码间干扰效应对I-UWB频谱效率的限制作用

对于脉冲超宽带(I-UWB)系统,随着传输速率的提高而增强的码间干扰致使误码率恶化,限制了可实现的最高速率,从而降低了频谱效率。作者分析了码间干扰对I-UWB频谱效率的限制作用。首先推导了I-UWB的码间干扰估算公式,然后仿真了在IEEE定义的4种信道模式下,随着传输速率的增加码间干扰对误码率的恶化作用。结果表明,如果要求未编码的误码率不高于千分之一,由于码间干扰效应,系统可实现的最大传输速率远小于传输带宽所允许的最大速率,当采用二阶高斯脉冲时最高频谱效率只有带宽的百分之几。

Limit effect of inter chip interference on I-UWB bandwidth efficiency

Inter chip interference(ICI) will increase when transmission rate of an impulse ultra wide band(I-UWB) system is getting larger,which will worsen symbol error rate(SER),restrict the highest realizable transmission rate,and reduce bandwidth efficiency.In order to understand the problem,the limit effect of ICI on the bandwidth efficiency of I-UWB was analyzed.The estimation formula of ICI for I-UWB was derived with the simulation of the worsening impact on SER with the transmission rate increase under four channel modes defined by IEEE.The simulation results show that if required uncoded SER is less than one in a thousand,the realizable maximum transmission rate of the system is much lower than the transmission bandwidth allowed maximum rate due to this ICI effect.And the maximum bandwidth efficiency is a few percent when using second Gauss pulse.