Blind adaptive modulation systems for wireless channels with binary feedback

In this paper, we investigate the performance of a blind adaptive modulation scheme that does not require any channel knowledge and just uses binary feedback, thereby decreasing feedback load. Retransmission of erroneous packet is not considered. In particular, we present an analytical framework for the performance evaluation of a simple wireless system in terms of receiver and transmitter structure. The system requires no knowledge of the channel and relies on a binary feedback. Slow and fast Rayleigh fading channel conditions are considered. The paper includes the derivation of closed-form expressions of the packet error rate (PER) and the spectral efficiency in the case of slow Rayleigh fading. In some cases, also closed-form expressions for the spectral efficiency are derived. Our results show relatively high PER but some applications such as voice communication can still operate in a satisfactory fashion in these conditions. Using coded modulation with high coding gain and increasing the number of blocks per time slot decrease the PER even more.