Low Complexity Decimation Filter for Multi-Standard Digital Receivers

Abstract

This paper proposes a reduction in complexity of decimation filter architectures used in multi-standard digital receiver, using IIR filters implemented as a sum of two all-pass filters. The decimation filters are an important block in devices, which want to establish communication using different standards. IIR filters are implemented on specific stages of multistage Pipeline/Interleaving structure, where high order of filters is power consuming and area demanding. Therefore, a major reduction in complexity is obtained. Regularity is an important property of all pass filters, which can be decomposed on first or second order all-pass transfer functions achieving more efficient implementation. The results presented are implemented in Pipeline/Interleaving architectures using specific decimation decomposition proposed previously [2], [3]. Reductions of 36%, 77%, and 80% are obtained compared with previous works, where basically these implementations are based on linear phase filters. The decimation filter architecture is simulated using Matlab.

Two-stage digital I/Q demodulator employing a reconfigurable 16-phase down-mixing technique

“…The lowpass decimation filter in the next section reduces the data rate. In general, since the overall complexity of the digital system is mainly due to the digital decimation filters [7], it is necessary to reduce the system requirements for the following digital filter section. Since the DSP sections are more flexible than the analog circuit sections, the digital blocks such as the digital I/Q demodulator and decimation filter can provide a reconfigurable architecture.…”

Transformation to implement computationally efficient IIR decimation filters

“…Higher order 1/N -band IIR filters show poor magnitude response and high pole sensitivity so limited value of N could be used. Tecpanecatl-Xihuitl et al [3] proposed the combination of cascaded integrator comb (CIC) filters with low pass IIR filters that were obtained from the combination of all-pass sub-filters. The comb filter design provides insufficient attenuation in stop band and distortion in pass band that has to be compensated.…”

RNS Based Programmable Multi-Mode Decimation Filter for WCDMA and WiMAX

“…The design and implementation of digital filter processors that can be used as downsamplers in wireless transceivers is detailed in [5]. A low complexity decimation filter architecture is presented in [6] by using infinite impulse response (IIR) filters implemented by all-pass sum that avoids multiplications. A low-power high linearity variable gain amplifier (VGA) that can be embedded in a multi-standard receiver that meets standard requirements is reported in [7].…”