Hierarchical Diversity-Embedding Space-Time Block Coding

We propose a novel space-time transmission scheme with an unequal error protection (UEP) capability by providing different diversity levels and coding gains to the information bits according to their quality-of-service (QoS) requirements. This is achieved by transmitting the information symbols in layers each designed to operate at a different rate and diversity levels. Then, by selecting the information symbols from a hierarchical phase-shift-keying (PSK) constellation with carefully-designed separation angles, a variable coding gain is also realized. Applying this highly-flexible scheme to wireless multicasting, we demonstrate the performance gains in terms of information rates and coverage regions for both the basic and additional multicasting messages.