An Area-efficient Non-uniform Filter Bank for Low Overhead Reconfiguration of Multi-standard Software Radio Channelizers

Abstract

The channelizer in a software defined radio (SDR) base station extracts individual radio channels from the digitized wideband input signal at a very high sampling rate. The base station channelizer must be able to simultaneously extract multiple channels of non-uniform bandwidths corresponding to channel bandwidths of different communication standards. Reconfigurability and low complexity are the two key requirements in the SDR channelizer. A new reconfigurable filter bank (FB) architecture based on interpolation and masking technique for SDR channelizers is proposed in this paper. The proposed FB can be used for obtaining very narrow passband channels with extremely low complexity. Using a cascaded structure of the proposed FB, it is possible to extract channels of fractional passband widths by changing the interpolation factor. Design example shows that the proposed FB offers complexity reduction of 84% over the conventional per-channel (PC) approach. The proposed FB has been implemented and tested on Xilinx Virtex 2v3000ff1152-4 FPGA. Implementation results show that the proposed FB offers area reduction of 48.37%, speed improvement of 52.7% and power reduction of 75.9% over the PC approach.

Design of Frequency Response Masking Based Reconfigurable Filter Banks for Software Radio Channelization Using Semidefinite Programming

“…Although previous designing method can give acceptable results in applications [2][3][4], designing all the subfilters separately is an indirect way, which leads to a suboptimal solution. We therefore consider improving the design results by directly taking all desired modes into consideration.…”

“…Recently, a new reconfigurable filter bank architecture based on frequency response masking (FRM) technique was proposed for SDR channelization [2][3][4]. The FRM technique is well known for its low complexity in designing sharp transition-band finite impulse response (FIR) filters [5].…”