Pass Finite Impulse Response Filter Research Articles

High speed energy efficient multiplier for signal processing

In digital signal processors, computation intensive arithmetic functions such as image smoothing, convolution and filtering frequently involve multiplication-based operations like inner-product generation and accumulation. Multiplication time is the predominate element in determining the execution time of any digital signal processing chip. Switching activity of the functional units in the multiplier contributes to significant amount of power dissipation. This paper presents high speed energy efficient multiplier. By reducing the switching activity and number of computations, the proposed multiplier achieves a better performance in terms of delay and PDP. The proposed high speed energy efficient multiplier is designed using Verilog-HDL and synthesised using Cadence RTL compiler with respect to 180 nm and 90 nm technological libraries. The proposed multiplier shows the delay reduction of 8.95% to 31.40%. The potential benefit of reducing the delay realises a PDP reduction of 13.66% to 26.95%. The performance of the proposed multiplier is verified by implementing it in 16 tap 16-bit coefficient band pass finite impulse response filter. The multiplier used here can be used in signal processing application to obtain energy efficient hardware.

Frequency response masking based FIR filter using approximate multiplier for bio-medical applications

The advancements in medical healthcare networks and bio-medical sensor technologies enabled the use of wearable and body implantable intelligent devices for healthcare monitoring. These battery-operated devices must be capable of very low power operation for ensuring long battery life and also to prevent intense radiations. The major power consuming part of these devices are the multipliers built into the digital filters for performing signal processing operations. This paper proposes a low power signed approximate multiplier architecture for bio-medical signal processing applications. The circuit characteristics and error metrics of the proposed multiplier are estimated to verify its performance advantage over other approximate multipliers. In order to validate the efficacy of the approximate multiplier in real time signal processing applications, a band pass finite impulse response filter (FIR) filter is designed using frequency response masking technique and used in the Pan Tompkins method for the extraction of QRS complex from raw ECG data. The sensitivity, positive predictivity, and detection error rate of the QRS detection method are estimated and the results show that the approximate filtering method implemented gives a comparable performance as that of exact methods.