摘要 |
The present invention relates to methods of transmitting a signal in a time division duplexing MIMO system and associated apparatuses. According to a first aspect of the present invention, there is provided a method of transmitting a signal in an eNodeB of a time division duplexing multiple input multiple output system. The method includes: A. receiving a signal from a user equipment in a space division multiplexing group and estimating uplink channel characteristics according to the received signal; B. determining reciprocity calibration information between the uplink channel characteristics and downlink channel characteristics; C. determining a downlink precoding matrix using zero forcing according to the uplink channel characteristics and the calibration information and transmitting a downlink signal to the user equipment in the space division multiplexing group according to the determined downlink precoding matrix. And the step B further comprises receiving information associated with a downlink vector channel matrix fed back from the user equipment in the space division multiplexing group and selectively updating the calibration information according to the information associated with the downlink vector channel matrix.
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