The problem of joint symbol and frame synchronization in direct-detection optical PPM communication systems under the assumption of known slot timing is considered here. The optimum maximum-likelihood (ML) and sub-optimum rules for this joint symbol and frame synchronization problem are derived. The reason of Georghiades's (1985) incorrect ML rule is discussed in this paper.

GMSKIndex=0.5 -----) Signal Gaussian filter g(t,B) -----t ABSTRACT This paper considers the detection performance of a serial thresholding receiver for precoded binary GMSK signal with BT=O.5. The conditional symbol (bit) error probability of the GMSK signal with carrier phase and timing errors is derived and compared to that of unJiltered BPSK. It is shown that the GMSK signal has practically the same performance as the ideal BPSK signal in the absence of sync errors and that the GMSK signal is more sensitive to carrier phase error but much more robust to symbol timing error than is the BPSK signal.

No abstract

No abstract

Absfracr-In this paper we consider the problem of detecting an uplink time probe of a frequency hopping communication system with uplink partial processing employing symmetric differential phase shift keying (SDPSK) signaling. Analytical and simulation results on the probability of detection error for a probe signal received over multiple bop durations in noise and jamming, using both bard and soft decision bop combining, are presented.