Performance of combined diversity reception and convolutionalcoding for QDPSK land mobile radio

摘要

Diversity reception and error correction coding are powerfulntechniques to combat multipath fading encountered in mobile radioncommunications. In order to improve the transmission performance of thenΠ/4-shift QDPSK signal in mobile radio channels, the authors proposena new scheme of combined coding and diversity reception, i.e.,ncombination of diversity reception employing code combining (CC) andnconvolutional coding employing error-and erasure correction Viterbindecoding. They also consider another combination scheme, i.e.,ncombination of diversity reception employing postdetection maximal rationcombining (MRC) and convolutional coding employing hard decision Viterbindecoding. They theoretically analyze the performance of the schemesntaking into account the additive white Gaussian noise (AWGN), random FMnnoise, co-channel interference (CCI), and intersymbol interference (ISI)ndue to multipath propagation delay spread. Numerical calculations arenpresented for the required average signal energy per bit-to-noise powernspectral density ratio (Eb/N0), required averagensignal-to-interference power ratio (SIR), tolerable maximum Dopplernfrequency, and tolerable rms delay spread needed to achieve a certainnaverage BER. The spectrum efficiency of the cellular system is alsoncalculated