基于ISCP-DPSK调制的直接序列扩频技术  

Direct Sequence Spread Spectrum Using ISCP-DPSK Modulation

作　　者：张剑[1] 周兴建[1] 卢建川[1] 

机构地区：[1]中国西南电子技术研究所,成都610036

出　　处：《电讯技术》2013年第5期579-582,共4页Telecommunication Engineering

基　　金：国家重点实验室基金(9140C020101100C090C02)~~

摘　　要：使用符号内连续相位差分相移键控(ISCP-DPSK)调制的直接序列扩频方法可以在实现扩频抗干扰的同时保留ISCP-DPSK调制信号的准恒包络特性和优良的频谱特性,有利于非线性和功率受限的应用场合。由于采用非相干的信号解扩解调方法,避免了低信噪比下的载波和相位估计与跟踪,简化了系统设计。计算机仿真表明,基于ISCP-DPSK调制的直接序列扩频能有效对抗本振偏离、多普勒频移等引起的符号间相位变化影响,8倍扩频和16倍扩频的增益仅与理论值分别相差0.1 dB和0.2 dB。A method combining direct sequence spread spectrum （DSSS） with inner symbol continue phase dif- ferential phase shift keying （ISCP-DPSK） is proposed to maintain the ISCP-DPSK＇s properties of both quasi con- stant envelope and high spectrum efficiency, which makes it suit for application in nonlinear and power limited environment. Furthermore, the noncoherent detection of DSSS system avoids the estimation and track of carrier and phase at low signal-to-noise ratio（SNR）, which simplifies the system design. The simulation demonstrates that the proposed method is immune to the phase shift caused by Doppler, carrier frequency offset and so on, the gains of the eight times sequence spread and the sixteen times sequence spread degrade only 0.1 dB and 0.2 dB resoectively in comparison with those of under ideal condition.

关 键 词：直接序列扩频 ISCP-DPSK 准恒包络 扩频增益 

分 类 号：TN914.4[电子电信—通信与信息系统]