Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2501.06178 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Table of Contents:
- We consider the problem of Multiple-Input Multiple-Output (MIMO) communication with limited feedback, where the transmitter relies on a limited number of bits associated with the channel state information (CSI), available at the receiver (CSIR) but not at the transmitter (no CSIT), sent via the feedback link. We demonstrate how character-polynomial (CP) codes, a class of analog subspace codes (also, referred to as Grassmann codes) can be used for the corresponding quantization problem in the Grassmann space. The proposed CP codebook-based precoding design allows for a smooth trade-off between the number of feedback bits and the beamforming gain, by simply adjusting the rate of the underlying CP code. We present a theoretical upper bound on the \textit{mean squared quantization error} of the CP codebook for Multiple-Input Single-Output (MISO) communication system and utilize it to upper bound the resulting \textit{distortion} with perfect CSIT. We show that the distortion vanishes asymptotically. We compute the EGT baseline gain for MIMO systems with two receive antennas and observe that the CP gain approaches the EGT gain for MIMO system. The results are also confirmed via simulations for different types of fading models for both uncorrelated and correlated channels in the MISO and MIMO systems.