earticle

영어

During the random access process of LTE system, PRACH needs to perform significant amount of computations (e.g. IFFT, FFT) on received signals. Therefore conducting downsampling on received signals is necessary to decrease the complexity of the subsequent signal processing work. Downsampling usually employs a multi-stage filter which consists of a CIC filter, a compensation filter and a half-band filter. This paper introduced a new donwsampling method using a multi-stage half-band filter with three half-band decimation filters. Compared with the traditional one, the new method showed a great increase in computing efficiency. The new filter was designed and a plan of implementing this filter on FPGA was suggested. MATLAB simulation was performed and the simulating results showed that the method proposed in this paper is capable of conducting downsampling on received signals, especially in the random access channel.