25 research outputs found
Multi-standard programmable baseband modulator for next generation wireless communication
Considerable research has taken place in recent times in the area of
parameterization of software defined radio (SDR) architecture. Parameterization
decreases the size of the software to be downloaded and also limits the
hardware reconfiguration time. The present paper is based on the design and
development of a programmable baseband modulator that perform the QPSK
modulation schemes and as well as its other three commonly used variants to
satisfy the requirement of several established 2G and 3G wireless communication
standards. The proposed design has been shown to be capable of operating at a
maximum data rate of 77 Mbps on Xilinx Virtex 2-Pro University field
programmable gate array (FPGA) board. The pulse shaping root raised cosine
(RRC) filter has been implemented using distributed arithmetic (DA) technique
in the present work in order to reduce the computational complexity, and to
achieve appropriate power reduction and enhanced throughput. The designed
multiplier-less programmable 32-tap FIR-based RRC filter has been found to
withstand a peak inter-symbol interference (ISI) distortion of -41 dB
Intelligent Wireless Sensor Nodes for Human Footstep Sound Classification for Security Application
Sensor nodes present in a wireless sensor network (WSN) for security
surveillance applications should preferably be small, energy-efficient and
inexpensive with on-sensor computational abilities. An appropriate data
processing scheme in the sensor node can help in reducing the power dissipation
of the transceiver through compression of information to be communicated. In
this paper, authors have attempted a simulation-based study of human footstep
sound classification in natural surroundings using simple time-domain features.
We used a spiking neural network (SNN), a computationally low weight
classifier, derived from an artificial neural network (ANN), for
classification. A classification accuracy greater than 85% is achieved using an
SNN, degradation of ~5% as compared to ANN. The SNN scheme, along with the
required feature extraction scheme, can be amenable to low power sub-threshold
analog implementation. Results show that all analog implementation of the
proposed SNN scheme can achieve significant power savings over the digital
implementation of the same computing scheme and also over other conventional
digital architectures using frequency-domain feature extraction and ANN-based
classification.Comment: 12 pages, Journa
A New High-Performance Digital FM Modulator and Demodulator for Software-Defined Radio and Its FPGA Implementation
This paper deals with an FPGA implementation of a high performance FM modulator and demodulator for software defined radio (SDR) system. The individual component of proposed FM modulator and demodulator has been optimized in such a way that the overall design consists of a high-speed, area optimized and low-power features. The modulator and demodulator contain an optimized direct digital frequency synthesizer (DDFS) based on quarter-wave symmetry technique for generating the carrier frequency with spurious free dynamic range (SFDR) of more than 64 dB. The FM modulator uses pipelined version of the DDFS to support the up conversion in the digital domain. The proposed FM modulator and demodulator has been implemented and tested using XC2VP30-7ff896 FPGA as a target device and can operate at a maximum frequency of 334.5 MHz and 131 MHz involving around 1.93 K and 6.4 K equivalent gates for FM modulator and FM demodulator respectively. After applying a 10 KHz triangular wave input and by setting the system clock frequency to 100 MHz using Xpower the power has been calculated. The FM modulator consumes 107.67 mW power while FM demodulator consumes 108.67 mW power for the same input running at same data rate