G. Vidhya Sagar

Bio: G. Vidhya Sagar is an academic researcher from VIT University. The author has contributed to research in topics: Communications system & Time division multiple access. The author has co-authored 4 publications.

Performance analysis of a hybrid multiple access technique in LTE system

Abstract: In this paper we emphasis the effect of the variation of major parameters on Orthogonal Frequency Division Multiple Access (OFDMA) systems and the evaluation of channel estimation and equalization are made, in which the bit/symbol error rate of a time varying channel has to be estimated in order to correct the channel interference prior to the decoding of information symbols. We evaluated the channel capacity to quantify the potential of OFDMA and Code Division Multiple Access (CDMA) to improve the performance of the overall system. With the advantages of CDMA and OFDMA, a new multiple access technique has been developed called Coded-OFDMA(C-OFDMA) Multiple Access, which provides more dominant and robust, superiority and greatly improves the performance. Reuse partitioning of Hybrid Multiple Access(HMA) increases the system capacity. Simulation results show that the proposal is more effective, feasible and yields improved results.

Efficient Neighbour Cell Detection in LTE Systems

Abstract: This paper provides more prominence for the eNodeB to use reliable and robust algorithm for self configuration of the Neighbor Cell List (NCL). The novel NCL selection scheme is based on Potentially Worst case Carrier to Interference (PWCI) which, in contrast is more promising than the conventional Receive Signal Strength Indicator (RSSI) based cell identity detection of neighbor cells that maximizes the performance of the system. The proposed scheme utilizes the PWCI as a threshold for neighbor cell ID detection under high noise and interference scenario rather than the empirically generated RSSI threshold. Simulation results shows that proposed self configured NCL detection improves the performance rate by 7% and achieves the probability of right cell ID detection around 85% under noisy environment, moreover the success rate for the cell ID detection for fixed time offset and carrier frequency oscillation(CFO) at different cases also improved by about 20% based on the existing scheme.

Spectral Analysis and Comparison of Single-Carrier PLC Modules in Narrowband Power Line Communication System

Abstract: In recent times, power line communication (PLC) has an ability of communicating the signals and messages making use of the existing power lines without going for new mediums such as optical fibers or radio waves. Considering the voltage, electrical networks are rated as low (1 kV), medium (1–100 kV), and high (>100 kV) networks and the communication problems in these networks increase with increase in voltage. In order to establish high-speed data communications with data rates in the range of megabit/s over power line networks, dedicated communication systems considering the hostile channel properties are required. In addition to signal distortion, losses in cables and multipath propagation, noise from the system also plays a key role to alter the digital communication over power line networks which is dealt in this project. In this work, the signals are obtained with less bit error rate (BER) using Rayleigh fading channel improving the efficiency of the whole system. Different modulation techniques are compared in narrowband power line communication (PLC) systems, and some suggestions are made for the improvement of data transmission in narrowband systems. The best compromise for single-carrier PLC modules between efficiency and architecture complexity is being investigated in this project.