Joint hop-timing estimation for FH signals using a coarsely channelized receiver

This paper addresses the joint hop-timing (epoch) estimation problem for a desired frequency-hopping (FH) signal plus an interfering FH signal using a coarsely channelized pre-processor which suppresses the frequency and phase dependence of the signals. The signals are modeled with the same hop rate and candidate hop frequencies, but with distinct power and timing epochs. Coarse channelization implies a bank of filters, much smaller in number than the size of the candidate hop frequency set, which covers the total shared bandwidth. It is shown that the Viterbi algorithm can be used to efficiently implement the maximization over the frequency sequences. Performance evaluation is presented via extensive computer simulations, showing that the estimates are unbiased and consistent whenever the signal powers are distinct. When the co-channel signal-to-interference ratio increases towards one this estimator deteriorates in performance