A Kalman Filter-Based Channel Estimator for Generalized Group-Coherent Codes

In this paper we propose a semiblind algorithm for estimation of MIMO channel adapted for the use of groupcoherent codes. The performance of the proposed algorithm is evaluated for Rayleigh, flat, and time-varying MIMO channels. The proposed estimator considers a Kalman filter to track the channel in MIMO systems that employ group-coherent codes at the transmitter. Based on the estimated coefficients, the receiver evaluates the instantaneous SNR for each one of 2b f codes available in the transmitter, and then sends bf information bits to the transmitter for the choice of the more appropriate code to send the next block of data. Also, simulations are performed for transmissions under different mobility and quantized feedback channel conditions. Simulation results reveal that the proposed estimator provides a performance very close to the one that considers a perfect channel knowledge and also that the performance of the proposed kalman filter-based receiver is approximately the same for different quantized feedback conditions.