Comparison of Demodulation Techniques for MSK

For MSK, three demodulators are compared. The first demodu­lation algorithm, partially coherent demodulation, is based on a classical matched filter approach combined with feedforward phase synchronization, whereas the second algorithm, block demodulation, is based on minimizing a distance measure based on the symbol vector trial and the observed differential phase vector. The third algorithm is based on the same distance measure, however the minimization is carried out using the viterbi algorithm. We provide a derivation of the second algorithm. It is shown that the first approach is superior both in performance and computational complexity. The first algorithm also exhibits the best robustness properties in the case of signal impairments.