衰落信道下基于接收机信标感知的频谱共享

Spectrum Sharing Through Receiver Beacons in Fading Channels

理想的主、次系统频谱共享应尽量使次级用户发射机与主用户接收机处于互为对方的保护边界和干扰边界的临界状态。本文基于此临界状态对信标感知灵敏度和次级用户发射功率的要求,通过分析信道衰落和双向信道非对称性引起的临界干扰概率,首次针对基于接收机信标感知的频谱共享方法,给出了衰落信道下满足主用户干扰约束的次级用户发射功率约束机制。针对单个工作频段存在多个主用户接收机的(广播)场景,以距次级用户发射机最近的主用户接收机为干扰保护目标,通过分析信标的多个衰落副本的累积作用对信标感知的影响,进一步给出了这种场景下的次级用户发射功率约束与主用户临界干扰概率的关系。

Ideal spectrum sharing should try to make the pair of co-channel secondary transmitter（ST） and primary receiver （PR） into a critical state that the ST is the PR＇ s protection boundary while the PR is the ST＇ s interference boundary.Based on the conditions of beacon sensing and secondary transmitting power in that state,we analyze the critical interference probability（CIP） caused by the fading and nonreciprocity of the bidirectional channels,and give out the secondary transmit-power constraint（STPC） mechanism for given interference constraints the first time for spectrum sharing through receiver beacons in fading channels,from which it is noted that,for high spectrum utilization the frequency of beacon channel should be chosen carefully so that its propagation characteristics can be highly correlated with its indicating primary band.The study is further extended to the scenario with multiple PRs tuned on the same primary band simultaneously as in broadcast services,where through statistical modeling of aggregate received beacon power, the CIP and STPC are given out with the nearest PR to the ST as the interference protection target.