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Copyright (c) 2012 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Copyright and Reprint Permission: Abstracting is permitted with credit to the source. Libraries are permitted to photocopy beyond the limit of US copyright law for private use of patrons, those articles in this volume that carry a code at the bottom of the first page, provided that the per-copy fee...
In this paper, we propose a solution to the carrier frequency offset (CFO) estimation based on data dependent superimposed training scheme for Orthogonal Frequency Division Multiplexing (OFDM) systems. The proposed CFO estimation can improve the bandwidth efficiency compared with traditional pilot assistant scheme because it consumes no extra bandwidth for the training sequence is superimposed to...
The novelty of the peer-to-peer (P2P) paradigm relies on two main concepts: cooperation among users and resource sharing. There are many applications based on peer-to-peer paradigm, but the most popular one is the file sharing. We can classify the file sharing application into centralized systems, (having a central server), and decentralized systems. Another classification would be structured and...
We experimentally demonstrate the feasibility of the bandwidth tuning of a liquid-crystal based bandpass Lyot filter. This bandwidth tuning is achieved by applying a voltage to vary the birefringence of the liquid-crystal cells whose optical path difference takes predefined discrete values. We show that for a 2-stage liquid-crystal Lyot filter and at λi = 1.543 µm, the measured 3-dB bandwidth varies...
In this paper, a spectrum sensing approach for multiple-antenna cognitive radio networks will be proposed. Specifically, we will apply dimension estimation based spectrum sensing technique using minimum description length (MDL) criteria to sense the presence of primary users signals. Therefore, we consider a cognitive radio network with cognitive user equipped with M received antennas and K (M >...
Corner reflector antennas are widely used in various applications where high directivity is required for point-to-point communication systems. Such antennas, in addition to their high directivity, are very practical due to their simple design which makes them competitive in the market from both financial and electrical aspects. In spite of this fact, reflector antennas suffer from sidelobe radiation...
We examine a radio transmission system based on spectrum pooling, whereby the spectrum is divided into subchannels, and some users are allowed privileged access to the most reliable unused subchannels. The performance of this system is evaluated by assuming that a powerful error-control code is used, and hence by computing the information outage probability. It is shown that choosing the best channel...
In this paper, we propose an algorithm to solve the joint frequency resource and transmission power allocation problem for heterogeneous network (HetNet) of LTE-Advanced (LTE-A) systems, which consiste of several types of base station nodes, such as macrocell, picocell (hotzone), femtocell and relay. The optimization problem is formulated to minimize the sum downlink interference power level of all...
In this paper, we consider the fast and slow multipath fading scenarios in which the coherence time of the channel between primary transmitter and secondary receiver is compared to the sensing time. We formulate the detection problem under fast fading, then we show that there are situations in which the detection performance under the fast fading scheme outperforms that of the non-fading case (AWGN)...
Power control is a crucial concern in cognitive radio networks where secondary users compete in an opportunistic way to access idle spectrum of primary users. However, most existing studies in this space have only looked at the interactions between secondary users, without considering the impact of primary user behaviors. In this study a novel realistic primary-secondary game-theoretic scheme with...
An accurate channel estimation is crucial for the novel time domain synchronous orthogonal frequency-division multiplexing (TDS-OFDM) scheme in which pseudo noise (PN) sequences serve as both guard intervals (GI) for OFDM data symbols and training sequences for synchronization/channel estimation. This paper studies the channel estimation method based on the cross-correlation of PN sequences. A theoretical...
In this paper, we consider one secondary user sensing the radio spectrum, and find its optimal sensing parameters to maximize its throughput in a periodic sensing framework, while keeping its interference to primary network below a certain level. To this end, we propose a new interference measure which takes into account not only the probability of detection, but also the secondary user transmission...
This paper studies the resource allocation problem in orthogonal frequency division multiple access (OFDMA) cooperative relaying cellular systems. Most existing work on resource allocation does not fully consider all the influential factors for such systems. In the paper, we formulate the optimization problem for resource allocation, including relay selection, subcarrier assignment, and power allocation...
A symbol-level iterative decoding scheme of non-binary LDPC coded orthogonal modulation with non-coherent demodulation is presented. Compared to the conventionally used bit interleaved coded modulation with iterative decoding (BICM-ID), the proposed scheme directly combine LDPC codes over GF(q) (q>2) with M-ary orthogonal modulation together. The soft input and soft output demodulation with non-coherent...
In this paper we investigate the cooperative beamforming in cognitive radio network (CRN) composed of a primary network (PN) and a secondary network (SN). In the SN, the transmitter has to communicate with the receiver with the help of the hybrid relays which use cooperative beamforming to retransmit data. The relays will select amplify-and-forward (AF) or decode-and-forward (DF) according to the...
One may monitor the heart normal activity by analyzing the electrocardiogram. We propose in this paper to combine the principle of kernel machines, that maps data into a high dimensional feature space, with the autoregressive (AR) technique defined using the Yule-Walker equations, which predicts future samples using a combination of some previous samples. A pre-image technique is applied in order...
In this work, we address the problem of energy-aware multicasting in OFDMA wireless networks. We investigate the optimal allocation of resources with bit rate adaptation to multicast a common content to a set of requesting mobile terminals. In the case of multicasting, the bit rate is limited by the worst channel condition among the receiving mobile terminals on the same subcarrier. In this work,...
This paper presents an efficient decoding scheme for asynchronous physical network coding (PNC) network. The proposed scheme incorporates linear orthogonal projection method into the asynchronous PNC network to eliminate the impact of inter-symbol interference caused by imperfect synchronisation. In terms of the number of floating-point operations to decode per collided information packet at relay,...
802.11 Wireless Local Area Networks (WLANs) and Bluetooth are likely to be used within the same area. The two technologies operate in the 2.4 GHz band. This will result in mutual interference. The new emerging 802.11n Multi Input Multi Output (MIMO) devices implement different Physical and Medium Access Control (MAC) layers compared to legacy 802.11b/g devices. Through empirical experiments, this...
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