一种认知超宽带无线通信系统的设计与实现

Designment and implementation of cognitive ultra wideband wireless communication system

从改善UWB通信系统与常规无线电系统电磁兼容性角度出发,研究一种认知M元扩频UWB通信方案.与DS-UWB不同,依据所提方案,发送信号中M个近似正交的PN码随机出现,传输波形不存在循环周期性,信号频谱非常平滑,基本没有谐波状谱线,功率谱更类似于白噪声,隐蔽性更好,抗噪声性能更强,归一化误码特性随M的增大而改善,直至逼近香农限.为防止带内常规无线电信号恶化系统性能,在接收机前端设计了频谱感知与干扰避免算法,理论分析与仿真实验表明所提算法可有效对抗窄带干扰对系统带来的影响,大幅提高系统性能.该技术方案,在极低性噪比条件下的应急通信与隐蔽通信等领域有重要推广应用价值.

To improve the coexistence performance between ultra wideband （UWB） and incumbent wirelessradio, a novel M-ary spread spectrum UWB communication scheme based on cognitive radio （CR） isinvestigated. Unlike DS-UWB, M quasi-orthogonal pseudo noise （PN） sequences appear randomly inM-ary spread spectrum UWB signal, its spectrum is smoother than DS-UWB signal, and close to whitenoise. So M-ary UWB radio can obtain strong anti-jamming, anti-interception performance and the biterror rate （BER） is also improved with the increase of M. Meanwhile, the proposed spectrum sensing andinterference mitigation scheme can resist the strong narrowband interference effectively. The numericalresults have validated the expected performance and properties.