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Hardware implementation of WiMAX systems using field programmable gate array (FPGA) technology is a very important task for mobile communication and wireless network researchers. As a first step, a careful simulation of the system performance has been done using the simulation link platform of matlab_2009. The performance of the simulated system was evaluated using the bit-error-rate (BER). In this...
Both orthogonal frequency division multiplexing (OFDM) and single-carrier (SC) with frequency division multiple access (FDMA) have been regarded as a possible solution for improving the performance of future generation wireless communication systems. OFDM can better exploit the frequency diversity gain while SC-FDMA is less sensitivity to non-linearity of amplifier with lower peak-to-average power...
In this paper, we study the performance of an Orthogonal Frequency Division Multiplexing (OFDM) WiMAX transmission system with adaptive modulation and coding (AMC) over different fading channels. An explanation necessary to understand the block diagram of the system is briefly given and a MATLAB code is written to simulate the basic processing involved in this system. The simulation is performed for...
OFDMA-based IEEE802.16 implements among other features adaptive modulation and coding (AMC) which results in a different bit rate for each user depending on its position in the cell as well as the radio condition it experiences; users away from the base station experience lower throughput. In case of (intra-cell) mobility, the download time for the data user will thus depend on the different locations...
Adaptive modulation enables a WiMAX system to optimize the throughput based on propagation conditions. IEEE 802.16 (WiMAX) system support BPSK, QPSK, 16-QAM and 64-QAM and the access scheme is OFDM. This paper presents the performance of different variants of transmission control protocols with different modulation schemes when density of mobile nodes changes.
Orthogonal frequency division multiplexing (OFDM) is the modulation scheme of choice for digital video broadcasting-handheld (DVB-H), which is required to operate under high mobility conditions resulting in significant Inter-carrier Interference (ICI). To mitigate ICI, several cancellation schemes have been proposed but they require reliable channel information at the receiver which is quite challenging...
In this paper, we consider a new channel probing scheme for opportunistic scheduling in the uplink of orthogonal frequency division multiplexing (OFDM)-based wireless systems. To reduce signaling overhead for the probing, we consider a two-step channel probing process; called pre-probing and mainprobing. Good subchannels are first estimated through the pre-probing process using a probing signal transmitted...
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