Packet Length Optimization for Two Way Relaying
01 Jun 2019-pp 735-740
TL;DR: It is demonstrated, in this paper, that the proposed Optimal Packet Length (OPL) allows to enhance the system throughput.
Abstract: In this paper, a method to optimize packet length for two way relaying systems is suggested. Two source nodes N 1 and N 2 are transmitting data simultaneously to each other through a selected relay. The relay amplifies the sum of N 1 and N 2 signals. N 1 (respectively N 2 ) retrieves its own signal to be able to detect that of node N 2 (respectively N 1 ). In the existing literature, a Fixed Packet Length (FPL) is used and it is demonstrated, in this paper, that the proposed Optimal Packet Length (OPL) allows to enhance the system throughput.
References
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TL;DR: The integral inequality lemma is applied to extend research to more general Nakagami-m fading channel and can be applied to evaluate the average packet error rate of a conventional packet transmission system over a quasi static fading channel.
Abstract: We propose a new analytical approach to evaluate the average packet error rate (PER) of a conventional packet transmission system over a quasi static fading channel, by presenting an integral inequality lemma. The basic idea of the approach is that, given the PER for the AWGN channel as a function of signal-to-noise ratio (SNR), the average PER over Rayleigh fading channel can be generally upper bounded by a quite simple inequality, i.e.,1 - exp(-wo/γ), for both coded and uncoded schemes, where wo, defined by an integral expression, corresponds exactly to the inversion of coding gain; and this bound is tight in the high SNR region or for long packet systems. We further apply the integral inequality to extend our research to more general Nakagami-m fading channel.
137 citations
TL;DR: A new space–time line code (STLC)-based TWR method is proposed to improve the EE and can be readily extended to a TWR system with a large number of antennas, e.g., a massive MIMO system, which is one of the promising candidates for 5G communications.
Abstract: In multiple-input multiple-output (MIMO) systems, per-antenna power constraint (PAPC) has been considered to enhance the power efficiency of the multiple power amplifiers. Under PAPC, however, a conventional space-division multiple access (SDMA)-based two-way relay (TWR) method suffers a significant bit-error-rate (BER) performance degradation due to the seriously down-scaled transmit power to fulfill the PAPC, which results in energy-efficiency (EE) degradation. In this paper, a new space–time line code (STLC)-based TWR method is proposed to improve the EE. The proposed method can utilize maximum power budget with a low peak-to-average power ratio so that can achieve a better BER performance at the cost of higher power consumption, as verified in numerical simulation results. The benefit of the proposed STLC-based TWR method is justified in terms of EE. The STLC-based TWR system achieves higher EE than the conventional SDMA-based TWR when the maximum transmit power is low, such as a small base station with 23-dBm maximum transmit power. Furthermore, compared with the SDMA-based TWR, the proposed STLC-based TWR can reduce computational complexity by order of magnitude two; therefore, it can be readily extended to a TWR system with a large number of antennas, e.g., a massive MIMO system, which is one of the promising candidates for 5G communications.
32 citations
"Packet Length Optimization for Two ..." refers background or methods in this paper
...In all previous studies, a Fixed Packet Length (FPL) is used [1-14] which is not optimal to achieve higher throughput....
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...The corresponding Signal to Noise Ratio (SNR) is the maximum of SNRs over all antennas....
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...When the selected relay maximizes the SNR at node N1, the CDF of SNR is the products of CDF of SNRs of different relays FΓ1(x) = K∏ k=1 FΓk1 (x) (20) where Γk1 is the SNR at node N1 when relay Rk is the active relay....
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...The SNR will be the sum of all SNRs [1-5]....
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...Two way relaying for Multiple Input Multiple Output (MIMO) systems has been considered in [1-5]....
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TL;DR: It is shown that, when a certain time delay is tolerable, the DAAT scheduling scheme is able to realize a rate region arbitrarily close to the achievable rate region of the buffer-aided two-way wireless EH relay network.
Abstract: In this paper, we investigate the buffer-aided two-way wireless energy harvesting (EH) relay network comprising two users and one relay, where two users exchange information with the help of the relay via three phases of EH, multiple-access, and broadcast . By transforming the opportunistic scheduling design problem into an equivalent convex problem, we present the adaptive design for the buffer-aided two-way EH relay network to maximize the long-term achievable rate region. To fulfill the delay sensitive transmission requirements, a delay-aware adaptive transmission (DAAT) scheduling scheme is proposed to guarantee the average end-to-end delivery delay by employing the Lyapunov optimization framework. Our analysis discloses that the average achievable rate region of the two-way wireless EH relay network can be improved when fully considering the potentials by deploying data buffer and energy storage at the relay. There exists an inherent tradeoff among the achievable sum rate, the delivery delay, and the power consumption. It is shown that, when a certain time delay is tolerable, the DAAT scheduling scheme is able to realize a rate region arbitrarily close to the achievable rate region of the buffer-aided two-way wireless EH relay network.
28 citations
"Packet Length Optimization for Two ..." refers background or methods in this paper
...In all previous studies, a Fixed Packet Length (FPL) is used [1-14] which is not optimal to achieve higher throughput....
[...]
...Relays with EH capabilities has been studied in [6-10]....
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...TWR with Energy Harvesting (EH) systems use the Radio Frequency (RF) signal to charge the battery of nodes [6-10]....
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TL;DR: An iterative algorithm is proposed to decompose the original SSR maximization problem into four individual subproblems that can be reformulated as three types of convex problems, i.e., the generalized Rayleigh quotient problems, the polynomial time differential convex problem, and the semidefinite programming problem.
Abstract: In this paper, secure wideband beamforming design is investigated for two-way multiple-input multiple-output (MIMO) relaying systems with one eavesdropper. Due to the wideband signals exchanged by two sources via the relay, inter-symbol-interference (ISI) occurs inevitably and makes the beamforming design more challenging than the narrowband beamforming design. To sufficiently combat the ISI, the tapped delay lines are deployed at the relay. Besides, to reduce the computational complexity at the tapped delay lines based relay, the analog beamforming structure is also considered, and thus the MIMO relay beamforming can be distinctly partitioned into a transmit beamforming and a receive beamforming bridged by a single link. Joint optimization of the transmit and receive beamformings at both the relay and two sources is considered to maximize the secrecy sum rate (SSR) of the two-way MIMO relaying systems. Since the joint optimization is nonconvex and intractable, an iterative algorithm is proposed to decompose the original SSR maximization problem into four individual subproblems that can be reformulated as three types of convex problems, i.e., the generalized Rayleigh quotient problems, the polynomial time differential convex problem, and the semidefinite programming problem. A suboptimal solution for the secure transmit and receive beamformings at all nodes can then be obtained iteratively. Finally, numerical experiments are conducted to corroborate the effectiveness of our proposed iterative algorithm in terms of the achievable maximum SSR and ISI suppression.
15 citations
"Packet Length Optimization for Two ..." refers background or methods in this paper
...In all previous studies, a Fixed Packet Length (FPL) is used [1-14] which is not optimal to achieve higher throughput....
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...Secure two way relaying has been also suggested in [14]....
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25 Jun 2018
TL;DR: Numerical results enlighten the importance of considering direct link with MRC in the SWIPT-enabled two-way relay systems.
Abstract: In this paper, we analyze the performance of simultaneous wireless information and power transfer (SWIPT) in two-way relay systems with an active direct link under Nakagami-m fading environment. We consider a three-node based cooperative relaying system consisting of two source nodes and a battery-enabled relay node. Herein, one round of information exchange between source nodes can be accomplished in three time phases. Relay node relies on amplify-and-forward (AF) operation to broadcast the signals, while the destination nodes utilize maximal-ratio combining (MRC) technique to make use of both the direct and relay links. Moreover, the relay node harvests energy from the radio-frequency (RF) signals in the first two phases using power-splitting (PS) approach and then utilizes the harvested energy for information processing and broadcasting the received signals in the third phase. For the considered setup, we proficiently derive accurate expressions for the outage probability (OP), system throughput, and energy efficiency. Numerical results enlighten the importance of considering direct link with MRC in the SWIPT-enabled two-way relay systems.
9 citations
"Packet Length Optimization for Two ..." refers background or methods in this paper
...In all previous studies, a Fixed Packet Length (FPL) is used [1-14] which is not optimal to achieve higher throughput....
[...]
...Relays with EH capabilities has been studied in [6-10]....
[...]
...TWR with Energy Harvesting (EH) systems use the Radio Frequency (RF) signal to charge the battery of nodes [6-10]....
[...]