In two-way relay channel (TWRC), terminal nodes exchange information assisted by a relay node. To exchange 1bit information over TWRC, the traditional save-and-forward scheme takes 4 time slots. The traditional networ...
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ISBN:
(纸本)9781509039449
In two-way relay channel (TWRC), terminal nodes exchange information assisted by a relay node. To exchange 1bit information over TWRC, the traditional save-and-forward scheme takes 4 time slots. The traditional networkcoding scheme can reduce the number of time slots to 3 since its relay node can mix the information from tow terminal nodes and then broadcast them in 1 time slot. Further, the physical networkcoding (PNC) and analog network coding (ANC) schemes, which allow terminal nodes send the signal simultaneously, only need 2 time slots to complete the information exchange. In this paper, by combining physical networkcoding and full-duplex (FD) techniques, the proposed scheme full-duplex physical networkcoding (FD-PNC) and full-duplex analog network coding (FD-ANC) can nearly reduce the required time slots to 1. Therein, full-duplex technology can make the nodes send and receive the signal at the same time and in the same frequency band by eliminating the self interference signal. Considering the channel error, we analyze their achievable throughput under the symmetric channel. We believe that taking full-duplex technology into networkcoding research may open many possibilities for future work.
Based on the theory of physical layer security (PLS), this paper demonstrates that analog network coding (ANC) has ability to improve the PLS performance of the two-way relay channel against different kinds of eavesdr...
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ISBN:
(纸本)9781538608432
Based on the theory of physical layer security (PLS), this paper demonstrates that analog network coding (ANC) has ability to improve the PLS performance of the two-way relay channel against different kinds of eavesdroppers. In this paper, we define the security and unsecurity region and derive the system security capacity with ANC and traditional transmission schemes. In particular, we consider external and internal eavesdroppers respectively. Besides, we investigate the factors influencing the ANC system PLS performance. The simulation results show that ANC can greatly improve the system PLS performance against an external eavesdropper, and ensure that an internal eavesdropper cannot decode any confidential information. Furthermore, the ANC system PLS performance can be slightly improved by increasing signal source's transmission power level and eavesdropping channel's noise level.
This paper studies the outage performance of a two-way relay transmission, where two user terminals exchange information through a shared relay that exploits analog network coding to deal with the multi-access signals...
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This paper studies the outage performance of a two-way relay transmission, where two user terminals exchange information through a shared relay that exploits analog network coding to deal with the multi-access signals. Starting from some definitions, an exact outage probability of the conventional threenode scenario is derived over frequency-nonselective Rayleigh fading channels. To gain more insight, an approximate expression is also formulated. Following this analysis, opportunistic relaying is considered for multi-relay networks to make a good use of the available diversity degrees of the channel. Then, three significant relay selection strategies, I.e., the max-min, the maxhms and the min-scp policies, are studied and analyzed in terms of outage probability. Simulation experiments are performed and performance comparisons are conducted. The results show that the proposed policies are *** and appropriate methods to implement relay selection and can achieve significant performance gains in terms of outage probability across the whole range of signal-to-noise ratio (SNR) as well as the sources?target rates, which validates the studies in this paper.
We consider a parallel two-way relaying orthogonal frequency division multiple access (PTWR-OFDMA) scheme based on analog network coding in which mobile terminals (MTs) are divided into near-nodes (NNs) and far-nodes ...
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We consider a parallel two-way relaying orthogonal frequency division multiple access (PTWR-OFDMA) scheme based on analog network coding in which mobile terminals (MTs) are divided into near-nodes (NNs) and far-nodes (FNs). An NN communicates with the base station (BS) directly while an FN communicates indirectly via the assistance of NNs. We study the design and analysis issues for PTWR-OFDMA. The proposed scheme has some noticeable advantages. First, the throughput of PTWR-OFDMA increases like, In K, much higher than that of In In K in conventional OFDMA (K is the number of MTs). Second, PTWR-OFDMA can provide much better fairness than conventional OFDMA. Third, the power overhead per NN reduces quickly when K increases if there is a peak rate limitation, implying that there is no strong incentive for some users to avoid providing relaying.
In two-way relay channel(TWRC), terminal nodes exchange information assisted by a relay node. To exchange 1 bit information over TWRC, the traditional save-andforward scheme takes 4 time slots. The traditional network...
详细信息
In two-way relay channel(TWRC), terminal nodes exchange information assisted by a relay node. To exchange 1 bit information over TWRC, the traditional save-andforward scheme takes 4 time slots. The traditional networkcoding scheme can reduce the number of time slots to 3 since its relay node can mix the information from tow terminal nodes and then broadcast them in 1 time slot. Further, the physical networkcoding(PNC) and analog network coding(ANC) schemes, which allow terminal nodes send the signal simultaneously, only need 2 time slots to complete the information exchange. In this paper, by combining physical networkcoding and full-duplex(FD) techniques, the proposed scheme full-duplex physical networkcoding(FD-PNC) and full-duplex analog network coding(FD-ANC) can nearly reduce the required time slots to 1. Therein, full-duplex technology can make the nodes send and receive the signal at the same time and in the same frequency band by eliminating the self interference signal. Considering the channel error, we analyze their achievable throughput under the symmetric channel. We believe th at t aking full-duple x technology into networkcoding research may open many possibilities for future work.
We consider an asynchronous two-way relay network in which a few distributed relays assist in the communication between two single-antenna terminals through analog network coding. The asynchronous transmission between...
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We consider an asynchronous two-way relay network in which a few distributed relays assist in the communication between two single-antenna terminals through analog network coding. The asynchronous transmission between relays and terminals causes symbol misalignments and results in diversity loss in space-time codes (STCs). We propose a family of zero-padded time-reversal STC that can achieve full diversity with low-complexity maximum likelihood (ML) decoding, given a bound for the path delay difference. With ML decoding, the proposed code is decomposed into several independent parts, which greatly facilitate the decoding process. For two-relay scenarios, three code designs based on Alamouti code, quasi-orthogonal spacetime block code, and multigroup decodable STC are provided for each relay with one, two, and four antennas, respectively. For three-relay scenarios, one code design based on quasi-orthogonal space-time block code is provided for each relay with one antenna. Proof of full diversity is established, and the decoding complexity order is analyzed for all four designs. Simulations confirm the full diversity gain of all designs. The bit-error-rate performance in asynchronous scenarios is almost similar to that in synchronous scenarios.
In this correspondence, we propose an analog network coding scheme with differential modulation (ANC-DM) using amplify-and-forward protocol for bidirectional relay networks when neither the source nodes nor the relay ...
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In this correspondence, we propose an analog network coding scheme with differential modulation (ANC-DM) using amplify-and-forward protocol for bidirectional relay networks when neither the source nodes nor the relay knows the channel state information (CSI). The performance of the proposed ANC-DM scheme is analyzed and a simple asymptotic bit error rate (BER) expression is derived. The analytical results are verified through simulations. It is shown that the BER performance of the proposed differential scheme is about 3 dB away from that of the coherent detection scheme. To improve the system performance, the optimum power allocation between the sources and the relay is determined based on the simplified BER. Simulation results indicate that the proposed differential scheme with optimum power allocation yields 1-2 dB performance improvement over an equal power allocation scheme.
In this letter, we present the performance of broadband bi-directional transmission with analog network coding (ANC) in a frequency-selective fading channel. To cope with the channel frequency-selectivity we introduce...
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In this letter, we present the performance of broadband bi-directional transmission with analog network coding (ANC) in a frequency-selective fading channel. To cope with the channel frequency-selectivity we introduce the use of frequency domain equalization (FDE) with broadband ANC based on orthogonal frequency division multiplexing (OFDM) and single carrier (SC) radio access. We evaluate, by theory and computer simulation, the achievable bit error rate (BER) and ergodic capacity of bi-directional ANC scheme based on OFDM and SC-FDE radio access in a frequency-selective fading channel. Our results show that SC-FDE achieves a better BER performance, but on the other hand, a lower ergodic capacity in comparison with OFDM in a frequency-selective fading channel. Through both analysis and computer simulation, our findings show that a drawback of ANC scheme is its lack of diversity combining at the destination, which causes a slightly lower ergodic capacity in comparison with cooperative relaying irrespective of radio access scheme.
The concept of analog network coding (ANC) considers the concurrent transmission of signals over the wireless medium so that they intentionally interfere. Higher network throughput can be achieved with ANC when an int...
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The concept of analog network coding (ANC) considers the concurrent transmission of signals over the wireless medium so that they intentionally interfere. Higher network throughput can be achieved with ANC when an intended transmission that a receiver desires to receive is made to interfere with a concurrent transmission of a signal known a priori at the receiver. In this paper, we present a cooperative protocol that exploits ANC. We consider a system with cooperative relaying of overlapped transmissions from two independent users. More specifically, we explore the case that network nodes may allow the transmitted signals to interfere both at the final destination node, and also at an intermediate node that acts subsequently as a relay. The relay employs a cooperative and multicast amplify-and-forward protocol so that the two destinations can use the interfered signals in order to recover the desired packet. We analyze this protocol in terms of the achieved rate and present an algorithm to recover signals from the overlapped transmissions. We study the impact of overlapping in signal transmissions on the throughput of the system. We show that even with considerable overlapping, the throughput under the proposed protocol is better in comparison to an orthogonal amplify-and-forward protocol.
Time asynchronism is a practical issue need to be addressed for a general distributed two-way relay network, where two terminal nodes exchange information through multiple spatial-separated relay nodes. In this letter...
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Time asynchronism is a practical issue need to be addressed for a general distributed two-way relay network, where two terminal nodes exchange information through multiple spatial-separated relay nodes. In this letter, we propose an analog network coding (ANC) scheme for a time asynchronous two-way relay network. In the proposed scheme, each relay node linearly transforms the received mixed asynchronous signals in the first time-slot by a Toeplitz matrix, and then broadcasts them back to the terminals in the second time-slot. A sufficient condition is derived for the proposed ANC to achieve full cooperative diversity using only linear receivers at the terminal nodes, such as zero-forcing (ZF), or minimum mean square error (MMSE) receivers, with any delay profiles of the timing errors. The decoding of the proposed ANC scheme is computationally efficient and the symbol rate can approach 1, when the coding block length is sufficiently large compared to the number of relay nodes.. and the timing errors.
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