Accommodating the coverage and capacity requirements of wireless cellular communication systems evolved contemporary cellular architectures to comprise two tiers: A macro-cell overlay coverage tier encompassing a smal...
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ISBN:
(纸本)9781538617342
Accommodating the coverage and capacity requirements of wireless cellular communication systems evolved contemporary cellular architectures to comprise two tiers: A macro-cell overlay coverage tier encompassing a small-cell tier offloading user traffic in high traffic demand areas. While two-tier cellular architectures can effectively meet coverage and capacity requirements when operating on independent frequency bands, radio spectrum scarcity entails sharing spectrum by both tiers which substantially complicates interference management for such architectures. In order to address uplink interference in two-tier cellular architectures, this paper considers the joint application of dual space-frequency block codes (SFBC) and signal alignment (SA) enabled physical network coding (PNC). When compared to designs adopting interference alignment (IA) or PNC, the proposed joint dual-SFBC with SA-PNC design substantially reduces interference and enables connecting a larger number of users. Numerical results also verify that the proposed method outperforms the SA-PNC static method without any information exchange requirement between the two tiers while achieving close to optimal performance for macrocells.
In this paper, we consider the application of signal alignment (SA) enabled physical network coding (PNC) for the uplink of heterogeneous networks. The joint design of SA and PNC has the potential of fully exploiting ...
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ISBN:
(纸本)9781509059355
In this paper, we consider the application of signal alignment (SA) enabled physical network coding (PNC) for the uplink of heterogeneous networks. The joint design of SA and PNC has the potential of fully exploiting the precoding space and can achieve better spatial diversity of a multi-input multi-output (MIMO) networks that provides higher system degrees of freedom (DoF), than the case where only PNC or interference alignment (IA) is employed individually. In this work, we consider a scenario with a set of small-cells coexist under the same spectrum with the macro-cell. For this scenario, we design new joint SA and PNC based schemes under different levels of inter-tier coordination. We compare the proposed joint SA-PNC schemes with the IA based techniques, recently designed for uplink heterogeneous systems. Simulation results show that the proposed SA-PNC is quite efficient to remove the intertier/system interference while allowing to increase the overall data rate, by serving more users, as compared with the IA based methods.
Cooperative spectrum sensing is investigated in cognitive radio (CR) networks over Rayleigh fading channels. By utilizing the relay to enhance the reliability of the sensing information reporting, cooperative spectrum...
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Cooperative spectrum sensing is investigated in cognitive radio (CR) networks over Rayleigh fading channels. By utilizing the relay to enhance the reliability of the sensing information reporting, cooperative spectrum sensing algorithm based on the relay is proposed. physical network coding is used for the relay and the method for relay selection is discussed. The simulation results show that cooperative spectrum sensing algorithm based on the relay can achieve better performance. (C) 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of [CEIS 2011]
This paper considers precoding schemes in physicalnetwork coded two-way MIMO relay channels. We propose a lattice reduction aided Tomlinson-Harashima Precoding(THP) scheme at first, and compare it with the existing a...
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ISBN:
(纸本)9780769539409
This paper considers precoding schemes in physicalnetwork coded two-way MIMO relay channels. We propose a lattice reduction aided Tomlinson-Harashima Precoding(THP) scheme at first, and compare it with the existing amplify-and-forward (AF) scheme, zero-forcing (ZF) schemes, traditional decode-and-forward (DF) scheme and networkcoding (NC) scheme. Simulations show that the proposed scheme outperforms the existing schemes. This improvement is because we have combined the advantages of both THP and lattice reduction thus the effective transmitting power is significantly increased.
With the increasingly obvious trend of satellite communication and network integration, especially the emergence of inter satellite links, the interconnection between space nodes has become the development trend and i...
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With the increasingly obvious trend of satellite communication and network integration, especially the emergence of inter satellite links, the interconnection between space nodes has become the development trend and inevitable requirement of future space communication. However, problems, such as long communication distance, large transmission delay and loss, limited network resources and frequent switching of transmission links, limit the ability of spatial information transmission. Firstly, based on the idea of ring planning and design, this paper uses the joint design of beamforming between nodes to design the physical layer networkcoding in the relay to realize the reliable transmission of information. Secondly, according to the diversity of relay signal space resources and network node information exchange, a joint design method of relay compression matrix and node precoding vector is studied, which breaks through the existing configuration constraints. In this scheme, the computational complexity is reduced by compressing and precoding the matrix to ensure reliable decoding while obtaining spatial alignment gain and degrees of freedom. Simulated and real data results demonstrate the superiority and effectiveness of the proposed method.
It is well known that symbol-level regenerative relay protocols suffer the error propagation problem because receiver decodes blindly and overlooks the probability of relay forwarding wrong bits. In a two-way relay ne...
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It is well known that symbol-level regenerative relay protocols suffer the error propagation problem because receiver decodes blindly and overlooks the probability of relay forwarding wrong bits. In a two-way relay networks, the problem still exists in both networkcoding (decode-and-forward) and physical network coding (denoise-and-forward) protocols. For today's widely adopted wide band Orthogonal frequency-division multiplexing (OFDM) systems, error propagation will dramatically restrict the system's end-to-end performance especially when frequency selective fading exists. In this paper, we propose a bit error rate (BER) modified decoding algorithm for these OFDM-based two-way symbol-level regenerative relay strategies. By confining the confidence level of demodulated soft information according to the likelihood of relay having made an error on each bit, this proposed algorithm significantly boosts the end-to-end BER performance of the system. Copyright (C) 2015 John Wiley & Sons, Ltd.
Cooperative spectrum sensing is investigated in cognitive radio (CR) networks over Rayleigh fading channels. By utilizing the relay to enhance the reliability of the sensing information reporting, cooperative spectrum...
详细信息
Cooperative spectrum sensing is investigated in cognitive radio (CR) networks over Rayleigh fading channels. By utilizing the relay to enhance the reliability of the sensing information reporting, cooperative spectrum sensing algorithm based on the relay is proposed. physical network coding is used for the relay and the method for relay selection is discussed. The simulation results show that cooperative spectrum sensing algorithm based on the relay can achieve better performance.
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