Fundamental limits of diversity-embedded codes over fading channels

Abstract

Diversity-embedded codes for fading channels are high-rate codes that are designed so that they have a high-diversity code embedded within them. This allows a form of communication where the high-rate code opportunistically takes advantage of good channel realizations whereas the embedded high-diversity code ensures that at least part of the information is received reliably. This can also be thought as coding the data into two streams such that the high-priority stream has higher reliability than the low-priority stream. For SISO (single-input-single-output), SIMO, MISO and parallel fading channels, we characterize the achievable rates and reliability of the two streams in the high SNR regime in terms of the diversity-multiplexing tradeoff. We exhibit the performance gain over a single-stream code. We also show some constructions for finite block lengths that achieve the optimal performance