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Compressive sensing (CS) is a viable source of an innovative 5G system, what's more, it's an effective technology to deal with the data redundancy problem of massive machine-to-machine communication (MMC), since it enables the recovery of sparse and approximately sparse signals with significantly fewer samples than demanded by Nyquist-Shannon sampling theory. Interference in signal will lead a series...
The densification of small cells (SCs) and caching at the edge are two promising approaches to improve the network throughput, reduce end-to-end delay and backhaul cost in future 5G wireless networks. However, current analysis and design only focus on the system state at a certain time, neglecting the temporal-spatial fluctuation of traffic and the content popularity variations, which are often affected...
In wireless cellular system, due to the convergence of user behavior, there usually exists some typical scenarios which exhibit different traffic patterns, e.g. stadium, campus and central business district (CBD). Accurate traffic scenario recognition and analysis will lead to more efficient resource management and better QoS (quality-of-service) provision. In this paper, with the idea of social network...
Understanding the spatial traffic patterns of wireless cellular system could facilitate the performance analysis and system design. In this paper, a novel method based on base stations social network (BSSN) is proposed for the prediction of spatial traffic in wireless cellular system. Firstly a BSSN, which can describe the spatial traffic relationship between base stations (BSs), is established with...
Initial cell search synchronization in the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) system includes the time synchronization, the frequency synchronization of frames and the acquisition of cell identity (Cell ID). How to efficiently compensate initial frequency offset, combat uplink interference and adjust the automatic gain control (AGC) in initial cell search procedure...
In TDD OFDMA systems for IEEE 802.16e, uplink synchronization is mainly accomplished by initial ranging, which includes multi-user ranging code detection, multi-user timing adjusting and power estimation. In this paper, a novel initial ranging scheme is present, using generalized chirp-like(GCL) sequences to overcome the existing ranging method's drawbacks namely high complexity, high probability...
This paper considers the uncertain factors under electricity market, calculates the probabilistic distribution of the Locational Marginal Price (LMP) based on the Point Estimate Method (PEM) 2n+1 scheme. What is more, the correlated loads are considered. The method has higher efficiency than Monte Carlo Simulation (MCS), and the procedure of linearizing the power flow equation in analytical method...
There has been a growing interest in analog network coding, which can improve system throughput and spectrum efficiency significantly in wireless systems. Two-way relay scenario is considered in this paper, where the base station (BS) and the relay are both equipped with multiple antennas, and each of K user equipments (UEs) in the cell has a single antenna. An advanced multi-user scheduling scheme...
A new unequal-error-protected space-time block code (UEP-STBC) is designed in this paper for multimedia transmission systems deployed with multiple antennas. Traditionally, a space-time code is designed to support a single information stream aiming to achieve a point on the fundamental rate versus diversity tradeoff curve, while this proposed class of codes has the capability of transmitting different...
We consider a two-way relay system where two sources exchange information with the assistance of multiple, non-cooperative, relay nodes. Specifically, we propose a capacity upper bound for the two-way relay channel and derive the achievable regions for different relay strategies, such as the amplify-and-forward (AF), the decode-and-forward (DF) and the compress-and-forward (CF). Furthermore, the upper...
Precoding is an efficient approach to obtain high channel capacities and high quality in multiple-input-multiple-output systems and draws much attention in recent researches. In the codebook-based precoding systems, the tradeoff between performance and feedback overhead should be considered. In this paper, a novel version of the Linde-Buzo-Gray (LBG) algorithm is first utilized in the codebook design...
In the next generation wireless systems, it's quite likely that a large number of user terminals are not able to transmit and/or receive over the entire system bandwidth, as much wider system bandwidth, e.g., 100 MHz, is expected to be employed in the future. As a new and challenging problem, user terminal bandwidth limitation is considered in this paper, and multiuser resource allocation for orthogonal...
In this paper, we propose a practical strategy that integrates beamforming with MIMO (Multiple-Input and Multiple-Output) technique to both combat fading and diminish interference. By dividing the antenna array into several groups, termed subarray, virtual MIMO system is composed. In this paper, two kinds of antenna configuration are proposed, and both their array gain and diversity gain are analyzed...
This paper presents the activities in realizing and testing cognitive radio system by means of a software defined radio. The first part of this prototype is the sensing part which scans the TV band (100-700 MHz) to find the vacant spectrum hole. The signal's cyclostationary feature and the chi-square test are used to judge the signal existence. The demo can detect CMMB and DMB-T signal by cyclostationary...
In this paper, the Cramer-Rao lower bound (CRLB) for spatial correlation matrices is derived based on a rigorous model of the doubly selective fading channel for multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. Adopting an orthogonal pilot pattern for multiple transmitting antennas and assuming independent samples along the time, the sample auto-correlation...
In this paper, a novel maximum Doppler spread estimation algorithm is presented for OFDM systems with the comb-type pilot pattern. The least squared estimated channel frequency responses (CFR's) on pilot tones are used to generate the auto-correlation matrices with/without a known lag, from which the time correlation function can be measured. The maximum Doppler spread is acquired by inverting the...
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