窄带干扰情况下定时序列检测性能分析

Analysis of the Narrowband Interference Effect on Timing Sequence Detection Performance

分析了多载波系统在窄带干扰情况下定时测度的统计特性,根据定时测度的概率密度分布特性,得到了定时序列的漏警概率和虚警概率.研究结果显示,一般情况下,信干比(SIR)对定时估计性能影响不大,当SIR较高时(大于10 dB),噪声是影响估计性能的关键因素.对于一个给定值的SIR,干扰带宽对定时测度的均值和方差几乎没有影响.当SIR小于15 dB时,训练序列的漏警概率受窄带干扰(NBI)影响较大,虚警概率与信噪比(SNR)和SIR无关,且近似为零.该结果对定时同步算法的研究和定时序列检测都具有一定的参考价值.

The statistical property of timing metric is analyzed in the presence of narrowband interference. The missing and false detection probabilities of training sequence are addressed according to the probability distributions of timing metric. It is shown that the performance of timing metric estimation can not be influenced by signal to interference ratio （SIR）. In normal condition, the noise is the key factor which affects estimation performance when SIR is high（higher than 10 dB）. The mean and the variance of timing metric is hardly affected by jamming bandwidth in a given SIR. The missing detection probability of training sequence, affected by narrowband interference （NBI）, becomes high when SIR is lower than 15 dB. The false detection probability is not related to signal-to-noise ratio （SNR） and SIR.