An adaptive algorithm for estimating wireless communication channel

An adaptive algorithm for real-time channel estimation is proposed, which is a blind estimation of signal-to-interference ratio and signal-to-noise ratio. It works well in the case of multiple interferences and noise by using an improved adaptive k-NN technique. The channel in wireless security communications, such as adaptive frequency hopping (AFH), would be taken as an example to show the validity of the proposed algorithm. The algorithm is particularly effective in the case of noise-free signal disturbed by interferences of the known type. In our discussion, the signal is π/4 DQPSK, and the interferences and noise are GFSK, CW, and AWGN. The reason why we assume the interferences and noise are GFSK, CW and AWGN is discussed in the full paper. When the signal or interferences are of the other types, the estimator given in the full paper also brings good results. The algorithm has been implemented on the platform based on ADSP21160, and it works well.