一种基于PN累积自相关的DTMB频谱感知新算法

A Novel Spectrum Sensing Algorithm for DTMB Systems Based on PN Accumulated Autocorrelation

针对数字电视地面广播传输标准(DTMB)的频谱感知问题,提出了一种新的基于DTMB信号帧中伪随机(PN)序列累积自相关的频谱感知算法。所提算法的创新性在于通过联合多个不同相关间隔的累积自相关结果作为频谱感知的检验统计量,充分利用了有限频谱感知时间内的信号信息。仿真结果表明,当把感知时间设为50 ms时,为了确保频谱感知检测的虚警概率和漏验概率都低于0.01,针对DTMB信号的3种帧头模式,所提算法所需的信噪比分别为-20.5 dB、-21 dB和-22 dB,优于已有的频谱感知算法。此外,仿真结果还表明载波频偏和多径衰落对所提算法的性能几乎没有影响。

Spectrum sensing algorithm based on accumulated pseudo-noise sequence autocorrelation （ PNAC） for Digital Terrestrial Multimedia Broadcast（ DTMB） systems is proposed in this paper. To make full use of the information within the limited spectrum sensing time, the decision statistic is obtained by combining accumulated autocorrelations with different interval values together. Simulation results show that when spectrum sensing time is set to 50 ms,to make sure that the false alarm probability and the miss-de-tection probability are both under 0. 01,the required signal-to-noise ratio（SNR） values of proposed algo-rithm are -20. 5 dB,-21 dB and -22 dB,for three frame header modes,respectively. The performance of proposed algorithm is better than that of existing spectrum sensing algorithms. Meanwhile the proposed al-gorithm is robust to both carrier frequency offset and multipath fading.