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In the distributed cognitive radio networks, users possess the ability to detect spectrum holes to communicate with others which make the traditional routing protocol ineffective. The fundamental challenges here are the interruptions which occur when primary users emerge and how to exchange messages to maintain the route in this situation. To deal with the problem, we propose a novel on-demand routing...
Computer-centered services and broadband wireless connectivity are enabling the delivery of multimedia-based entertainment from the Internet to in-house wireless devices and appliances. In this context, rich-media applications can be supported by different protocols that must share the same channel without affecting each other performances. Instead, with current systems, real-time applications (e...
In MIMO multi-relay systems, close-loop precoding at relay nodes is not necessary if unicast modes are carried out. However, in unicast modes, the inter-stream interference at relay nodes may degrade the system capacity. In this paper, two unicast modes are proposed to reduce the negative impact of the residual interference. The first one suppresses the interference by applying orthogonal precoding...
In this paper, a new beamformer is proposed for coherent signal reception with the assumption that the directions-of-arrival (DOA's) of the uncorrelated interferers are available. Here, the composite vector of the coherent sources is first estimated based on the use of a transformation matrix to eliminate the uncorrelated interferers. Then the optimum beamforming is performed based on the estimated...
Combining polarization filtering with the oblique projection, we address an oblique projection polarization filter (OPPF) which enables the extraction of the desired polarized waves while suppressing the unwanted polarized interference signals, based on estimating the polarized parameters subspaces of desired signals and interferences. The simulation results show that the OPPF is a valid means to...
We consider systems of mobile robots that execute a transportation task and periodically recharge from a docking station. The location of the docking station has a considerable effect on task performance. In nonstationary tasks the optimal dock location may vary over the length of the task. In multiple-robot systems, spatial interference between charging and working robots can make it difficult to...
The general two-user memoryless multiple-access channel with partial or full channel state information among the encoders has no single-letter solution which explicitly characterizes its capacity region. In this paper a binary dirty multiple-access channel with interference known at one/both encoders is considered. Specifically, we derive formulas for the capacity region of the doubly-dirty multiple-access...
Since IEEE802.22 is required to reuse the fallow TV spectrum without causing harmful interference to the incumbents (i.e., the TV receivers), Cognitive Radio (CR) techniques are of great importance to get access to the TV bands opportunistically. Meanwhile, the opportunistic spectrum access (OSA) model provides an approach to allow the compatibility between low-power cognitive devices and the incumbents...
ADBF is one of crucial techniques for phased array radar, which generally contains thousands of element. It usually adopts subarray configuration and can get only digital outputs of subarrays. Direct subarray weighting(DSW) configuration based on linearly constrained minimum-variance(LCMV) is an effective solution for ADBF, while the performance degrades in the presence of array imperfections such...
In this paper, a distributed power control algorithm is proposed to perform adaptive spatial multiplexing for the relay enhanced orthogonal frequency division multiple access (OFDMA) cellular systems. As the optimal spatial multiplexing problem is non-convex, we utilize the distributed iteration method to achieve its near-optimal solution. By determining the restriction on the transmit power for each...
The throughput of a linear cellular uplink with a random number of users, different power control schemes, and cooperative base stations is considered in the large system limit where the number of cells is large for non fading Gaussian channels. The analysis is facilitated by establishing an analogy between the cellular channel per-cell throughput with joint multi-cell processing (MCP), and the rate...
In the progress of standardization of 3GPP Long Term Evolution (LTE), it is of the most importance to ensure the coexistence between LTE system and other systems. This paper is aiming at presenting a clear is deployed co-existed with TD-SCDMA system, which has been deployed in China. Monte Carlo simulation is used to get the statistic results. The two systems are assumed to have similar uplink and...
3GPP LTE specification is stable now in release 8. To meet much higher requirements than release 8, 3GPP has initiated the LTE-A (LTE-Advanced) study item. In LTE-A, CoMP (coordinated multiple point transmission and reception) and CA (carrier aggregation) are two new features. CoMP is used to improve coverage and to increase cell-edge throughput. It is considered as an effective approach for ICIC...
Improving frequency interference is the primary purpose of network planning and optimization in TD_SCDMA. In this paper, a new algorithm to improve frequency interference, named Ant Colony Algorithm (ACA), was put forward to; in addition existent methods were enriched. We described ACA principle, and then a new specific scenario was investigated and introduced into the frequency planning. Afterwards,...
This paper introduces a novel heuristic algorithm for N-user detection in synchronous CDMA multiple access networks. In such systems, the performance of the conventional single-user detection technique (i.e. a rake receiver compounded by a set of matched filters) is clearly bounded by the well-known multiple access interference (MAI). To avoid this limitation, the optimum maximum likelihood (ML) detection...
In this paper we have considered the channel assignment problem in multi-channel multi-radio wireless mesh networks. The problem is to assign channels to links in the network with the original topology preservation, and aim at minimizing the overall network interference which is proved to be NP-hard. We have first illustrated that the conversion from the channel assignment problem to the max k-cut...
2-dimensional (2D) block spread CDMA makes it possible to achieve multiple-access interference (MAI) free uplink transmission with low-complexity single-user detection and therefore is very attractive. In this paper, we propose a code assignment algorithm for 2D block spread CDMA uplink in multi-cell systems. It is shown by the computer simulation that in the frequency-selective fading channel, the...
In this study we docked one compound substances of vanadium in the body, V03 (molecular formula 013V4, partial vanadate tetramer) and ppGalNAcT2, which shows that V03 may inhibit the activity of the enzyme by stopping conformational changes of a key loop of ppGalNAcT2. Besides, through experiments we discovered that at mRNA level, ppGalNAc-T2 changed with the variation of HL-60 cell growth induced...
The capacity of feedback links is typically limited and shared by multiple users. So this paper studies the impacts on multiple input multiple output (MIMO) broadcast channel (BC) when limited feedback capacity is shared among multiple users. Our mathematical analysis proves that in the high signal-to-noise ration (SNR) region, allocating the whole feedback capacity to a single user is the optimal...
In this paper, we will propose a framework for computing detection (Pd) and false alarm (Pfa) probabilities for chip-time differential transmitted-reference (Tc-DTR) receivers over frequency-selective multipath fading channels further impaired by narrow-band interference (NBI). We will show that, when compared to similar non-coherent receiver architectures, Tc-DTR offers an intrinsic robustness to...
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