Application of Per-Survivor Processing for Digital Mobile Radio

The bandwidth efficient modulation format OQPSK is implemented up to now merely in mobile radio systems which do employ spread spectrum techniques, i.e. it is not used in narrow band systems. This is due to the fact, that, in spite of its reduced performance degradation in non-linear channels in comparison to other linear modulation formats, for OQPSK no receivers were derived up to now, which satisfy the following requirements: fast tracking in time selective channels, short acquisition time in burst mode transmission, and resolution of intersymbol interference in frequency selective channels. In this paper a general approach for receiver implementations of differentially encoded OQPSK signals is given. Receiver structures for mobile radio applications are synthesised and investigated, which are all based on per-survivor processing (PSP).