Muhammad Imadur Rahman

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This paper investigates the feasibility and broad implications of the use of 3GPP LTE systems in license-exempt situations. License-exempt use can occur in traditional unlicensed bands or in secondary usage of white space spectrum. Various scenarios for license-exempt use are listed with a particular focus on spectrum access as a secondary user. Regulatory(More)
The impact of non linear distortion due to High Power Amplifier (HPA) on the performance of Link Adaptation (LA) Orthogonal Frequency Division Multiplexing (OFDM) based wireless system is analyzed. The performance of both Forward Error Control Coding (FEC) en-coded and uncoded system is evaluated. LA maximizes the throughput while maintaining a required(More)
In an Orthogonal Frequency Division Multiplexing (OFDM) system, downlink beamforming can be implemented either before IDFT (frequency domain) or after IDFT (time domain) module in a base station transmitter. We denote the former scheme as PreIDFT downlink beamforming, and the latter as Post-IDFT downlink beamforming. In this work, we have compared Pre-IDFT(More)
The cyclic delay diversity is applied in OFDM receiver to increase the frequency-selectivity of the channel seen at the receiver for flat (or less frequency-selective) channels. The diversity combining is performed prior to the Discrete Fourier Transform (DFT) operation. A new method has been studied to optimize the Pre-DFT diversity combining by selecting(More)
In this paper we advocate cross–layer optimization over the whole ISO/OSI protocol stack. As an example we refer to a system using multiple description coding at application layer combined with orthogonal frequency division multiplexing at the link level to provide robustness against hostile wireless channels. In the proposed optimization design negotiation(More)