To improve spectrum utilization and minimize interference to Primary User (PU), an adaptive spectrum decision method is proposed for Secondary User (SU), while taking traffic load balancing and spectrum heterogeneity ...To improve spectrum utilization and minimize interference to Primary User (PU), an adaptive spectrum decision method is proposed for Secondary User (SU), while taking traffic load balancing and spectrum heterogeneity into consideration. Long-term statistics and current sensing results are integrated into the proposed decision method of spectrum access. Two decision methods, namely probability based and sensing based, are presented, compared and followed by performance analysis in terms of delay. For probability based spectrum decision, Short-Time-Job-First (STJF) priority queuing discipline is employed to minimize average residual time and theoretical conclusion is derived in a novel way. For sensing based decision we treat the interrupted service of SU as newly incoming and re-decision process is initialized to find available spectrum in a First-Available-First-Access (FAFA) fashion. Effect of sensing error in PHY layer is also analyzed in terms of extended average residual time. Simulation results show that, for relatively low arriving rate of SU traffic, the proposed spectrum decision method yields at least a delay reduction of 39.5% compared with non-adaptive method. The proposed spectrum decision can significantly improve delay performance even facing sensing errors, which cause performance degeneration to both PU and SU.展开更多
Interference between users is a significant issue for resource allocation in cognitive radio （CR） networks. The interference induced by the secondary users （SUs） to the primary users （PUs） derives from two aspe...Interference between users is a significant issue for resource allocation in cognitive radio （CR） networks. The interference induced by the secondary users （SUs） to the primary users （PUs） derives from two aspects： out-of-band leakage （OOBL）, spectrum sensing error （SSE）. Filter bank multicarrier （FBMC） has small out-of-band leakage and high spectral efficiency in comparison with that of the orthogonal frequency division multiplexing （OFDM）. In this paper, a resource allocation algorithm with considering SSEs in CR networks is proposed. The interference model is established first and then the proposed algorithm is divided into two steps, power is allocated to SUs under both interference constraints and total power budget. Simulation results based on FBMC and OFDM systems show that the proposed algorithm causes less interference to the PUs than that of the algorithm without considering OOBL, the performance of FBMC in interference and throughput is better than OFDM in CR networks.展开更多
基金supported partially by China's National 863 Program under Grant No.2009AA01Z207
文摘To improve spectrum utilization and minimize interference to Primary User (PU), an adaptive spectrum decision method is proposed for Secondary User (SU), while taking traffic load balancing and spectrum heterogeneity into consideration. Long-term statistics and current sensing results are integrated into the proposed decision method of spectrum access. Two decision methods, namely probability based and sensing based, are presented, compared and followed by performance analysis in terms of delay. For probability based spectrum decision, Short-Time-Job-First (STJF) priority queuing discipline is employed to minimize average residual time and theoretical conclusion is derived in a novel way. For sensing based decision we treat the interrupted service of SU as newly incoming and re-decision process is initialized to find available spectrum in a First-Available-First-Access (FAFA) fashion. Effect of sensing error in PHY layer is also analyzed in terms of extended average residual time. Simulation results show that, for relatively low arriving rate of SU traffic, the proposed spectrum decision method yields at least a delay reduction of 39.5% compared with non-adaptive method. The proposed spectrum decision can significantly improve delay performance even facing sensing errors, which cause performance degeneration to both PU and SU.
基金supported by the Science and Technology Research Project of Chongqing Municipal Education Commission (KJ1500435, KJ1500147)
文摘Interference between users is a significant issue for resource allocation in cognitive radio （CR） networks. The interference induced by the secondary users （SUs） to the primary users （PUs） derives from two aspects： out-of-band leakage （OOBL）, spectrum sensing error （SSE）. Filter bank multicarrier （FBMC） has small out-of-band leakage and high spectral efficiency in comparison with that of the orthogonal frequency division multiplexing （OFDM）. In this paper, a resource allocation algorithm with considering SSEs in CR networks is proposed. The interference model is established first and then the proposed algorithm is divided into two steps, power is allocated to SUs under both interference constraints and total power budget. Simulation results based on FBMC and OFDM systems show that the proposed algorithm causes less interference to the PUs than that of the algorithm without considering OOBL, the performance of FBMC in interference and throughput is better than OFDM in CR networks.
