Channel parameter reporting method and apparatus, communication terminal, and base station

Abstract

The invention provides a channel parameter reporting method and an apparatus, a communication terminal, and a base station. The channel parameter reporting method is used for a communication terminal in an LTE system and includes: a reporting mode configuration message sent by the base station is received, and the reporting mode configuration message indicates that the communication terminal does not report a pre-coding matrix index PMI; channel parameters are determined by employing a pre-cording mode according to reference signals sent by the base station, and the channel parameters comprise the optimal rank index RI, the PMI, and a channel quality indicator CQI corresponding to the RI and the PMI; and the CQI is reported to the base station so that the base station determines the modulation and coding scheme MCS, the pre-cording matrix, and the rank number employed during data transmission according to the CQI. According to the technical scheme, UE calculates the CQI according to a pre-coding mode, and the UE does not need to report the PMI so that the influence on the system performance due to the difference of the calculating method of the CQI at the UE terminal and the data transmission method of eNB is avoided, the cost of signaling is reduced, and the system throughput is increased.

Description

technical field [0001] The present invention relates to the communication field, in particular to a method and device for reporting channel parameters, a communication terminal and a base station. Background technique [0002] In the current LTE system, there are 10 multi-antenna transmission modes (transmission mode, TM) in the downlink. Among them, TM7, TM8, TM9, and TM10 can perform beamforming transmission based on the channel reciprocity of the TDD system. In addition, TM8, TM9, and TM10 Precoding-based data transmission is also possible. figure 1 It is a schematic flow chart of the reporting method of channel parameters in the beamforming transmission scheme based on the channel mutuality of the TDD system. As shown in the figure, the reporting method includes: [0003] Step S100, the base station eNB configures that the UE does not need to report PMI and RI; [0004] Step S102, the UE selects the optimal RI and PMI in a transmission diversity manner according to the...

AI Technical Summary

Problems solved by technology

[0012] In the existing beamforming transmission scheme based on channel heterogeneity of the TDD system, the communication terminal UE calculates CQI (ChannelQualityIndicator, channel quality indicator) according to transmitdiversity (transmission diversity), and the base station eNB will use precoding in actual transmission Technology, through the uplink SRS (Sounding Reference Signal, channel sounding reference signal) to estimate the downlink channel to calculate the precoding matrix to improve the receiving performance, which makes the UE's CQI calculation method different from the eNB's actual data transmission method. This difference usually leads to the eNB in ​​the actual The MCS (Modulation and Coding Scheme, modulation and coding strategy) used when transmitting data is low, thereby reducing the system throughput, especially in the case of using large-scale antennas, it is necessary to virtualize multiple physical antenna ports to send CRS (Common Reference Signal, Common reference signal) or CSI-RS (ChannelStateIndicationReferenceSignal, channel state indication reference signal), virtualization will reduce the transmit power of the antenna port, which will further reduce the accuracy of CQI calculation

[0013] In the precoding-based data transmission scheme, the UE needs to report PMI (PrecodingMatrixIndicator, the number of rows and columns of the precoding matrix) periodically or aperiodically, and there is a certain signaling overhead

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