凭借其巨大带宽处理增益,超宽带可在低于-41.3 dBm/MHz的超低功率谱下进行通信,这符合认知无线电中undelay频谱共享方式的要求,即认知用户的信号发射谱不会干扰其余合法用户.为此,各种频谱管理机构对UWB系统的发射功率有严格限制,因而设计满足频谱模板的UWB脉冲就变得至关重要.针对已有的满足频谱模板的UWB脉冲设计中存在的缺点,提出一种能获得更高频谱利用率的全新UWB脉冲,该脉冲具有良好的自相关特性,减少了时间受限情况下的多址干扰,极大提高了网络容量,与其他满足频谱模板要求的脉冲相比其性能是最好的,本文设计的UWB脉冲不受调制多址方式影响,在短距离无线通信和认知无线电中有广泛而重要的应用.
Resorting to the huge bandwidth proceeding gain, ultra wideband (UWB) can communicate under ultra low power spectrum, even lower than - 41.3 dBm/MHz, which satisfies the requirement of underlay spectrum share mode in cognitive radio, in this condition, the signal transmission spectrum of cognitive radio users will not disturb other primary users. Spectrum management organizations present strict limits to UWB transmission power, as a result, it is very important to design UWB pulse which can meet the need of spectrum mask. Aimed at the shortcomings of existing UWB pulses, a novel UWB pulse with good self correlation characteristic is presented, which can achieve higher spectrum efficiency, reduce the multiple access interference and improve the transmission quality of UWB system. Compared with other UWB pulses which are compliant with the mask, the pulse designed has better performance, and it is not affected by modulation scheme and suitable for any modulation format.