LTE-A系统中物理随机接入信道信号检测的仿真与实现

Simulation and implementation of physical random access channel signal detection in long term evolution advanced system

根据多普勒频移对物理随机接入信道(PRACH)信号检测产生的影响进行分析,划分出了中速、高速、超高速三种模式,并提出相应改进的信号检测算法。对中速模式,提出了基于频偏校正的前导检测算法;对高速模式,提出了多重滑窗峰值检测算法;对超高速模式,提出了基于整数倍子载波的频偏补偿前导检测算法。仿真结果表明,不同场景下PRACH信号通过加性高斯白噪声(AWGN)信道传输,接收端虚警率性能至少改善了3.8 d B;通过扩展典型城市信道模型(ETU)信道传输,虚警率性能至少提升了1 d B。与频域相关检测算法相比,所提算法提高了前导信号成功检测概率,减少了接入时延。

According to the influence of Doppler frequency shift on the detection of Physical Random Access Channel（ PRACH） signals, the signal detection algorithms were were divided into medium speed, high speed, ultra-high speed modes,and they were improved respectively. In the medium speed mode, a preamble detection algorithm based on frequency offset correction was proposed. In the high speed mode, an multi-sliding window peak detection algorithm was proposed. In the ultra-high speed mode, a frequency offset compensation preamble detection algorithm based on integer subcarrier was proposed. The simulation results show that, in different scenarios, when the PRACH signals are transmitted through the Additive White Gaussian Noise（ AWGN） channel, and the false alarm rate performance of the receiver is improved by at least3. 8 d B, when the PRACH signals are transmitted through the Extend Typical Urban model（ ETU） channel, the false alarm rate performance is improved by at least 1 d B. Compared with the frequency domain correlation detection algorithm, the proposed algorithms can improve the probability of successful detection of preamble signals and reduce the random access delay.