In multiuser multiple-inputmultiple-output (MU-MIMO) systems, limited feedback schemes using a vector quantization codebook (VQC) for partial channel state information (CSI) can enable a base station (BS) to enhance the sum throughput at low feedback rates. However, the VQC has a limited throughput gain, although it requires a great deal of memory and complexity as the feedback rate increases. Therefore, we propose a high-precision feedback technique by using sparse approximation and compression called compressive feedback (CF). By using the sparse approximation with a unitary codebook and the compression via a good compression matrix, CF achieves greater sum throughput than VQC. Our analysis of the maximum achievable sum rate verifies the superiority of CF over VQC.
All Science Journal Classification (ASJC) codes
- Automotive Engineering
- Aerospace Engineering
- Electrical and Electronic Engineering
- Applied Mathematics