Sigma-Delta Modulation Based Digital Filter Design Techniques in FPGA

Abstract

In this paper efficient digital filter design techniques categorized as sigma-delta modulation based short word length (SWL) and multibit (or contemporary) techniques are reviewed in terms of hardware complexity, area, performance and power tradeoffs, synthesis issues, and algorithm versatility. More recent, general purpose DSP applications including classical LMS algorithms reported using sigma-delta modulation encoding are reviewed thoroughly. A small number of basic arithmetic circuits designed using sigma-delta modulation encoding and synthesized by using FPGAs are also described. Finally, recent FPGA based areaperformance-power analysis of single-bit ternary FIR filtering is discussed and compared to its corresponding multi-bit system. This work shows that in most cases single-bit ternary FIR-like filters are able to outperform their equivalent multi-bit filters in terms of area, power, and performance.

Design and Analysis of Single-bit Ternary Band-pass Digital Filter

“…These signal and noise frequency responses of the 8 th order BPSDM used to encode the Ternary tapes are individually exposed in figure 4.4 and figure 4.5. The values for the constants are used as [6]: To verify the NTF of the 8 th order BPSDM, a simulation was undertaken in which a low power white noise signal was input to the BPSDM and resultant spectra were obtained the graph in figure 4 At this point the introduced gain by Ternary filter can be removed by multiplying the filter output before remodulation by the inverse gain denoted by C in figure 3.2. This factor reduces the amplitude of the input to the signal with a level which will not overload the chosen SDM used in the re-quantization process [6].…”

“…The values for the constants are used as [6]: To verify the NTF of the 8 th order BPSDM, a simulation was undertaken in which a low power white noise signal was input to the BPSDM and resultant spectra were obtained the graph in figure 4 At this point the introduced gain by Ternary filter can be removed by multiplying the filter output before remodulation by the inverse gain denoted by C in figure 3.2. This factor reduces the amplitude of the input to the signal with a level which will not overload the chosen SDM used in the re-quantization process [6]. The re-quantization to the single-bit filtering domain of filtered signal requires usage of SD modulator that acquire SQNR greater than the stop band attenuation of the Ternary filter and also have greater bandwidth than the passband of Ternary filter.…”

“…In [2,3], mathematical model of low pas filter has been developed to guess the required performance results in stop band attenuation at worst. Furthermore, well-organized filtering of innovative bit-stream configuration is anticipated in [4]*, and Exploration of ternary FIR-filter at diverse oversampling-ratio and acquired the result in MATLAB that indicated the influence on the structure and enactment of stable ternary-FIR filter in terms of stop-band attenuation and also estimate the area performance-tradeoff at diverse oversampling-ratio thru created were stated in [5] and in [6] which revealed the contrast of sigma-delta modulation founded short word length & multi bit techniques. In this paper we considered the sigma-delta modulation-based ternary bandpass-like digital filter via FFT interpolation techniques at diverse oversampling-ratio and compared the result to multi-bit bandpass digital filter in terms of stop band-attenuation.…”

A Novel Approach Toward Algorithm Architecture Co-Optimization for the Application of Adaptive Noise Cancellation for Wireless Communication

“…Sometimes, the algorithm and architecture co-optimization makes the design even more compact [3]. One of the latest methods of resource reduction in ASIC or or partially transformed to single-bit) [8][9][10][11][12][13][14][15], IIR filters [16][17][18], and some complex adaptive filter structures [19][20][21][22]. Other recent examples of SDM-based short word length systems include adaptive channel equalizers using a µless approach [23], Weiner filters [24], Matched filters [25], digital arithmetic units [26], smart sensor communications [27], correlation-less filters [28,29] and latest SDM-Based Image Processing [30].…”

Analysis of Booth Multiplier based Conventional and Short Word Length FIR Filter

“…One way to carry out these implementations effectively is; to reduce the word length that will increase throughput in view of that. In a few decades, the SDM technique has broaden its domain of applications, from being used in analog to digital convertor to very complex DSP system design [4].The SSDM is a specific method to convert low-bandwidth signals into a digital data stream [5]. This is key element in developing single-bit processing algorithms [6].…”