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This paper presents the analysis of the throughput enhancements using threshold-based PUSC in WiMAX OFDMA system. We consider a point-to-multipoint (PMP) WiMAX network where base station (BS) schedules downlink packets for simultaneous transmissions to multiple users. Using the OFDMA option in the WiMAX standard, users are assigned different subchannels for reception of their data using the same OFDM...
In current wireless standards like 3GPP LTE or IEEE 802.16 / WiMAX multiple access is based on orthogonal signalling using single-carrier frequency-division multiple access (SC-FDMA) or orthogonal frequency-division multiple access (OFDMA). Links between a base station and different terminals use mutually orthogonal radio resources. This paper studies potential gains in average cell throughput by...
In the recent years, the WiMAX cellular system has been greatly deployed worldwide as it can provide high data rate to mobile subscribers. However, a few works has been done to characterize the behavior of the WiMAX network in different deployment scenarios. In this paper, we investigate the performance of the WiMAX system in various morphological scenarios, namely, dense urban, urban, and sub-urban...
In the context of micro and macro-mobility capabilities defined by IEEE 802.16e/WiMAX standards, the paper presents the simulation campaign undertaken to identify the sets of configuration parameters having a major impact on the handover process for the IEEE 802.16e mobile station. Simulation results could then be used to construct a database for guiding some cross-layer optimization algorithms deciding...
Non-Binary Low Density Parity Check (NB-LDPC) codes are expected to reduce the performance gap between binary LDPC and Turbo Codes for both short and medium length codewords, retaining in both cases the best of each. This paper presents the performance evaluation of NB-LDPC when compared to state-of-art channel coding techniques, namely Convolutional Turbo Codes (CTC) and Quasi-Cyclic LDPC. The performance...
In this paper, gains of the codebook based CL-MIMO for down link WiMax system has been studied using system level simulations. The system level simulation is based on the IEEE 802.16 m evaluation methodology. The 2 times 2 and 4 times 2 antenna configurations, and 3 bits and 6 bits preferred matrix index (PMI) feedback codebooks are considered. Both the sub-band and wide band PMI feedback are studied...
In this paper, we consider the service of voice over internet protocol (VoIP) traffic with the service of non-real time traffic in the mobile WiMAX system. VoIP traffic is delay-sensitive and requires transmission at an almost constant rate. As a consequence, it may require a large amount of resource when users are in poor channel condition, leading to resource outage problem. To alleviate this problem,...
Next generation mobile technologies must provide the throughput and QoS (quality of service) required for dasiatriple playpsila voice, data and media services. Novel applications are required that fully exploit the capabilities of new technology in a spectrally efficient and cost-effective manner. This paper exploits measured and simulated data to determine the range and throughput of mobile WiMAX...
In this paper, an interference-aware analytical model of IEEE 802.16j systems operating in transparent mode is described. The model can be used to determine the throughput gain that can be achieved by 802.16J relay- based systems under a max-min fairness constraint in which the difference between the data rate delivered to all subscribers is minimized. Two variants of the model are considered - one...
We investigate in this paper the impact of mobility on the capacity of an OFDMA-based mobile WiMAX network in the presence of two types of flows: streaming and elastic, under a dynamic configuration where users come to the system following a Poisson process and leave it after a finite duration. This duration is independent on the amount of resources for streaming flow, such as voice, and proportional...
In this paper, we investigate the benefits of two-hop opportunistic relay in time division duplex (TDD) OFDMA cellular network configurations. The paper starts with a short analytical model for the two-hop opportunistic relay. The model expresses the probability of finding a suitable relay node in the presence of lognormal fading and it allows the computation of the expected number of out-of-coverage...
In the next-generation WiMAX system, cooperative communication is being considered as an advanced technique to increase the throughput and improve the signal quality. In a cooperative scenario, multiple stations can jointly emulate the antenna elements of a multi-input multi-output (MIMO) system in a distributed fashion. Unlike conventional space-time coding (STC) mechanisms used by a IEEE 802.16e...
WiMAX systems are being deployed in novel frequency bands often presenting challenges in the manner of reflections, shadowing, etc. Experts can meet many of these challenges when they choose the initial RF settings in a system, such as antenna orientations, downtilts, and transmit power. Once these settings have been chosen, it is a labor intensive process to improve them. However, significant gains...
WiMAX is receiving growing attention as a reliable contender for broadband network applications. Therefore, it is important to develop measures and benchmarks for the performance of this relatively new technology. These benchmarks are intended for service providers in order to be able to plan their networks properly to ensure robust and continuous service to their networks' end users. In this paper,...
A simulation study of the performance of transparent mode relay-based 802.16j systems is described. The study focuses on the gain in throughput that is possible in omnidirectional relay systems and increases in signalling requirements that arise due to the multihop network architecture. The study finds that the introduction of transparent mode relays cannot deliver improved throughput for a substantial...
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