摘要
3Gpp长期演进(long term evolution,LTE)技术中主同步信号是一组复小数序列,这使得子帧同步的运算量非常大。介绍了主同步信号的构成,分析了同步信道滤波器对子帧同步性能的影响。提出了通过量化近似本地主同步信号以减少LTE子帧同步运算量的方法,并在AWGN(additive white guassian noise)和LTE标准中的EVA(extended vehicular a model)多径信道环境下对此方法进行了仿真。仿真表明量化本地主同步信号不会影响小区主同步码号的识别,对FFT窗定时检测性能影响也非常小。通过运算复杂度分析,当把本地主同步信号量化为2bit后,该方法所需乘法和加法次数较量化本地主同步信号前分别降低约98.8%和70.3%。在不同信噪比和载波频偏环境下的仿真结果表明该低复杂度子帧同步方案可应用于信噪比大于0,初始载波频偏小于4 kHz,最大多普勒频移小于100 Hz的环境中。最后在FPGA上对此低复杂度子帧同步方法进行了实现,并成功应用于TDD-LTE扫频仪中。
The Prime Synchronization Signal （PSS） of Long Term Evolution （LTE） is made up of three complex decimal sequences, which makes the sub-frame synchronization has high computation complexity. The PSS sequences are introduced and the effect of synchronization channel filter on the sub-frame synchronization performance is analyzed in this paper. A scheme to reduce the computation complexity of the LTE sub-frame synchronization is proposed via quan- tizing the local replicas of PSS sequences. The simulation results under AWGN （Additive White Gaussian Noise） channel model and EVA （Extended Vehicular A model） multi-path model show that this scheme has no effect on the PSS identifi- cation and only little effect on the performance of FFT window position detection. Through computation complexity analysis, it is proved that multiplication times and addition times decline 98.8 percent and 70.3 percent, respectively, when the local replicas of PSS sequences are quantized into two bits. The simulation results in different signal to noise ratio and carrier frequency offset situation show that this low complexity sub-frame synchronization method is applicable in the scenario where the initial carrier frequency offset and maximum Doppler shift are less than 4 kHz and 100 Hz, respec- tively, when the signal to noise ratio is beyond 0 dB. This low complexity sub-frame synchronization scheme is realized in FPGA and also successfully applied in the TDD-LTE scanning receiver.
出处
《电子测量与仪器学报》
CSCD
2012年第4期344-351,共8页
Journal of Electronic Measurement and Instrumentation
关键词
长期演进
子帧同步
主同步信号
小区搜索
扫频仪
LTE
sub-frame synchronization
primary synchronization signal
cell search
scanning receiver
