NOVATEUR PUBLICATIONS International Journal of Research Publications in Engineering and Technology [IJRPET] ISSN: 2454-7875 VOLUME 3, ISSUE 7, July-2017
OPTIMIZED SNR FOR INTERSYMBOL INTERFERENCE REDUCTION OVER MODIFIED DFZF EQUALIZER FOR PACKET ERASURE NETWORK ARJUN GHULE Research Scholar, Department of ECE, Jawaharlal Nehru Technological University, Kukatpally, Hyderabad, India DR. PRABHU BENAKOP Principal, Indur Institute of Engineering & Technology, Siddipet, Telangana, India ABSTRACT: A novel technique presented in this paper is used to find an optimal signal to noise ratio (SNR) for maximizing overall data throughput and system performance for Automatic speech Recognition (ASR) applications. In speech data transmission over communication channels inter symbol Interference (ISI) will occur. In this paper the major problem faced while implementation is loss of data due to inter symbol Interference. By changing multiplying factor at feedback filter coefficients & Optimizing the signal to noise ratio, receiver errors can be minimized. DFZFE is used to combat ISI in wireless channels. In literature, purpose of designing the feed forward equalizer in the channel is treated linear. .A drawback of this method is error propagation due to the feedback.[15]. Feedback angle is found to maximize the output signal-to-noise ratio (SNR) [17]. Algorithm that achieves the same equalization performances at a reduced complexity are used [18]. Inter symbol Interference problem is faced in many applications such as cognitive radio, robotics, and sensor networks [19] KEYWORDS: Data communication, system performance, Intersymbol Interference (ISI), interference constraints, degradation, Signal to Noise Ratio(SNR) , Decentralized feedback zero forcing equalizer (DFZFE): Automatic speech Recognition(ASR) etc. INTRODUCTION: In literature it is suggested that data accuracy can be comprised because the loss due to absence of optimal feedback, as well as the gain obtained from limited feedback with local channel knowledge compared to preceding without feedback [16].In this paper optimized SNR and feedback filter coefficients are recommended at Decentralized feedback zero forcing equalizer (DFZFE) DECENTRALIZED FEEDBACK ZERO FORCING EQUALIZER (DFZFE): This technique is widely used in combat internal interference [1]. It is used to combat (inter symbol
interference) ISI in wireless channels [2]. Codes are designed in such a way that, it will generate random symbols that which will be sent through a channel with ISI (inter symbol interference) with AWG noise [3]. Then in Next step DFZFE is applied to for decoding.
Fig. No.1. Typical DFZFE system The main cause of inter symbol interference is time depressiveness the signal environment [4]. E.g. multipath scattering environment, delayed versions of a symbol transmission is received at receiver end this may lead to interference with other symbols transmission. IMPLEMENTED ALGORITHM: Defining length of transmitting sequence. Convolution of channel impulse response with transmitting sequence. Addition of SNR. Modified filter with Multiplication factor of half & one fourth. Computing Inverse impulse Response. Hard decision decoding. RESULTS & DISCUSSION: ZF DFE solution and as such can be viewed as a generalization of an existing work. We demonstrate the effectiveness of the proposed solution through simulation [20] for zero-forcing decision feedback equalization (ZF-DFE) on fast fading channels. We present an error propagation framework in ZF-DFE [21]
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