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This paper proposes an adaptive multi-user Multiple Input Multiple Output (MIMO)-Space Division Multiplexing Access (SDMA) technique for uplink access in broadband wireless cognitive networks with multiple primary users (PUs) and secondary users (SUs) sharing the same spectrum. The proposed algorithm uses gradient search of the channel capacity to seek, iteratively, the optimal transmit weight vectors...
Scheduling in a wireless ad hoc network is necessary for sharing of the wireless channel by different nodes to communicate successfully i.e. while meeting the required SINR threshold. Contrary to the infra-structure based wireless networks, the wireless ad hoc network require a scheduling algorithm that should be easily implementable with as little as possible coordination between different nodes...
Wireless full-duplexing enables multi-hop wireless networks to increase network performance, such as the end-to-end throughput. However, the combination of wireless full-duplexing and multi-hop communication produces a secondary transmission collision problem due to the increase of transmission opportunities. This paper proposes directional asynchronous full-duplex medium access control (DAFD-MAC)...
Multi-antenna transmission, or MIMO, is a major enabling technique for broadband cellular networks. The current implementation, however, is mainly for the point-to-point link, and its potential for Space-Division Multiple Access (SDMA) has not been fully exploited. In this paper, we will analytically evaluate the performance of SDMA in multicell networks based on a spatial random network model, where...
In this paper, we propose a novel approach for addressing both inter-cell interference and handover failure issues in dense WCDMA small cell deployments. This is achieved through an innovative scrambling allocation approach and an efficient spreading code allocation scheme that allow appropriate spatial reuse of resources. The proposed enhancements can be implemented in a centralised or distributed...
The operation of wireless cellular networks can be efficiently supported by secondary small cells that are on-demand deployed in traffic hotspots within the coverage area of primary macro cells. Assuming shared communication channels and the uplink communication mode, this study defines deployment guidelines and self-configuration algorithms that enable the coexistence of both the primary and the...
The capacity of WCDMA cell is impacted by interference. Power control reduce fading channels and co-channel interference. WCDMA system require quick and exactly power control. Fuzzy Genetic Algorithm (FGA) deliver the good response to the dynamic and random situations. This paper show application of FGA power control on WCDMA. FGA power control able to increase system capacity by 13.25% and can reduce...
Wireless sensor networks can enhance efficiency in a wide range of settings, from health care to the electric grid. Identifying high-capacity architectures for wireless sensor networks is critical to supporting many of the applications that are envisioned to modernize these sectors. In this paper, we propose a multi-hop architecture with in-band relaying to improve the capacity of cellular sensor...
Data acquisition systems play an important role in several industries. Because highly scalable ad-hoc networks with multi-hop transmissions can be easily constructed at low cost, such networks are considered suitable for data acquisition systems. However, a lack of centralized control makes it difficult to respond to congestion when system capacity is exceeded. Therefore, the estimation of system...
At the present time, an alternative multiple access schemebaptizedinterleave-division multiple access (IDMA) has enticed greatly devotion, in which interleavers are recycled as the only means for user parting. It has been displayed that the IDMAcan accomplish near single user presentation in multiuse surroundings with very truncated receiver complexity. In this broadsheet We equate the presentation...
In recent years, the use of multi-channel MAC protocols in the Wireless Sensor Networks has attracted the attention of many researchers. In this paper, we analyze the different techniques that are used in multi-channel MAC protocols proposed for WSNs. These protocols often use either a centralized or a distributed manner to select and allocate channels. We present HMC-MAC, a Hybrid Multi-Channel MAC...
CSMA (Carrier Sense Multiple Access), which resolves contentions over wireless networks in a fully distributed fashion, has recently gained a lot of attentions since it has been proved that appropriate control of CSMA parameters guarantees optimality in terms of system-wide utility. Most algorithms rely on the popular MCMC (Markov Chain Monte Carlo) technique, which enables one to find optimal CSMA...
In this paper, presents interference suppression using a Space Time Block Coding-Subband Adaptive Array (STBC-SBAA) for uplink W-CDMA system over frequency selective fading channel is presented. The proposed scheme utilizes W-CDMA system with STBC and a receive array antenna with SBAA processing at the receiver. The received signal is converted into the frequency domain before de spreading and adaptive...
For realizing convincing daily shopping, collecting useful market information is very important. Generally, useful market information for shopper relies heavily on time and place in addition to the person's interest. Then, we have considered a new SNS sharing useful market information among shoppers by using smart phone. In this paper, we report an overview of proposed SNS and propose its new communication...
While underwater acoustic sensor networks (UWSN) are still considered to be in their development phase, professional users are starting to understand their future potential. For example, large areas encircling offshore oil installations need to be environmentally supervised. UWSNs consisting of a large number of sensor nodes can present a viable solution to this challenge. One way to build such networks...
An important topic in performance evaluation of wireless networks is the modeling of inter-cell interference, to predict the distribution of the Signal to Interference plus Noise Ratio (SINR) in the network. The classical hexagonal model is generally intractable and requires extensive numerical calculations. Two approaches have been shown to produce tractable, closed-form formulas: Poisson networks...
Interference between macro and femtocells is an important issue for the development of WCDMA femtocell networks. More specifically, the uplink signal of a macro User Equipment may generate an unacceptable level of interference at the femto Base Station. To avoid this situation, interference mitigation techniques could be implemented. All the proposed techniques require the knowledge of the uplink...
Hidden node collision is a significant problem in CSMA/CA (Carrier-Sense Multiple Access with Collision Avoidance)-based multihop networks such as wireless sensor networks. The RTS/CTS (Request to Send/Clear to Send)-based handshaking mechanism is not effective to solve this problem in multihop networks. Also, to reduce power-consumption, such a handshaking mechanism is not used in CSMA/CA networks...
Inter-user interference degrades the reliability of data delivery in Wireless Body Sensor Networks (WBSNs) in dense deployments when multiple users wearing WBSNs are in close proximity to one another. The impact of such interference in realistic WBSN systems is significant but has not been well explored. To this end, we investigate and analyze the impact of inter-user interference in practical WBSN...
In a typical cognitive radio network (CRN), secondary users can only access the channel when they do not harmfully interfere with the primary users. Therefore, an accurate estimation or prediction of interference from secondary users to primary users is essential. In this paper, we tackle the problem of interference estimation in a channel in presence of one PU and multiple SUs. We solve this problem...
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