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Based on considering the CODEC frame duration, this paper proposes a superior uplink scheduling algorithm that can efficiently support multiple DTX VoIP CODECs over M-WiMAX, and be able to facilitate the uplink resource wastes during silence period and optimize the system VoIP capacity. The BS uplink resource allocation procedure is planned and adapted according to the reserved bit in the Bandwidth...
This paper proposes an efficient uplink scheduling algorithm that can perfectly support various VoIP CODECs with VAD/DTX/CNG in M-WiMAX considering the variants of silence duration between different voice users, solving the problems of uplink resources wastes and overwhelmingly large overhead that caused during silence period. In our proposed algorithm, efficient schemes is proposed to implement the...
In this paper, an innovative scheduling scheme is proposed for interference-limited wireless multi-hop networks with non-deterministic fading channels. The scheduling problem is considered as a network utility maximization(NUM) problem subject to link rate constraints. With jointly considering link scheduling and the statistical variations of both signal and interference power, the convex sets for...
This paper proposes a flexible uplink scheduling algorithm that can perfectly support Variable Multi-Rate Wide-Band (VMR-WB) VoIP services with multi-mode codec, solving the problems of uplink resources wastes, additional access delay and overwhelmingly large overhead. In our proposed algorithm, the BS adapts uplink resources assignment according to the reserved bit in the generic MAC header of IEEE802...
IEEE 802.16e standard specifies a system for combined fixed and mobile broadband wireless access. The voice-over-Internet protocol (VoIP) is an important application in IEEE 802.16e system. The algorithm proposed allocates the extra-bandwidth according to the flow's priority, the lagging flow is compensated according to the service it has lost, and the leading flow relinquish bandwidth proportional...
In this paper, an innovative scheduling is designed for multi-hop multicast in wireless mesh networks, with utilization of concurrent transmission strategy. Since the performance of a multicast mechanism is constrained in a wireless setting due to the interference among local wireless transmissions, we analyze the interference relationships firstly among the transmissions by introducing a graph transformation...
This paper deals with the minimum mean square error estimation (MMSEE) of spatial channel model (SCM) in the Third Generation Partnership Project (3GPP) based on orthogonal frequency division multiplexing (OFDM) system. In particular, we focus on MMSEE on the basis of maximum likelihood estimation (MLE). Since statistical information is the critical element of MMSEE, we derive the generation of coefficients...
With rapid development of communication technology, the signal integrity is impacting the system performance much more than before. So either in the IC design or in the system design, it is very important to investigate negative timing analysis and its mathematical modeling in the high speed integrated circuit. In the paper, we introduce the origin of the negative timing script in the deep sub-micrometer...
This paper proposes a novel iterative channel estimator for orthogonal wavelet packet modulation (OWPM) systems over frequency-selective fading channels. The channel estimation algorithm herein designed introduces linear interpolation to compensate the original value offered by expectation-maximization (EM) algorithm for iterative step. With the utilization of the coherence among both subcarriers...
Wireless mesh networks have promised to provide high-speed access for residential or mobile customers. And concurrent transmission is an effective way to enhance system throughput in wireless mesh networks. The objective of this paper is to provide an effective concurrent transmission method to enlarge throughput with specific QoS fairness guarantee in wireless mesh networks. Firstly, link relationship...
A new discrete array signal with good periodic correlation property is discussed, which is ZCZ array pairs. The invariant transformation properties of it were presented. Based on perfect array pair and orthogonal matrix, ZCZ array pairs set with certain volume, family size and zero correlation zone can be synthesized through row or column interleaved technique. Except the binary case, this technique...
This paper deals with the estimation of the channel impulse response (CTR) of spatial channel model (SCM) in the third generation partnership project (3GPP) based on orthogonal frequency division multiplexing (OFDM) system. Maximum likelihood estimation (MLE) contains intrinsic noise, and Bayesian minimum mean square error estimation (MMSEE) is expected to have better performance as it exploits prior...
Orthogonal wavelet packet modulation (OWPM) is a potential technique for achieving high bit rates required wireless access. Effective channel estimation can supply channel state information (CSI) at the receiver, the knowledge of which OWPM system performance relies on. The objective of this paper is to introduce an innovative channel estimation method with unequal interval pilots for OWPM system...
Wavelet packet modulation (WPM) is a potential technique to support high bit rates required wireless multimedia service. Effective channel estimation can improve WPM system performance significantly through channel state information (CSI) acquisition. However the conventional least squares channel estimation is not always appropriate especially in the presence of non-Gaussian channel. In this paper,...
Due to discontinuity of traffic, traffic distribution strategy in each intermediate node and each flow's state before transmission should be considered in non-full load wireless mesh networks when scheduling. In this paper, an activeness-labelled concurrent transmission method with unselfish traffic distribution is designed to enlarge throughput in non-full load wireless mesh networks. Firstly, the...
The voice-over-Internet protocol (VoIP) has attracted a great deal of attention in the field of wireless mobile networks. In this paper, we propose an improved ertPS scheduling algorithm for VoIP services in IEEE Std 802.16e system. It can solve both the problems waste of uplink resources caused by the UGS algorithm as well as MAC overhead and access delay caused by the rtPS algorithm, it also identify...
This paper seek to devise a new scalable and efficient solution to the problem of determining the throughput range using concurrent transmission in wireless mesh networks. After consideration of the conditions for the concurrent transmission scheduling, an easy and efficient algorithm in greedy mode is developed for scenario construction based on the analysis of the interference relationship. Simulation...
Taking the traffic priority of real-time or non-real-time services into consideration, this paper proposes two scheduling algorithms for multimedia services based on the definitions of frame and subchannel in IEEE802.16e. The simulation results show that the proposed algorithms provide better performances of efficiency and fairness than conventional algorithm.
A new construction method of ZCZ arrays set based on interleaved technique is presented. Given perfect periodic autocorrelation array and orthogonal matrix, arrays set with certain zero correlation zone can be constructed through interleaved method. The presented technique has good application foreground in many kinds of array signal design.
WiMax mesh networks based on IEEE 802.16 standard have promised to deliver high data rates over large areas and to be deployed easily. Optimum routing and scheduling of flows can do favor for capacity enlargement. The objective of this paper is to provide a routing-construction method with larger scale applicability and a concurrent transmission scheduling strategy to improve the performance during...
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