A general class of binary continuous-phase shift keying (CPSK) signals is defined, of which continuous-phase FSK (CPFSK) and continuous-phase chirp (CPC) signals are special cases. The structure and performance of suboptimal average matched filter (AMF) receivers with multibit observation are considered; both coherent and noncoherent detection of binary CPSK signals are investigated. Expressions suitable for numerical evaluation of such suboptimal CPSK receivers in the additive white Gaussian noise (AWGN) environment are given, and simplified expressions are derived for special cases. In particular, the coherent AMF receiver with optimised CPC and CPFSK signal parameters is shown to be equivalent to a generalised inphase and quadrature receiver. The relation between crosstalk and filter orthogonality is clarified for non-coherent AMF detection. Numerical examples for CPFSK and CPC signals are given.