Title | Multi-Tone Transmissions over Two-User Cognitive Radio Channel with Weak Interference |
Authors | Na Yi, Yi Ma, Rahim Tafazolli |
Journal/Conference name | PIMRC 2008 |
Date of Publication | 15 Sept 2008 |
Work Area | Delivery Efficiency |
Abstract | A transmitter with cognitive capability can sense talk between the other transmitter-receiver pairs. When this transmitter knows full or partial message of the others, it can choose an efficient strategy to access the transmission medium. This is referred to as cognitive radio channel. This work aims to investigate multi-tone transmission over two-user cognitive radio channels where cross-talk interference is weak. Cognitive transmitter (Tx$1$) is assumed to have full knowledge of message that is sent by the other transmitter (Tx$2$) to its corresponding receiver (Rx$2$). Channel capacity is carefully analyzed for frequency-selective scenarios. Efficient power-allocation strategies at Tx$1$ are investigated for various wireless environments. It is shown that Tx$1$ can find an efficient resource-accessing strategy if the channel gain of Tx$1$-Rx$1$ (the corresponding receiver) link is larger than the channel gain of Tx$2$-Rx$2$ link. In this case, the cognitive transmitter Tx$1$ can offer better performance by employing equal power allocation approach. Otherwise, it is not worthy for Tx$1$ to access transmission medium of Tx$2$-Rx$2$ link. |