Block coded noncoherent MSK

Noncoherent demodulation and coding of minimum-shift keying (MSK) is considered. using the framework of noncoherent maximum likelihood block estimation (N-MLBE), it is shown that the performance of MSK with N-MLBE tends to that of binary noncoherently orthogonal FSK (frequency-shift keying). Furthermore, a demodulation strategy, N -2 out of N noncoherent estimation ([N-2/N ]-NE), is introduced and shown to improve the performance of noncoherent MSK beyond that of noncoherently orthogonal FSK. The key feature that makes all the structures give an improved performance is the phase continuity of MSK and the coding properties that this inherent memory induces. Further performance improvement by using binary and nonbinary block codes with hard-decision decoding is considered for MSK with the noncoherent demodulation methods. It is shown that nonbinary block codes are very suitable for MSK systems with [N-2/N ]-NE demodulation