Recent work on proper design of signals in single carrier 4φ-PSK systems is summarized. The main conclusion is that it is possible to minimize the overall degradation due to nonlinearities and adjacent channel interference by careful choice of pulse shaping filters. We also show that the penalty, in terms of power, for not being careful can be high. An example is given showing effects of co-channel interference degradation as well as timing jitter degradation.

Joint optimization of transmitter and receiver filters in a pulse-amplitude modulation (PALM) system with an arbitrary but fixed Viterbi detector is considered. Optimization is performed under an average transmitted power constraint with respect to a new criterion called the effective mean-square error (EMSE). It is shown that the optimization problem is convex. A necessary and sufficient condition for optimality is derived, and a method for optimization is proposed. Numerical results are obtained for a channel with coaxial cable characteristics.

The effects of filter shaping and nonlinearity in a coherent quadrature phase-shift-keyed (QPSK) system are investigated. Optimization of the receiver filter with respect to the meansquare error (MSE) is considered. Optimization is performed under two different constraints, corresponding to implementation of the filter at intermediate frequency and baseband, respectively. As an example a channel with a typical traveling-wave tube (TWT) nonlinearity is studied. Numerical results are obtained which describe the effect of different transmitter filter characteristics on system performance.

TheM-tuple weight distribution and high-order autocorrelations of binarym-sequences are related to the weight distribution of the shortened Hamming code, which is dual to them-sequence code. It is shown that good weight distribution and correlation properties can be achieved simultaneously only if them-sequence is sufficiently long.

Optimization of the transmitting filter in a PAM system using a Viterbi detector of constrained complexity is considered. The receiving filter is considered to be a whitened matched filter. A constraint on detector complexity is obtained by limiting the length of the system impulse response. The results are applied to a channel with coaxial cable characteristics. Comparison with other detectors shows that the Viterbi detector is preferable even when the length of the system impulse response is quite short.