DSM Based low oversampling using SDR transmitter

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INTERNATIONAL JOURNAL FOR TRENDS IN ENGINEERING & TECHNOLOGY VOLUME 5 ISSUE 1 – MAY 2015 - ISSN: 2349 - 9303

DSM Based low oversampling using SDR transmitter Saranya.R Me (Vlsi Design) Department Of Ece, Vandayar Engineering College,

Mr.B.Arun M.E., Assistant Pofessor, Department Of Ece, Vandayar Engineering College,

Saranya2266ms@gmail.com

er.arunbala@gmail.com

Abstract:The oversampling recruitment is a limiting factor in high frequency application such as software defined radio. This project is a high frequency processing and low oversampling ratio. A single bit semi parallel processing is proposed in this paper. Using this single bit PDSM Architecture, high speed, high complexity computations are executed in parallel. The single bit DSM is to build an RF transmitter that includes a one bit quantifier with two level switching power amplifier for high linearity and high efficiency. Performance analysis by using the MATLAB simulations by reducing the oversampling ratio by same signal to noise ratio. The DSM implemented on field programmable gate array and using a signal code division m u lt ip le a c c e s s s ig n a l. This project will give bandwidth of the low oversampled signal increased four times without increasing frequency. Finally they can be achieved signal to noise ratio is very low and also oversampling ratio is small. Keywords— Delta sigma modulator, PDSM, SDR, oversampling. ——————————  —————————— in a DSM discourages its employment in today’s computeintensive applications, such as software defined radio (SDR) Oversampling is Sigma-Delta (S-D) modulation based systems..Software-Defined Radio (SDR) refers to the analog-to digital (A/D) conversion technology is a cost technology wherein software modules running on a generic effective alternative for high resolution (greater than 12 bits) hardware platform consisting of DSPs and general purpose converters which can be ultimately integrated on digital signal microprocessors are used to implement radio functions such as processor ICs. The increasing use of digital techniques in generation of transmitted signal (modulation) at transmitter communication and audio application has also contributed to and tuning/detection of received radio signal (demodulation) at the recent interesting cost effective high precision A/D receiver. By using the proposed low-oversampling DSM, converters. A requirement of analog-to-digital (A/D) interfaces envelope signals in wireless applications, e.g., orthogonal is compatibility with VLSI technology, in order to provide for frequency-division multiplexing (OFDM) and code division monolithic integration of both the analog and digital sections multiple access (CDMA), can be modulated to two-level on a single die. Since the S-D A/D converters are based on signals. These signals can then be amplified with a switchdigital filtering techniques, almost 90% of the die is mode power By using the proposed low-oversampling DSM, implemented in digital circuitry which enhances the prospect envelope signals in wireless applications, e.g., orthogonal of The compatibility. Additional advantages of such an frequency-division multiplexing (OFDM) and code division approach include higher reliability, increased functionality, multiple access (CDMA), multiple access (CDMA), can be and reduced chip cost. Those characteristics are commonly modulated to two- level signals. These signals can then be required in the digital signal processing environment of amplified with a switch-mode power amplifier (PA.) today. Conventional high-resolution A/D converters, such as successive approximation and flash type converters, operating at the Nyquist rate(sampling frequency approximately equal to twice the maximum frequency in the input signal), often do not make use of exceptionally high speeds achieved with a scaled VLSI technology. These Nyquist samplers require a complicated analog low pass filter (often called an antialiasing filter) to limit the maximum frequency input to A/D, and sample-and hold circuitry. On the other hand, S-D A/D converters use a low resolution A/D converter (1-bit

I.INTRODUCTION

quantizer), noise shaping, and a very high oversampling rate (64 times for the DSP56ADC16). OVERSAMPLING has become a popular technique for data conversion. The outstanding linearity of delta-sigma modulators (DSMs) is the main reason for popularity of these modulators in modern electronic components such as data converters , frequency synthesizers, and switched-mode power supplies. linearity comes at the cost of a large oversampling ratio and, therefore, need for high-speed processing. The oversampling requirement

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DSM Based low oversampling using SDR transmitter by International Journal for Trends in Engineering and Technology - Issuu