M. Salim Beg

Design and implementation of BPSK transmitter and receiver for Software Defined Radio on a Model Based Development Platform

This paper describes the design, development and implementation of Binary Phase Shift Keying Transmitter and Receiver for Software Defined Radio on a Model Based Development Platform. Model Based Development reduces the system design considerably as compared to conventional method. Advanced system design concepts including simulation, code generation and implementation / testing is presented. Software Defined Radio based framework which will be performing data processing task at the baseband stage is presented.

Design and implementation of Forward Error Correction in Software Defined Radio on a Model Based Development platform

Forward Error Correction (FEC) plays an important role in todays Digital Communications Systems. This paper describes the design and implementation of the FEC, the (8,4) Block Coder and 8×8 Interleaver in a Binary Phase Shift Keying Transceiver on a Model Based Development platform for a Software Defined Radio (SDR) system. Model Based Development is a new development process where the model of the communications systems is designed and developed in software such as Simulink / Matlab. Model Based Development process saves considerable amount of time in the form of design, implementation and testing.

Thresholds: Performance Evaluation for APSSNMP: An Alternative Security Algorithm for SNMP

Simple Network Management Protocol versions 1 and 2 (SNMPv1 and SNMPv2c) have only a trivial security mechanism [1]. The security implementation of SNMPv1 and SNMPv2c is based on the community system where a community name functions both as a password for authentication and access control system. However, due to the simplistic design of the system, the community name is sent as plain-text over the network. This might have been acceptable if implemented solely on a trusted local area network, but today’s networks are widely distributed and are linked via many bridges and routers that might be exposed to eavesdropping. Therefore, the security for SNMPv1 and SNMPv2 is impractical in a large and exposed network. SNMPv3 addressed the security issue that was limiting the previous two versions [2, 3] but the implementation is complex and requires a significant change in the design of the agent and manager. There is already a large deployed base of SNMPv1 and SNMPv2 systems and it would be difficult to upgrade these systems to SNMPv3. This is reflected in the low deployment rate of SNMPv3 to date.

A Dynamically Reconfigurable Transceiver for Software Defined Radio

Defined Radio (SDR) is an emerging field in the area of Digital Communications. The ever growing interest in SDR systems lies in the fact that it can provide multi-standard architecture. This paper describes a dynamically reconfigurable architecture of an SDR system on a Model Based Development (MBD) platform which is a new approach and saves a considerable amount of time in design, testing and implementation. In this work, four modulation schemes are chosen for this application of SDR namely BPSK, QPSK, 16-QAM, 256-QAM. The paper describes the implementation of these four modulation / demodulation schemes on an MBD platform. The receiver in this architecture is made intelligent enough to determine which modulation scheme the transmitter is transmitting and switches on to the corresponding demodulation scheme. Finally the results obtained are presented in graphical form.

Bluetooth based implementations for realising new consumer systems

Bluetooth based new wireless applications can increase comfort and security by automation of the tasks earlier controlled manually. In this paper advantages of low cost, low power and robustness of Bluetooth have been exploited to propose and implement two new consumer systems in the form of a garage door opening system and an electronic attendance record system. Both the applications provide luxury of automation along with promise of a better security system and will thus be a step towards realization of a smart building environment. Bluetooth based garage door opening system helps to overcome the inconvenience to move out of the car for unlocking the door and it provides the luxury of keyless opening which is electronically controlled just by enabling the authenticated Bluetooth slave device. The other Bluetooth based application proposed and implemented in this work relates to automatic monitoring and recording of attendance of employees in an organization. Both the applications proposed and implemented in this paper offer better security, higher flexibility and lesser complexity. In this paper the applications are developed based on Bluetooth Link using Host Controller Interface and Asynchronous Connection Less (ACL) link.

OFDM transceiver for software defined radio on a model based development platform

Orthogonal Frequency Division Multiplexing (OFDM) is an efficient multiplexing technique which is being used in many wireless communication systems. This paper describes a simple OFDM transceiver where the QPSK mapping / demapping is used and an 8-point complex IDFT/DFT blocks used for Software Defined Radio (SDR). The whole system is designed, developed and tested on a model based development platform on which design, development and testing saves considerable amount of time compared to traditional design method.

Improving TCP Performance based on Fuzzy-Logic for Mobile Ad hoc Networks

Transmission Control Protocol (TCP) is designed for wired networks and the sender assumes that packet loss is an indicator of network congestion. However, this assumption may not apply to Mobile Ad hoc Networks (MANETs). Numerous transmission control protocols have been proposed in the literature to address the problem of congestion in MANETs. Their performance is highly dependent on networks conditions, probe and explicit notification messages. This paper proposed a fuzzy logic based inference system based on the factors of expected throughput and actual throughput to dynamically adjust the congestion window size to improve the performance of TCP in MANETs. Fuzzy inference system is an attractive approach used in MANETs which suffer from all kinds of uncertainty, randomness and vagueness. The scheme does not rely on any explicit feedback from the network and requires only sender side modifications. The simulation study examine the throughput, fairness index degree, packet loss percentage and packet delay as performance metrics of the ad hoc network with regard to equal sharing of network bandwidth among multiple TCP flows. The results observe that the proposed scheme achieves the desired goals of performance improvement in terms of packet loss and packet delay compared to TCP-Vegas, Reno and New Reno.

Design And Implementation of Gas Turbine Combustion Chamber Control System Based on Wireless Sensor Network

Wireless Sensor Networks (WSNs) are increasingly being used in various applications such as for controlling & monitoring purposes in industrial processes. Cost effectiveness is the highly prioritized goal of communication protocols & application design for WSN. This paper discusses the development of a WSN to control & monitor Gas Turbine (GT) based Combustion Chamber (CC), which includes the design, development & implementation of a WSN for real time monitoring & controlling GT based combustion chamber system. The motive behind this work is to totally eliminate the use of control cables. It may be visualized that the sensors are placed around the periphery of the CC of the GT. The regulation of pressure & temperature is done using a radio module attached to a data acquisition board and the prototype circuits designed. Programming of the sensor nodes and the gateway is done using software. The prototype system developed is based on 2/3 voting logic for tripping the system if the temperature or pressure goes below or beyond the threshold range. This work is an initiative to save control cable costs to make gas-based power plants cost effective since no such approach has been taken regarding WSN application until now.

Design and testing of a Software Defined Radio based transceiver on a Graphics Processing Unit

High transmission bit rate in wireless channels gives rise to severe inter-symbol interference (ISI) and this makes the detection task very challenging. In such cases, Near-Maximum-Likelihood (NML) detection gives good performance. This paper describes the Design and Testing of a QPSK transceiver using NML detection on an NVIDIA Graphics Processing Unit (GPU) for Software Defined Radio (SDR) systems. Recent advances in programmable, highly parallel GPUs have enabled high performance general purpose computation. NVIDIA GPU is used for realizing this application. The data is transmitted over a frequency selective channel and experimental results are obtained. All the processing is done onto the NVIDIA GPU and the results obtained are compared for varying Signal to Noise Ratios (SNR) for different channel configurations.

FL-TCP: A fuzzy logic based scheme to improve TCP performance in MANETs

Transmission Control protocol has been essentially designed for wired networks, and its performance is not good for wireless networks. The objective of the present work is therefore to study a fuzzy based inference system based on the factors of expected throughput and actual throughput to dynamically adjust the congestion window size to improve the performance of TCP in Mobile Ad hoc Networks (MANETs). Our scheme does not rely on any explicit feedback from the network and requires only sender side modifications. In our simulation study we examine the throughput and packet delay as performance metrics of the ad hoc network with regard to equal sharing of network bandwidth among multiple TCP flows. Through extensive simulations we show that the number of concurrent flows significantly affects the TCP performance metrics and our proposed scheme achieves the desired goals of performance improvement compared to other TCP variants.