Structures and performance analysis of digital Nyquist FIR filters in indoor environment

Digital filters in communication link should be carefully designed, because small timing errors will cause serious performance degradation of the system. In this paper we reveal the details of the structures for (non-)multirate FIR filters, which are originally devised for the usage on the wireless communication link but are not limited to those specific applications. We also derive the general formulae of numerical performance, under given number representation format such as Q15, for the digital FIR filter. Unlike the case of IIR filters, the quantization of the states has the same amount of adverse effects to the quantization of coefficients in FIR filters. Finally, ASIC layouts and statistics of 1:4 interpolation FIR filter on code division multiple access (CDMA) digital cellular communication link are included.