Area-efficient parallel FIR digital filter implementations

This paper presents a novel approach for implementing area-efficient parallel (block) finite impulse response (FIR) filters that require less hardware than traditional black FIR filter implementations. Parallel processing is a powerful technique because it can be used to increase the throughput of a FIR filter or reduce the power consumption of a FIR filter. However, a traditional block filter implementation causes a linear increase in the hardware cost (area) by a factor of L, the block size. In many design situations, this large hardware penalty cannot be tolerated. Therefore, it is advantageous to produce parallel FIR filter implementations that require less area than traditional block FIR filtering structures. In this paper, we propose a method to design parallel FIR filter structures that require a less-than-linear increase in the hardware cost. A novel adjacent coefficient sharing based sub-structure sharing technique is introduced and used to reduce the hardware cost of parallel FIR filters. A novel coefficient quantization technique, referred to as a maximum absolute difference (MAD) quantization process, is introduced and used to produce quantized filters with good spectrum characteristics. By using a combination of fast FIR filtering algorithms, a novel coefficient quantization process and area reduction techniques, we show that parallel FIR filtering structures with up to a 45% reduction in hardware is achieved for the given examples.