Mutual information of multipath channels with imperfect channel information
IEEE Transactions on Communications
A review on spectrum sensing for cognitive radio: challenges and solutions
EURASIP Journal on Advances in Signal Processing - Special issue on advanced signal processing for cognitive radio networks
Multi-Dimensional Detector for UWB Ranging Systems in Dense Multipath Environments
IEEE Transactions on Wireless Communications
Sensing-Throughput Tradeoff for Cognitive Radio Networks
IEEE Transactions on Wireless Communications
Spatiotemporal Sensing in Cognitive Radio Networks
IEEE Journal on Selected Areas in Communications
Hi-index | 0.01 |
Spectrum sensing is critical for cognitive systems to locate spectrum holes. In the IEEE 802.22 proposal, short quiet periods are arranged inside frames to perform a coarse intra-frame sensing as a pre-alarm for fine inter-frame sensing. However, the limited sample size of the quiet periods may not guarantee a satisfying performance and an additional burden of quiet-period synchronization is required. To improve the sensing performance, we first propose a quiet-active sensing scheme in which inactive customer-provided equipments (CPEs) will sense the channels in both the quiet and active periods. To avoid quiet-period synchronization, we further propose to utilize (optimized) active sensing, in which the quiet periods are replaced by 'quiet samples' in other domains, such as quiet sub-carriers in OFDMA systems. By doing so, we not only save the need for synchronization, but also achieve selection diversity by choosing quiet sub-carriers based on channel conditions. The proposed active sensing scheme is also promising for spectrum sharing applications where both the cognitive and primary systems can be active simultaneously.