Correlation Rotation Precoding For MIMO-OFDM Broadcast Channels

In multi-user MIMO downlink, multi-user interference(MUI) limits downlink performance. Linear precoding can effectively suppress MUI. On the other hand, according to the type of the interference, transmitter can exploit interference to enhance receiver performance without additional transmitter power. This thesis extend correlation rotation (CR) precoding to MIMO-OFDM broadcast channels. With power allocation in CR precoding, the downlink performance can be improved. In this thesis, the main contents are as follows:1. Deriving the instantaneous SINR expression of CR precoding. Through theoretical analysis and simulation, we discuss how CR precoding degrade average SER performance in some channels.2. Using the SINR expression, a power allocation method for CR precoding is proposed, which can improve average SER performance by balancing each receive signal power. Simulation results demonstrate the effectiveness of the proposed method.3. To improve throughput of MIMO-OFDM system employing CR precoding, a power and bit allocation method is proposed based on the derived SINR expression,. Simulation results show that the proposed method can effectively improve the downlink MIMO-OFDM system throughput.