Method for obtaining channel quality in multi-input multi-output system
A technology of channel quality and acquisition method, which is applied in the field of calculation of channel quality indicators in multiple-input multiple-output systems, and can solve problems such as being unable to make a prediction
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
no. 1 example
[0159] In LTE Release 8, the transmission based on the single-antenna port 5 belongs to an application of a single-stream beamforming (Beamforming, BF) technology. In order to enhance the performance of the downlink non-codebook transmission method, a new transmission method is proposed in the enhanced version of LTE Release 9, which belongs to a non-codebook spatial multiplexing method with a rank of 2, that is, dual-stream BF technology for the transmission of two antenna ports.
[0160] In the single-user dual-stream BF scenario, the eNB can decide the precoding processing method by itself because it is not based on the codebook. Although the eNB generally makes the precoding vectors of the two layers orthogonal, due to various errors in the actual system, when the signal reaches the UE, the interference between the layers is difficult to avoid. In this case, the interference average can be used Method to calculate the CQI:
[0161] The CQI of the first layer is:
[0162...
no. 2 example
[0206] Dual-stream BF can also support multi-user MIMO, and each user occupies only one stream (rank is 1). The first embodiment requires the rank of the single-user channel to be 2, and if the rank of the channel is 1, multi-user MIMO is required for spatial multiplexing. If the rank of the channel is 1 and there is no user pairing, it is necessary to use single-user single-stream BF. In this single-stream BF mode, to support dynamic switching between single-user single-stream BF and multi-user BF, this embodiment adopts a differential CQI feedback method.
[0207] First calculate the CQI of the single-stream BF:
[0208] CQI SU , 1 = Q ( SINR SU , 1 ) = Q ( f 1 ...
no. 3 example
[0249] Mode 5 of Release 8 of LTE supports codebook-based multi-user MIMO transmission. In Release 10 of Enhanced Long Term Evolution (LTE-Advanced), UE can also use codebook when feeding back CQI and PMI, but in order to enhance the performance of MU-MIMO, eNB can still support non-codebook multi-user during transmission MIMO transmission. In this mode, since DMRS is also used for demodulation, the implementation of multi-user dual-stream BF can also use DMRS to estimate interference. The difference from multi-user dual-stream BF is that more than two users can be multiplexed. The following is the CQI calculation method of user m' when there are M users:
[0250] SINR MU , m ′ = f m ′ * ( R ^ ...
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More 