Department of Electrical Engineering

Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

The most computationally demanding block in the digital front end of a software defined radio (SDR) receiver is the channelizer which operates at the highest sampling rate. Finite impulse response (FIR) filters are employed as channel filters in SDR receivers. These channel filters must be less complex and reconfigurable. A new reconfigurable architecture for the implementation of channel filters based on frequency response masking (FRM) technique is proposed in this paper. Our architecture offers multiple levels of reconfigurability in addition to the inherent low complexity features offered by the FRM technique. Design results show that our method offers an average adder reduction of 37% over binary subexpression elimination (BSE) technique and 57% over canonical signed digit (CSD) based techniques. © 2007 IEEE.

Proceedings - IEEE International Symposium on Circuits and Systems

Frequency response masking based reconfigurable channel filters for software radio receivers

This paper presents a novel phonocardiogram (PCG) signal compression method based on Wavelet transform. The proposed compression method uses energy based thresholding for retaining significant coefficients, uniform scalar zero zone quantizer (USZZQ) for quantizing the amplitudes of the significant coefficients and differencing coder for integer significance map (ISM). This method is tested using the PCG records taken from qdheart and eGeneralMedical databases. The performance of the compression method is assessed in terms of compression ratio (CR), percentage root mean square difference (PRD), Wavelet energy based diagnostic distortion (WEDD) measure and mean opinion score (MOS). The compression method is evaluated with PCG signals of more than 100 records with normal sounds, murmurs, stenosis, noise and other pathologies. High compression ratios with lower distortions are achieved with the proposed method.

World University root node

IET Digital Library

Wavelet energy based compression of phonocardiogram (PCG) signal for telecardiology

The most computationally demanding block in the digital front end of a software defined radio (SDR) receiver is the channelizer which operates at the highest sampling rate. Reconfigurability and low complexity are the two key requirements of the SDR channelizers. An architecture for implementing low complexity and reconfigurable finite impulse response (FIR) filters for channelizers is proposed in this paper. Our method is based on the binary common subexpression elimination (BCSE) algorithm. The proposed architecture guarantees minimum number of additions at the adder level and also at the full adder (FA) level for realizing each adder needed to implement the coefficient multipliers. The proposed architecture has been synthesized on 0.18μm CMOS technology. The synthesis results show that the proposed reconfigurable FIR filter can operate at high speed consuming minimum area and power. The average reductions in area and power are found to be 49% and 46% respectively with an average increase in speed of operation of 35% compared to other reconfigurable FIR filter architectures in literature. © 2007 IEEE.

An architecture for integrating low complexity and reconfigurability for channel filters in software defined radio receivers

Window based spatial domain two dimensional (2-D) image convolution is a widely used algorithm in many image processing applications including intrusion detection. Systolic array architectures have been widely used to implement 2-D convolvers so as to exploit the hardware parallelism on dedicated hardware platforms and thereby increase the throughput of the system. Higher levels of parallelism have not been tried for 2-D convolvers due to obvious increase in area. We propose an adaptable area-efficient parallel architecture which can be used to increase the throughput. In this paper, we study the advantages of the novel area-time efficient look-up table (LUT) based method for constant coefficient multiplication proposed in our earlier work with increasing levels of parallelism. The area reduction with this architecture increases to about 36% from 1% when the level of parallelism is increased to 8 from 1 on 0.18 um technology. Further, we also evaluate the advantages of the proposed parallel architecture. © 2007 IEEE.

ISSCS 2007 - International Symposium on Signals, Circuits and Systems, Proceedings

Adaptable area-efficient parallel architecture for grey and color image convolvers

Finite impulse response (FIR) filtering is the most computationally intensive operation in the channelizer of a software defined radio (SDR) receiver. Higher order FIR channel filters are needed in the channelizer to meet the stringent adjacent channel attenuation specifications of wireless communications standards. The computational cost of FIR filters is dominated by the complexity of the coefficient multipliers. Even though many methods for reducing the complexity of filter multipliers have been proposed in literature, these works focused on lower order filters. This paper presents a coefficient-partitioning-based binary subexpression elimination method for realizing low power FIR filters. We show that the FIR filters implemented using proposed method consume less power and achieve speed improvement compared to existing filter implementations. Design examples of the channel filters employed in the Digital Advanced Mobile Phone System (D-AMPS) and Personal Digital Cellular (PDC) receivers show that the proposed method achieved 23% average reductions of full adder and power consumption and 23.3% reduction of delay over the best existing method. ©2007 IEEE.

2007 6th International Conference on Information, Communications and Signal Processing, ICICS

Realization of low power high-speed channel filters with stringent adjacent channel attenuation specifications for software radio receivers

One of the emerging issues in telehealth care system is how effectively the limited and well established mobile technologies that are now almost globally usable are exploited. The main challenge is to develop a mobile telemedicine system to transmit biosignals directly to a specialist in an emergency medical care unit for monitoring/diagnosis using an unmodified mobile telephone which provides the patient's information on the spot without unnecessary delays in seeking care, access to health facility and provision of adequate care at the facility. To provide a practical mobile telemedicine in GSM/GPRS/EDGE/UMTS limited capacity for transmitting the cardiac data for the diagnosis of cardiovascular diseases (CVD) which are widespread health problems with unpredictable and life-threatening consequences in most regions throughout the world, the implementation of biosignals compression technique is focused in this paper. Therefore, a new and simple target data rate (TDR) driven Wavelet-threshold based cardiac signals compression algorithm is presented for mobile telemedicine applications. The performance of the compression system is assessed in terms of compression efficiency, reconstructed signal quality and coding delay. This algorithm is tested using MIT-BIH ECG databases and qdheart PCG database records and the experimental results are compared with other Wavelet based ECG coders. The presented algorithm is less complex because it does not require QRS detection, amplitude and period normalization and period sorting. © 2007 IEEE.

15th International Conference on Advanced Computing and Communications …

Wavelet-based ECG and PCG signals compression technique for mobile telemedicine

In this paper, a novel Wavelet Energy based diagnostic distortion (WEDD) measure is proposed to assess the reconstructed signal quality for ECG compression algorithms. WEDD is evaluated from the Wavelet coefficients of the original and the reconstructed ECG signals. For each ECG segment, a Wavelet energy weight vector is computed via five-level biorthogonal discrete Wavelet transform (DWT). WEDD is defined as the sum of Wavelet energy weighted percentage root mean square difference of each subband. The effectiveness of this measure is validated by linear (linear polynomial and cubic polynomial) and nonlinear (logistic) regression analysis between the computed WEDD values and the mean opinion score (MOS) given by cardiologists. WEDD provides a better prediction accuracy and exhibits a statistically better monotonic relationship with the MOS ratings than Wavelet based weighted percentage root mean square difference (PRD) measure (WWPRD), PRD and other objective measures. Standard correlation coefficient and Spearman rank-order correlation coefficient (SROCC) between the WEDD/MOS ratings is 0.969 and 0.9624, respectively. © 2007 Elsevier Ltd. All rights reserved.

Biomedical Signal Processing and Control

Wavelet energy based diagnostic distortion measure for ECG

The complexity of linear phase Finite Impulse Response (FIR) filters used in the channelizer of a software defined radio (SDR) receiver is dominated by the complexity of coefficient multipliers. It is well known that Common Subexpression Elimination (CSE) methods based on Canonical Signed Digit (CSD) coefficients produce low complexity FIR filter coefficient multipliers. A new CSE algorithm based on the binary representation of filter coefficients is presented in the paper. Design examples of channel filters employed in the Digital Advanced Mobile Phone Systems (D-AMPS) and Personal Digital Cellular (PDC) receivers show that the proposed method offers an average adder reduction of 23% over the conventional CSD-based CSE method. © 2006 IEEE.

A new common subexpression elimination algorithm for implementing low complexity FIR filters in software defined radio receivers

The most computationally demanding block of a software defined radio (SDR) receiver is the channelizer which operates at the highest sampling rate. Reconfigurability and low complexity are the two key requirements of the SDR channelizers. Two new reconfigurable architectures of low complexity finite impulse response (FIR) filters for channelizers are proposed in this paper. Our methods are based on the binary common subexpression elimination (BCSE) algorithm. The proposed architectures are capable of operating at a high speed clock frequency of 109.7 MHz based on Xilinx's Virtex II 2v2000ff896-6 FPGA for a 12-bit FIR filter coefficient. Design examples show that our method offers an average reduction of 23% in the number of addition operations compared to the conventional FIR filter implementations. © 2006 IEEE.

IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC

Reconfigurable low complexity FIR filters for software radio receivers

A new threshold based Wavelet ECG data compression method is proposed. The proposed method uses linear phase Biorthogonal 9/7 discrete Wavelet transform. Wavelet coefficients are selected based on energy packing efficiency of each subband. Significant wavelet coefficients are quantized with uniform scalar zero zone quantizer (USZZQ). Significance map is created to store the indices of the significant coefficients and this map is encoded efficiently with less number of bits by applying Huffman coding on the differences between the indices. ECG records from the MIT-BIH arrhythmia and compression test database are selected as test data. For the record 117, the proposed method achieves a compression ratio of 17.641:1 with lower percentage root mean square difference (PRD) compared to other threshold based methods. An average compression ratio of 20.8231:1 with an average PRD of 7.1641% is achieved for 19 records. The performance is better compared to the SPIHT and ASEC method for some selected records. © 2006 IEEE.