Convolutional interleaving for digital radio communications

Interleaving enhances the quality of digital transmission over the radio fading channel. This enhancement comes at the cost of introducing additional time-delay, memory space requirements, and system complexity. This paper describes commonly used interleaving techniques. It addresses the realization and performance of a convolutional interleaver that cuts down time-delay and memory space increase considerably. Base-band computer simulations are presented for convolutionally coded and interleaved QPSK transmission over Rayleigh and Rician flat-fading channels at different interference levels.