带宽受限下频谱分离对提高RDSS入站容量的影响分析

用户入站容量是RDSS系统设计的一个重要指标,主要受限于入站信号之间的多址干扰.提高扩频码速率可以增加人站容量,但卫星转发器带宽限制了扩频码速率的最大值,从而限制了单个扩频频谱入站信号容量最大值.在卫星转发器带宽受限情况下,提出了采用分离扩频频谱的方法来提高入站容量,并分别对扩频频谱分离为两个和三个的情况进行了详细分析,得出了两种分离扩频频谱方案下扩频码速率的最优值.仿真结果表明,在现有转发器带宽内分离为两个扩频频谱可以提高入站容量29％,分离为三个扩频频谱可以提高人站容量37％.

Analysis of spectral separation impact on RDSS System inbound capacity with bandwidth limit

Inbound user capacity is an important specification of RDSS system design,which is mainly limited by the inbound signal multiple access interference.To improve the spreading code rate can increase the corresponding inbound capacity.However,the satellite transponder bandwidth limits the maximum spreading code rate,which limits the maximum capacity of inbound signals with a single spread spectrum.As the satellite transponder bandwidth is limited,a spread spectrum separation method was proposed to increase inbound capacity.The situation of separating the spread spectrum into two and three was analyzed respectively.thus obtaining the optimal value of spreading code rate in the both cases.Simulation results show that the existing transponder bandwidth separated into two spreading spectrums can increase inbound capacity 29%,the spectrums which separated in to can increase inbound capacity 37%.