Estimation of rate of change of channel using fast start-up technique

Deals with a fast start-up estimation of rate of change of channel based on a training signal consisting of a self-orthogonal sequence repeated several times. A process of maximum likelihood estimation of the sampled impulse response of the channel is carried out on the receipt of each linearly distorted self-orthogonal sequence (excluding the first sequence which acts as a buffer). For the correct operation of the system, the channel impulse response must not change significantly over the duration of any one self-orthogonal sequence. Results of extensive computer simulation tests are presented. A theoretical model of the channel is studied which incorporates the worst properties of both HF as well as mobile radio links, namely, frequency-selectivity and rapid fading rate