Muhammad Fasih Uddin Butt

Self-Concatenated Code Design and its Application in Power-Efficient Cooperative Communications

In this tutorial, we have focused on the design of binary self-concatenated coding schemes with the help of EXtrinsic Information Transfer (EXIT) charts and Union bound analysis. The design methodology of future iteratively decoded self-concatenated aided cooperative communication schemes is presented. In doing so, we will identify the most important milestones in the area of channel coding, concatenated coding schemes and cooperative communication systems till date and suggest future research directions.

Distributed Self-Concatenated Coding for Cooperative Communication

In this paper, we propose a power-efficient distributed binary self-concatenated coding scheme using iterative decoding (DSECCC-ID) for cooperative communications. The DSECCC-ID scheme is designed with the aid of binary extrinsic information transfer (EXIT) charts. The source node transmits self-concatenated convolutional coded (SECCC) symbols to both the relay and destination nodes during the first transmission period. The relay performs SECCC-ID decoding, where it may or may not encounter decoding errors. It then reencodes the information bits using a recursive systematic convolutional (RSC) code during the second transmission period. The resultant symbols transmitted from the source and relay nodes can be viewed as the coded symbols of a three-component parallel concatenated encoder. At the destination node, three-component DSECCC-ID decoding is performed. The EXIT chart gives us an insight into operation of the distributed coding scheme, which enables us to significantly reduce the transmit power by about 3.3 dB in signal-to-noise ratio (SNR) terms, as compared with a noncooperative SECCC-ID scheme at a bit error rate (BER) of 10-5. Finally, the proposed system is capable of performing within about 1.5 dB from the two-hop relay-aided networks capacity at a BER of 10-5, even if there may be decoding errors at the relay.

Near-Capacity Iteratively Decoded Binary Self-Concatenated Code Design Using EXIT Charts

In this treatise extrinsic information transfer (EXIT) charts are used to design binary self-concatenated convolutional codes employing iterative decoding (SECCC-ID) for communicating over both uncorrelated Rayleigh fading and additive white Gaussian noise (AWGN) channels. Recursive Systematic Convolutional (RSC) codes are selected as constituent codes, an interleaver is used for randomising the extrinsic information exchange of the constituent codes, while a puncturer assists us in increasing the achievable bandwidth efficiency. At the receiver, self-iterative decoding is invoked for exchanging extrinsic information between the hypothetical decoder components. The convergence behaviour of the decoder is analysed with the aid of bit-based EXIT charts. Finally, we propose an attractive system configuration, which is capable of operating within about 1 dB of the information-theoretic limits.

Near-capacity iterative decoding of binary self-concatenated codes using soft decision demapping and 3-D EXIT charts

In this paper 3-D Extrinsic Information Transfer (EXIT) charts are used to design binary Self-Concatenated Convolutional Codes employing Iterative Decoding (SECCC-ID), exchanging extrinsic information with the soft-decision demapper to approach the channel capacity. Recursive Systematic Convolutional (RSC) codes are selected as constituent codes, an interleaver is used for randomising the extrinsic information exchange of the constituent codes, while a puncturer helps to increase the achievable bandwidth efficiency. The convergence behaviour of the decoder is analysed with the aid of bit-based 3-D EXIT charts, for accurately calculating the operating EbN0 threshold, especially when SP based soft demapper is employed. Finally, we propose an attractive system configuration, which is capable of operating within about 1 dB from the channel capacity.

Superposition Coding Aided Bi-Directional Relay Transmission Employing Iteratively Decoded Self-Concatenated Convolutional Codes

In this paper, we consider coding schemes designed for two nodes communicating with each other with the aid of a relay node, which receives information from the two nodes in the first time slot. At the relay node we combine a powerful Superposition Coding (SPC) scheme with Iteratively-Decoded Self-Concatenated Convolutional Codes (SECCC-ID), which exchange mutual information between each other. It is assumed that decoding errors may be encountered at the relay node. The relay node then broadcasts this information in the second time slot after re-encoding it, again, using a SECCC encoder. At the destination, an amalgamated SPC-SECCC block then detects and decodes the signal either with or without the aid of a priori information. Our simulation results demonstrate that the proposed scheme is capable of reliably operating at a low BER for transmission over both AWGN and uncorrelated Rayleigh fading channels. We compare the proposed schemes performance to a direct transmission link between the two sources having the same throughput. Additionally, the SPC-SECCC system achieves a low BER even for realistic error-infested relaying.

On the Union Bounds of Self-Concatenated Convolutional Codes

In this contribution, the union bounds of self-concatenated convolutional codes (SECCCs) are derived for communications over both additive white Gaussian noise (AWGN) and uncorrelated Rayleigh fading channels. The truncated union bounds of SECCCs are very useful for studying the corresponding bit error ratio (BER) floors. Based on the truncated union bounds, various SECCCs can be designed for a desired BER floor without the need of time-consuming Monte Carlo simulations.

A feasibility study for deployment of wind energy based power production solution in Islamabad, Pakistan

This paper presents a theoretical study about the potential of power generation based on wind energy in Islamabad, Pakistan. A complete design for a wind turbine is presented with specifications about the characteristics of wind turbine to be deployed e.g. blade length, cut-in speed, rated speed, shutdown speed, hub height etc. Weather data for Islamabad Airport (year 2002-2011) is analyzed and calculations are made based on this data to determine the available wind energy and the portion of this energy that may be converted to useful power. Finally, selection of a wind turbine system, best suited to the climatic conditions of Islamabad, is made by comparing the specifications of some of the available systems in market. The goal of this paper is to highlight the potential of Islamabad in particular, and Pakistan in general, to produce electric power based on its wind energy potential.

H.264 Wireless Video Telephony Using Iteratively-Detected Binary Self-Concatenated Coding

In this contribution we propose a robust H.264 coded wireless video transmission scheme using iteratively decoded self-concatenated convolutional coding (SECCC). The proposed SECCC scheme is composed of constituent recursive systematic convolutional (RSC) codes and an interleaver is used to randomise the extrinsic information exchanged between the constituent RSC codes. Additionally, a puncturer is used to increase the achievable bandwidth efficiency. At the receiver self-iterative decoding is invoked between the hypothetical decoder components. The performance of the system was evaluated using the H.264/AVC source codec for interactive video telephony. Furthermore, EXIT charts were utilised in order to analyse the convergence behaviour of the SECCC scheme advocated. We demonstrate the efficiency of this approach by showing that the video quality is significantly improved, when using the binary SECCC scheme. More explicitly, the proposed system exhibits an

EXIT-Chart-Aided Three-Stage Concatenated Ultrawideband Time-Hopping Spread-Spectrum Impulse Radio Design

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A Review of Modern Control Strategies for Clinical Evaluation of Propofol Anesthesia Administration Employing Hypnosis Level Regulation

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