The optimum signal perturbation free transmit scheme to enhance the channel estimation of MIMO-OFDM system

There are many algorithms to improve the channel estimation of MIMO-OFDM system based on blind, semi blind and training methods. But still, it can be improved. Signal perturbation free transmit scheme is one of such schemes to improve it. This scheme transmits the data which bears the partial information of the correlation matrix of the transmitted signal to the receiver in order to cancel the signal perturbation error. In this paper, optimum signal perturbation free (SPF) transmit scheme which enhances channel estimation of frequency selective channel of MIMO-OFDM system is presented. The performance of SPF assisted semi blind channel estimation is enhanced in this work by the selection of a circularly shifted orthogonal pilot sequences on different antennas. The linear prediction based SPF transmit scheme with optimum pilot sequences known as optimum SPF transmit scheme outperform the performance of SPF scheme with orthogonal pilot sequences.