of the base station is relatively poor, maintenance of the original feedback overhead may exceed the uplink channel load of the base station, so that a large amount of error codes appear in the feedback process, and the base station can not accurately reestablish the compressed CSI, thus correspondingly causing decline of the downlink performance of the base station.
USPTO Backgrounds
USPTO Backgrounds