MSK Signals Research Articles

On the Effects of CW Interference on MSK Signal Reception

The probability of error in a minimum (frequency)-shift keying (MSK) system is obtained for the case of Gaussian noise only and for the case of CW interference in addition to Gaussian noise. Analysis is made for the fading channel case assuming Rayleigh fading. The results are compared with those of BPSK. It is found that MSK is more immune to CW interference than BPSK.

An Illustration of the MAP Estimation Method for Deriving Closed-Loop Phase Tracking Topologies: The MSK Signal Structure

This paper discusses the application of MAP estimation techniques to the problem of defining tracking loops for the estimation of various signal parameters. While this method has been applied to various signal structures such as BPSK and QPSK to show the reasonableness of certain loops such as the Costas loop, it is shown that the MAP method is useful for deriving tracking structures for signals for which no previously defined tracking loops exist. The method has already been applied to the case of deriving carrier tracking loops for unbalanced quadriphase (UQPSK). The particular application chosen to illustrate the MAP technique is the MSK signal. In particular, a closed loop is derived that jointly estimates both the carrier and clock phases.

The Use of Quasi-Bandlimited Pulses in MSK Transmission

A new class of basic pulses is introduced into the MSK signaling format to gain improvements in the out-of-band power spectral density characteristic. Some loss in communications efficiency is incurred, but the loss may in certain cases be outweighed by the spectral improvements that are made available.