Design of differential quantization for low bitrate channel state information feedback in MIMO-OFDM systems

The feedback of channel state information have always posed a problem for the design of a communications system where the information is required at the transmitter. In most cases, changing the quantization levels or size of the codebook is used to control the amount of feedback bits. However, the number of quantization levels must be maintained at a sufficiently high level such that the feedback information can still be of use to the transmitter. This paper discusses the use of differential quantization methods to reduce the number of feedback bits required.