A High-Performance FIR Filter Architecture for Fixed and Reconfigurable Applications
Transpose form finite-impulse response (FIR) filters are inherently pipelined and support multiple constant multiplications (MCM) technique that results in significant saving of computation. However, transpose form configuration does not directly support the block processing unlike direct form configuration. In this paper, we explore the possibility of realization of block FIR filter in transpose form configuration for area-delay efficient realization of large order FIR filters for both fixed and reconfigurable applications. Based on a detailed computational analysis of transpose form configuration of FIR filter, we have derived a flow graph for transpose form block FIR filter with optimized register complexity. A generalized block formulation is presented for transpose form FIR filter. We have derived a general multiplier-based architecture for the proposed transpose form block filter for reconfigurable
applications. A low-complexity design using the MCM scheme is also presented for the block implementation of fixed FIR filters. The proposed structure involves significantly less areadelay
product (ADP) and less energy per sample (EPS) than the existing block implementation of direct-form structure for medium or large filter lengths, while for the short-length filters, the block implementation of direct-form FIR structure has less ADP and less EPS than the proposed structure. Application specific integrated circuit synthesis result shows that the proposed structure for block size 4 and filter length 64 involves 42% less ADP and 40% less EPS than the best available FIR filter structure proposed for reconfigurable applications. For the same filter length and the same block size, the proposed structure involves 13% less ADP and 12.8% less EPS than that of the existing direct-form block FIR structure.
FINITE-IMPULSE response (FIR) digital filter is widely used in several digital signal processing applications, such as speech processing, loud speaker equalization, echo cancellation, adaptive noise cancellation, and various communication applications, including software-defined radio (SDR) and so on . Many of these applications require FIR filters of large order to meet the stringent frequency specifications –. Very often these filters need to support high sampling rate for high-speed digital communication . The number of multiplications and additions required for each filter output, however, increases linearly with the filter order. Since there isno redundant computation available in the FIR filter algorithm, real-time implementation of a large order FIR filter in a resource constrained environment is a challenging task. Filter coefficients very often remain constant and known a priori in signal processing applications.
In this paper, we explore the possibility of realization of block FIR filter in transpose form configuration in order to take advantage of the MCM schemes and the inherent pipelining for area-delay efficient realization of large order FIR filters for both fixed and reconfigurable applications. The main contributions of this paper are as follows.
1) Computational analysis of transpose form configuration of FIR filter and derivation of flow graph for transpose form block FIR filter with reduced register complexity.
2) Block formulation for transpose form FIR filter.
3) Design of transpose form block filter for reconfigurable applications.
4) A low-complexity design method using MCM scheme for the block implementation of fixed FIR filters.