Abstract:This paper investigates a serial concatenation of Low-Density Parity-Check (LDPC) codes with Minimum Shift Keying (MSK) when the receiver employs iterative decoding and demodulation. First, the RCPE and NRCPE modes of the MSK modulator are described, then the error correlation in the Recursive CPE (RCPE) MSK demodulator and the overall loop in the joint Tanner graph are analyzed. Finally a new design rule is developed which allows the serially concatenated system not to employ interleavers. Simulation results show that the proposed design rule reduces the impact of the error correlation in a simple and effective way.