We study the impact of adopting a multi layer coding (MLC) strategy, i.e., the so-called broadcast approach (BA) on the throughput of Cognitive Radio (CR) spectrum sharing systems for general fading channels. First, we consider a scenario where the secondary transmitter, a part from the statistics, has no channel state information (CSI) of the cross link and its own link. We show that using BA improves the cognitive achievable rate compared to the outage rate provided by a single layer coding (SLC). In addition, we, also, observe numerically that 2-Layer coding achieves most of the gain. Then, we consider a situation where the secondary transmitter has a partial CSI about its own link through quantized CSI. Again, we compute the secondary achievable rate adopting the BA and highlight the improvement over SLC. Numerical results show that the advantage of MLC decreases as the rate of the feedback link increases. 1 © 2013 IEEE.
|Original language||English (US)|
|Title of host publication||2013 IEEE Global Communications Conference (GLOBECOM)|
|Publisher||Institute of Electrical and Electronics Engineers (IEEE)|
|Number of pages||6|
|State||Published - Dec 2013|