基于三级调制的多带OFDM-UWB多址算法

根据多带OFDM-UWB通信系统的特点，提出一种基于三级调制的多带OFDM-UWB多址算法—TSM-MA算法。该算法通过MC-CDMA、OFDMA与FHMA技术的融合，实现多种技术的优势互补，减少了多用户间的干扰，充分利用了各子载波的可用资源。为了降低接收机的复杂度，TSM-MA算法采用了二级扩频与二级跳频的机制。结果表明，TSM-MA算法的多址性能要明显优于时频多址算法的性能，可以改善系统信噪比3dB左右，并且在接收机的复杂度方面也有一定的优势。

Multiple access based on three-stage modulation in multi-band OFDM-UWB system

According to the characteristics of multi-band orthogonal frequency-division multiplexing ultra-wideband(OFDM-UWB) system,a multiple access based on three-stage modulation(TSM-MA) was proposed.It combined multi-carrier code division multiple access(MC-CDMA) with orthogonal frequency division multiple access(OFDMA) and frequency hopping multiple access(FHMA),carried out the advantages of the three multiple access techniques.It reduced the multiple access interference and made full use of the available resource of the channel.The two-stage spread spectrum and two-stage frequency hopping were used to the TSM-MA for reducing the complexity of receiver.Simula-tion results showed that TSM-MA has obvious advantages in bit error rate(BER) performance over time frequency code multiple access(TF-MA) about 3 dB and lower complexity than that of TF-MA.