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In this paper, the problem of rate allocation in IS-856 uplink is investigated, using a control theoretic approach. An adaptive control scheme is used to stabilize the wireless network and achieve interference regulation. The system stability and output performance are studied in the case of non-fully buffered users for a dynamic network, in the framework of switched systems. Simulation results confirm...
In this paper a composite analytical model of DS-CDMA wireless communication system considering multipath Nakagami fading along with Doppler frequency shift, tracking jitter, local oscillator frequency offset and multi-access interference (MAI) for different PN sequences is presented. The analysis presents the development of a novel approach to find the pdf (probability density function) of the signal...
In this paper, we propose a framework for analyzing downlink performance of cellular CDMA network without considering retransmission protocol in MAC layer. More specifically, we develop a simulation testbed for analyzing broadcast performance of WCDMA network in presence of both PHY layer and application layer forward error correction (FEC) codes only. In physical layer, low density parity check (LDPC)...
In cognitive radio (CR) networks, power control is necessary to not only decrease the interference among the secondary users (SUs), but also avoid negative impact to the primary users (PUs). To meet the communications needs between PUs and SUs in cognitive radios and to ensure that the unimpaired operation of the PUs and SUs' communications be not intermitted, a MC-CDMA cognitive radios system and...
This paper evaluates the end-to-end outage probability of a CDMA based static multi-hop wireless sensor network (WSN) in shadowed environment. An interference model for multi-hop is presented considering correlation amongst interferers. Three different information delivery mechanisms are studied using regenerative relays with or without error correction capability. Outage probability for each mechanism...
Femtocells are assuming an increasingly important role in cellular coverage. Femtocells can be configured to be either open access or closed access. Seemingly, the network operator would prefer an open access deployment since this provides an inexpensive way to expand their network capabilities, whereas the femtocell owner would prefer closed access, in order to monopolize their femtocell capacity...
Femtocells are low-power base stations to extend the cellular network coverage and provide high speed data service for indoor environments. To solve the severe interference problem introduced by unattached co-channel users, the interference mitigation technique, uplink attenuation, can be implemented at femtocell receivers. In this paper, we investigate the close-form outage probability function to...
TD-SCDMA is one of the third generation (3G) mobile communication standards, which is coming into the commercial phase. Along with the network deployment, planning and optimization tools are playing an important role to ensure the network performance. Scanner is one of the important tools, contributing to optimize the wireless network performance via drive test, tower site survey, in-building measurement,...
Allocating appropriate channels to the users (UE) is an important challenge in mobile networks. Heuristics Algorithm may be used to solve this problem. In this paper, a new time slot allocation (TSA) algorithm based on genetic algorithm (GA) is proposed after comparing to the dynamic queue TSA algorithm. The new algorithm is simulated and analyzed on the TD-SCDMA Radio Resource Management Simulation...
This paper proposed a more realistic imperfect power control model for Signal-to-interference radio (SIR)-based call admission control algorithms comparing with the previous method in CDMA systems. A new call is accepted by a base station if the measured SIR can be guaranteed based on our proposed model. Similarly, we considering the voice, data multimedia traffic services, etc. The simulation results...
In the CDMA cellular mobile communication system, the order of neighbor cell list (NCL) determines whether the mobile station can make a success handoff to the best neighbor in time. Therefore, the success rate of handoff depends on the suitability of the NCL's management, which directly affects network performance. Traditional NCL algorithm used the method of manual observation and was adjusted by...
Based on a Space-Time Block Coding Multi-Carrier Code Division Multiple Access (STBC MC-CDMA) system, a Asynchronous Distributed Pricing (ADP) Algorithm is studied in this paper, in which the cognitive radio(CR) users announces a price that reflect other users' compensation paid. The power control is implemented by updating pricing and power level. The ADP algorithm is a distributed power control...
For single-carrier systems with frequency domain equalization, decision feedback equalization (DFE) performs better than linear equalization, and has a lower complexity and computational costs than optimum equalizers. The main challenge in DFE is the feedback symbol selection rule. In this paper, we give a theoretical framework for a simple, sparsity based thresholding algorithm. We feedback multiple...
In this paper, a two-tier UMTS network is considered where a large number of randomly deployed Wideband Code Division Multiple Access (WCDMA) femtocells are laid under macrocells where the spectrum is shared. The co-channel interference between the cells may be a potential limiting factor for the system. We study the uplink of this hybrid network, and identify the critical scenarios that give rise...
In this paper, we propose a novel algorithm to remove secondary users (SUs) in a Cognitive Radio (CR) CDMA network to maintain a predefined interference threshold at BS. Specifically, we develop a simulation test bed for analyzing performances of a CR user and a primary user (PU) in a single cell. CR users or SUs are assumed to form pair wise link in an infrastructure less ad hoc network that coexists...
Uplink capacity of multi-cell multi-service multi-carrier TD-SCDMA system employing smart antenna and multi-user detection is investigated by analysis and simulation. Relation between the user numbers and the required signal-to-noise ratios is derived. Neighboring cell interference is studied, and its statistics are obtained under the conditions of different scrambling code allocation schemes. Capacity...
The objective of the present paper is to propose a rapid and accurate method for the evaluation of the quality of service (QoS) perceived by the users in the uplink of wireless cellular networks. In doing so we aim to account for the dynamics induced by the arrivals and the departures of the users. In particular, the QoS is evaluated in terms of the blocking probability for streaming users and the...
Femtocells are low-power base stations which improve signal coverage in indoor environment. In order to deploy femtocells in macro cells, one of the essential issues is to evaluate the interferences towards the mobile users served by the macro cells. In this paper we mainly analyze the system performance of TD-SCDMA cellular radio network for HSDPA data services when operating femtocells. The fixed...
The femtocell is a recommended solution to the indoor coverage and throughput problem. In this paper, we study a scenario with only one femtocell access point, one subscriber and N nonsubscribers in CDMA system. Considering the limitation of the backhaul throughput and all the users' benefits, we design a novel femtocell open access mechanism based on the greedy algorithm. The analysis and simulations...
In this paper, the performance of a Cognitive Radio (CR) CDMA networks is analyzed in uplink. More precisely, we develop a simulation testbed for analyzing performances of a CR user and a primary user (PU) in a single cell. CR users belong to infrastructure less ad hoc network, which coexist with a primary radio network (PRN). CR users or secondary users (SUs) are considered to form pair wise links...
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