OFDMA cognitive radio medium access control using multichannel ALOHA

We present an orthogonal frequency division multiple access (OFDMA) cognitive radio medium access control using multichannel ALOHA (OCR MAC). The performance of an infinite population based OCR system is numerically as well as theoretically analyzed in terms of throughput, delay, and data capacity. We evaluate the throughput versus delay tradeoff of OCR MAC with an agile OFDM channel selection. Especially, via simulation with a linear feedback model, we verify the proposed system and its tradeoff characteristics. The numerical results for the proposed CR MAC are compared with conventional non-agile CR MAC as well as pure ALOHA based CR MAC. We also investigate the data capacity for OCR with perfect or imperfect spectrum sensing whose capacity gap is reduced with a large number of channels.