Wireless Communications Systems

Session WCS-07

Advanced Wireless Techniques I

Conference
10:30 AM — 12:00 PM CST
Local
Aug 10 Mon, 10:30 PM — 12:00 AM EDT

Blocking- and Delay-aware Flow Control Using Markov Decision Process

Yixuan Wang (Xi'an University of Posts & Telecommunications, China); Changyin Sun (College of Xi'an Post and Communication, China); Fan Jiang (Xian University of Posts and Telecommunications, China); Jing Jiang (Xi'an University of Posts and Telecommunications, China)

0
In the transition period of 5G, LTE/5G dual-connectivity(DC) is a key solution which can not only meet the user's traffic demand, but also can provide offloading flexibility for hot spot data services. To further enhance the dual connectivity performance, the mmWave technique is adopted in low power node. Although be promising, the enhanced framework still face challenges due to the limits in practical deployment, such as delay between the interface of different nodes, and intermittent transmission of blocked mmWave link. In this paper, we address the flow control algorithm of the mmWave enhanced dual connectivity scenario, where a user equipment (UE) downloads a file with split bearer architecture of DC, taking into account the link's blocking state, the delay difference of split data flow transmission, energy consumption and QoS of UE. We model this problem as a finite level discrete-time Markov decision process, and use the dynamic programming algorithm to get the optimal solution. The performance of the proposed flow control algorithm is verified by a large number of simulations. The results indicate that even under the uncertainties of blocking, the transmission can be finished energy efficiently without violation of delay budget. Moreover, as synchronization between the different links of split bearer are kept, packet loss due to reordering window is avoided.

Energy Consumption Minimization using Data Compression in Mobile Edge Computing

Bo Wang, Yaqiong Liu, Guochu Shou and Yihong Hu (Beijing University of Posts and Telecommunications, China)

0
In recent years, many researchers have done a lot of work on mobile edge computing (MEC). However, existing works on energy minimization of MEC systems mainly focus on comparing energy consumption between accomplishing tasks locally and computing tasks on MEC server, failing to explore energy optimal solutions for computing tasks on MEC server. In this paper, we consider a single-user-single-server MEC system, working under latency constraint. In order to reduce the energy consumption of mobile device and meet the latency constraint, we use computation offloading to accomplish large tasks. However, energy consumed by mobile devices (MD) for the transmitting process could be decreased further by compressing data transmitted from MD to mobile-edge server (MEC server). But energy consumed when compressing data on MD increases while the compression rate decreases. Therefore, we develop a solution to figure out the optimal compression rate to minimize the total energy for MD to accomplish one simple task and to meet the latency constraint at the same time. With the optimal compression rate, energy consumption for task-process could be reduced by 38.37% to 60.49% when the latency constraint varies from 0.1s to 0.8s.

Multiuser Offloading Strategy Based on User's Computing Ability in Massive MIMO System

Gong Xinyu (Zhengzhou University, China)

0
Due to the rapid development of wireless networks, there is a mass of computation requirements for mobile devices. Many computation tasks can be offloaded from networking devices to edge helpers to extend battery life, make efficient use of idling edge computation resources, and address their limitations. This paper provides a convex optimization policy for multiuser computation offloading in the massive MIMO system, which could realize the lower total energy consumption (include local consumption and transmission consumption) in a coherent time. We take into account the user's local computing ability and the channel transmission capacity in the case of binary offloading and partial offloading. For binary offloading, we consider the possibility that individual users cannot compute locally because of limited computing ability. And we always include these users in the offloading list, then turn other offloaded users into locally computed users to use channel capacity more efficiently. Next, in the condition of partial offloading, we reapportion the input data for individual users according to the average channel capacity or maximum local computing ability. Simulation results have shown that the computing resources can be fully utilized without overload and the total energy consumption would be reduced considerably.

Timing Advance Estimation With Robustness to Frequency Offset in Satellite Mobile Communications

Li Zhen (Xi'an University of Posts and Telecommunications, China); Keping Yu (Waseda University, Japan); Guangyue Lu (Xi'an University of Posts & Telecommunications, China); Yukun Zhang (Xi'an University of Posts and Telecommunications, China)

0
Timing advance (TA) estimation based on Zadoff-Chu (ZC) sequences is susceptible to carrier frequency offset (CFO), especially in high-dynamic satellite mobile communication scenarios with large Doppler shift. To solve this problem, a novel random access (RA) preamble sequence is first constructed by combining the real and imaginary part of a root ZC sequence, which entirely inherits the excellent correlation properties of the ZC sequence. With the aim of mitigating the adverse impact of large CFO, we further present a multi-peak joint detection algorithm that can obtain accurate TA value in once correlation operation without additional resource consumption and computational complexities. Numerical results consist with the mathematical analysis, and exhibit the robustness of the proposed method to large CFO in terms of error detection probability (EDP) and timing mean square error (MSE).

Joint Power Allocation for a Novel Positioning-communication Integrated Signal

Lu Yin, Jiameng Cao, Tianrun Jiang and Zhongliang Deng (Beijing University of Posts and Telecommunications, China)

0
This paper develops a positioning-communication joint power allocation method for a novel positioning-communication integrated signal called Multi-Scale Non-Orthogonal Multiple Access (MS-NOMA). One of the main differences between the MS-NOMA and the traditional positioning signal is MS-NOMA supports configurable powers for different positioning users (P-Users) to obtain better ranging accuracy and signal coverage. In this paper, the proposed joint power allocation method minimizes the average range measurement error of all P-Users in the network. Meanwhile, it guarantees QoS (Quality of Services) requirements and total transmit power budget of all users, including P-Users and communication users (C-Users). The numerical results show the effectiveness of the proposed joint power allocation method.

Session Chair

Fan Jiang, Keping Yu

Session WCS-10

Advanced Wireless Techniques IV

Conference
10:30 AM — 12:00 PM CST
Local
Aug 10 Mon, 10:30 PM — 12:00 AM EDT

Comparison of OFDM and SC-FDE for VLC Systems with a Nonlinear LED Model

Hao Zhang (Shandong University, China); Jian Sun (ShanDong University, China); Wensheng Zhang and Zhiquan Bai (Shandong University, China); Cheng-Xiang Wang (Southeast University & Heriot-Watt University, China)

2
Single-carrier frequency domain equalization (SC-FDE) and orthogonal frequency division multiplexing (OFDM) are two attractive technologies for visible light communications (VLC). In this paper, we analyze the two schemes in VLC system with direct current (DC) biasing. We investigate the bit error rate (BER) performance of SC-FDE and OFDM schemes with a memory nonlinear light-emitting diode (LED) model in a simulated indoor scenario. The system performance between both schemes and the impact of LED nonlinear distortion are compared and discussed. We through numerical simulations found that the OFDM scheme exhibits a better BER performance compared to SC-FDE scheme although having a higher peak-to-average power ratio (PAPR).

Transmission Diversity Schemes for Downlink Control Channel in 5G

Qin Mu (Xiaomi Inc, China); Yuqiang Chen, Kexin Xiong and Chenxi Liu (Beijing University of Posts and Telecommunications, China)

0
The 5 th generation(5G) cellular network could provide ever best performance to mobile customers, with higher system capacity, massive connections and lower transmission latency. Physical downlink control channel(CCH) is a core element due to its crucial function to the data transmission in the whole system. In particular, the transmission diversity scheme for downlink control channel is one fundamental aspect to influence the coverage and spectral efficiency. Considering the amount of resources to be used for reference signal will be greatly compressed compared with long term evolution (LTE) system, the existing transmission diversity schemes for CCH, such as spatial frequency block codes (SFBC) and resource element (RE)- based random beamforming would suffer severe block error rate (BLER) loss due to their sensitivity to channel estimation error. To improve the BLER performance, this paper proposes the resource element group (REG) bundle-level random beamforming with the adaptive size of the REG bundle to the aggregation levels of CCH. Moreover, corresponding search space design is further proposed to prevent increase of the CCH blocking. The effectiveness of the proposed methods is validated by link level simulation and numerical analysis.

Delay-Aware Energy Minimization Offloading Scheme for Mobile Edge Computing

Fan Jiang (Xian University of Posts and Telecommunications, China); Fengmiao Wei (Xi'an University of Posts and Telecommunications, Xi'an, China); Junxuan Wang (Xi'an University of Post and Telecommunications, China); Xinying Liu (Keysight Technologies (China) CO., LTD, China)

1
Offloading is regarded as a promising technology to reduce the delay and energy consumption of computation application in Mobile Edge Computing (MEC) network. By considering the demand of request user for low energy consumption and dynamic offloading environment, this paper proposes a offloading strategy by achieving the tradeoff between the energy consumption and time delay of computation application. Specifically, the computation offloading decision is first formulated as a finite horizon Markov decision problem. Then, based on dynamic programming method, a Delay-Aware joint (Device-to-Device) D2D, MEC and Local Offloading (DADMLO) algorithm was proposed to get the optimal offloading policy which aims at minimizing the energy consumption of request user before deadline. Simulation results demonstrate that compared with heuristic schemes, the proposed strategy can complete the computation application with a higher completion probability and lower energy consumption.

An Interference Suppression Method Based on Space-Eigen Adaptive Processing for Satellite Communications

Mengyun Zhao (University of Electronic Science and Technology of China, China); Hongzhi Zhao (UESTC, China); Wenbo Guo and Youxi Tang (University of Electronic Science and Technology of China, China)

1
Aiming at the problem that satellite communications are susceptible to be interfered from every directions, we propose an interference suppression method based on space-eigen adaptive processing (SEAP) to improve the anti-interference capability of satellite receivers. By exploiting the focused distribution characteristics of interference power in eigen domain, the received signals are transformed from time domain to eigen domain for interference suppression, and then inversely transformed back to the time domain for subsequent signal processing. Theoretical analysis and numerical simulation results show that the proposed SEAP algorithm retains the advantage of suppressing interferences in different arriving directions, especially has significant gain for co-directional narrowband interference (NBI).

Cost-Oriented Cooperative Caching Scheme in Energy-Harvesting-Powered Ultra-Dense Networks

Jing Song and Peng Lin (Northeastern University, China); Qingyang Song and Lei Guo (Chongqing University of Posts and Telecommunications, China)

0
Caching contents at wireless edge nodes has been regarded as a promising solution for improving quality of experience (QoE) and reducing energy consumption. Integrating caching to energy-harvesting-powered (EH-powered) ultra-dense small cell networks (UD-SCNs) is an efficient way to alleviate the burdens of backhaul links and further save on-grid energy. In this paper, we propose a cooperative caching scheme which can balance two caching actions, caching the most popular contents and caching diverse contents, in EH-powered UD-SCNs. The former helps reducing transmission delay while the latter contributes to saving on-grid energy. We regard delay and energy as two types of cost and introduce a weighted cost function. Then, the caching problem is transformed to be a cost minimization problem, and a genetic algorithm (GA) is designed to solve the problem in an effective way. Numerical results demonstrate that compared with the existing cooperative caching schemes, the proposed cooperative caching scheme succeeds in balancing transmission delay reduction against on-grid energy saving.

Session Chair

Wensheng Zhang, Jie Yang

Session WCS-08

Advanced Wireless Techniques II

Conference
1:30 PM — 3:00 PM CST
Local
Aug 11 Tue, 1:30 AM — 3:00 AM EDT

On the Node Energy Efficiency of Full Duplex Two-way Ultra-Reliable Short Packet Communications

Zhihao Ye, Zhengchuan Chen, Yunjian Jia and Liang Liang (Chongqing University, China); Min Wang (Chongqing University of Posts and Telecommunications, China)

0
Full-duplex (FD) is a promising technique to improve the spectrum efficiency in wireless communications. However, it is noteworthy that there is a game for both node performances in a two-way channel, since self-interference can not be eliminated completely in FD communications. In this paper, we investigate the node energy efficiency (EE) for FD two-way ultra-reliable short packet communications in an additive white Gaussian noise (AWGN) channel. We focus on two cases. One is that the two nodes are noncooperative, each node only intends to maximize its own EE at any moment. The other one is that two nodes are cooperative, i.e., either of them is willing to improve their optimal EE simultaneously. For the first case, we establish a Game in terms of node EE and design an iterative algorithm to search for a Nash Equilibrium. In the second case, we establish a convex optimization problem of node EE and find the optimal solution by a standard convex optimization algorithm. It is shown by numerical results that the iterative algorithm converges and each node can achieve a higher optimal EE with a lower transmit power if they cooperate with each other.

A Unified Framework for Communications, Computing and Caching Resources Allocation in Mobile Networks

Yingjiao Li, Yaping Sun, Zhiyong Chen, Meixia Tao and Wenjun Zhang (Shanghai Jiao Tong University, China)

0
Mobile services become more and more diversified, that is, there are distinct requirements on the communications, computing and caching (3C) resources in mobile systems. Different from the traditional work that only considers one service type, this paper proposes a unified framework to optimize the 3C resources of base station and mobile devices for diversified services. In the proposed framework, we design a model that the task required by the mobile device to be generated at BS with the mobile edge computing server, the mobile device or both of them to characterize the communication-intensive, computing-intensive and 3C-intensive services. We formulate the optimization problem on the computing and caching resource of the mobile devices and the transmission bandwidth for minimizing the total delay while maximizing the number of the tasks requested and executed by the mobile devices as a multi-objective programming (MOP). Moreover, we propose a single-objective iterative algorithm (SOIA) to this complicated optimization problem, and a quick search algorithm is put forward to obtain the exact Pareto-optimal points in one mobile device scenario. Both algorithms are compared with the traditional multi-objective evolutionary algorithm MOEA/D, and the results show the significant performance in the paper.

PAPR Suppressing Discrete Fourier Transform Precoding-based DSSS-GFDM Transceiver for 5G Satellite Communications

Huanyu Liu, Yuan Jiang and Lin Zhang (Sun Yat-sen University, China)

0
In order to address the issue that the orthogonality could hardly be guaranteed over satellite channels, the generalized frequency division multiplexing (GFDM) has been applied and combined with the direct sequence spread spectrum (DSSS) to combat the carrier frequency offset (CFO). However, due to the superposition of signals over multiple subcarriers, GFDM based systems still suffer from the high peak-to-average power ratio (PAPR). In order to suppress the PAPR while retaining the reliability performances over satellite channels, we propose to utilize the discrete Fourier transform (DFT) precoding to spread the signals in the time domain, thus the probability of superposing signals having the same phase is lowered, thereby leading to the improved PAPR performances. At the receiver, reverse operations are conducted to retrieve the estimates. Furthermore, we analyze the PAPR performances for the proposed design. Then we provide the simulation results to validate that the proposed transceiver could effectively suppress the PAPR performances, while retaining satisfactory BER performances over the additive white Gaussian noise (AWGN) and the international telecommunication union (ITU) satellite channels without or with CFO.

Analysis of UWB Antenna with the MoM Based on RWG-SWG Hybrid Basis Function

Huaijun Zhou and Wei Liu (National University of Defense Technology, China)

0
In view of the insufficient theoretical analysis of UWB antenna by the method of moments (MoM), the detailed process of analyzing UWB antenna by the MoM is presented comprehensively. UWB antenna can be divided into triangle and tetrahedron subdivisions. The surface current distribution is represented by triangle basis function, and the electric displacement vector is represented by tetrahedron basis function. The impedance matrix is divided into four parts: conductor-to-conductor, conductor-to-dielectric, dielectric-to-conductor and dielectric-to-dielectric. The boundary conditions between conductor and dielectric are considered. The formulas for calculating the impedance and current coefficients are obtained. The above algorithm is used to calculate S11 of UWB antenna. The simulated results with FEKO agree well with the results calculated with program, which shows that the algorithm is correct and effective. The realization of this algorithm lays a solid theoretical foundation and provides a good guidance for the optimization and design of UWB antenna.

Particle Swarm Optimization Algorithm based Multi-Path Channel Model Simplification

Mingwei Tang (Beijing University of Posts and Telecommunications, China); Hang Long (Beijing University of Posts & Telecommunications, China); Yixiao Li (Beijing University of Posts and Telecommunications, China)

0
In a system with a large bandwidth, the number of resolvable paths of the channel model is particularly large, making the computer simulation of the channel model and related applications extremely complicated. Therefore, it is necessary to simplify the channel model on the premise of retaining the basic characteristics of the channel. Our goal is to construct a channel model with less paths to approximate the original multi-path channel model, and the absolute error between the frequency correlation functions of the two is used to measure the similarity between them. In this paper, we propose an improved particle swarm optimization algorithm to simplify a multi-path channel. And Lagrangian multiplier method is applied to calculate the power parameters of the simplified channel. Simulation results show that the performance of this algorithm is better than the weighted merger method.

Session Chair

Yunjian Jia, Zhongyuan Zhao

Session WCS-11

Advanced Wireless Techniques V

Conference
1:30 PM — 3:00 PM CST
Local
Aug 11 Tue, 1:30 AM — 3:00 AM EDT

Extended SCMA Graphs for Block Fading Channels

Shannan Mou, Jincheng Dai and Zhongwei Si (Beijing University of Posts and Telecommunications, China)

0
Sparse code multiple access (SCMA) has been considered as one of the candidate techniques to realize non-orthogonal multiuser transmission. In this paper we investigate the SCMA transmission in block fading channels with arbitrary coherent bandwidth. The extension from the SCMA base graph is performed by the cyclic shift of identity matrices. We derive the condition for generating the extended factor graph to combat the block fading, and then we present an algorithm for constructing the superposition matrix simply. Numerical results in terms of symbol error rate is evaluated, which shows that the proposed structure significantly outperforms the base graph and the randomly extended graph. The full diversity can be achieved in block fading channels by following the proposed algorithm.

A Fast Beam Training Method for 5G New Radio

Lei Wang (Beijing Jiaotong University, China); Bo Ai (Beijing Jiaotong University & State Key Lab of Rail Traffic Control and Safety, China); Yong Niu (State Key Laboratory of Rail Traffic Control and Safety, Beijing Jiaotong University, China); Zhangdui Zhong (Beijing Jiaotong University, China); Qi Wang (Huawei Technologies, China); Zhu Han (University of Houston, USA)

0
Millimeter wave communication requires a highly directional transmission link between the base station and the user equipment, which may increase the time of initial access and affect the experience of delay-sensitive users. Considering the initial access technique based on analog beamforming, this paper proposes a fast beam training method for random combination of beam pairs. The method first divides the beam directions of the base station and the user into several groups, and then randomly selects beams from both groups to determine whether it meets the requirement for establishing a link. If so, the algorithm stops the search, otherwise it continues to select beams randomly from the remaining part until a proper beam pair is found. This paper first introduces the beam training process of random combination method, and then compares it with exhaustive method and iterative method in terms of discover delay and misdetection probability. Simulation results show that the random combination method can effectively reduce discover delay and shorten the initial access time.

Recovering Missing Values from Corrupted Historical Spectrum Observations for Dependable Spectrum Prediction

Xi Li, Zhicheng Liu and Yinfei Xu (Southeast University, China); Xin Wang (Stony Brook University, USA); Tiecheng Song (National Mobile Communications Research Laboratory, Southeast University, China)

0
Spectrum prediction is a promising technology to infer spectrum state from historical spectrum observations, by exploiting the inherent correlations and regularities among them. Due to the common existence of missing values and anomalies in the real-world spectrum observations, spectrum prediction with incomplete and corrupted historical observations has caused extensive concern. In this paper, we aim to tackle the challenging problem on how to accurately and efficiently recover the missing values from corrupted historical spectrum observations with which dependable spectrum prediction can be performed. To this end, we first formulate a hankelized time-structured spectrum tensor that can naturally preserve both spectral and temporal dependencies among the historical spectrum observations. Then we model the spectrum data recovery as a tensor completion problem by exploiting its latent low-rank structure and sparse anomaly property. To efficiently solve the optimization problem, we design a robust online spectrum data recovery algorithm based on the alternating direction method. Numerical results demonstrate that the proposed algorithm outperforms state-of-the-art schemes and confirm its effectiveness for dependable spectrum prediction.

Outage Performance Analysis of Full-Correlated Rayleigh MIMO Channels

Huan Zhang (University of Macau, Macao); Guanghua Yang and Zheng Shi (Jinan University, China); Shaodan Ma (University of Macau, China); Hong Wang (Nanjing University of Posts and Telecommunications, China)

0
The outage performance of multiple-input multiple-output (MIMO) technique has received intensive attention to meet the stringent requirement of reliable communications for 5G applications, e.g., mission-critical machine-type communication (cMTC). To account for spatial correlation effects at both transmit and receive sides, the full-correlated Rayleigh MIMO fading channels are modeled according to Kronecker correlation structure in this paper. The outage probability is expressed as a weighted sum of the generalized Fox's H functions. The simple analytical result empowers asymptotic outage analysis at high signal-to-noise ratio (SNR), which not only reveal helpful insights into understanding the behavior of fading effects, but also offer useful design guideline for MIMO configurations. Particularly, the negative impact of the spatial correlation on the outage probability is revealed by using the concept of majorization, and the asymptotic outage probability is proved to be a monotonically increasing and convex function of the transmission rate. In the end, the analytical results are validated through extensive numerical experiments.

Session Chair

Yue Xiu, Hong Wang

Session WCS-09

Advanced Wireless Techniques III

Conference
3:10 PM — 4:40 PM CST
Local
Aug 11 Tue, 3:10 AM — 4:40 AM EDT

A Parallel Carrier Recovery Scheme for an 8Gbps Terahertz Communication System

Yuli Wang, Zhen Qin, Yunsi Ma, Yuanjing Qi and Nan Wu (Beijing Institute of Technology, China)

0
In this paper, a parallel carrier recovery scheme with a large frequency acquisition range of about ¡À50% of the symbol rate is proposed for terahertz communication systems. The proposed scheme is divided into two parts: the frequency offset acquisition based on Mengali and Morelli (M&M) algorithm and the frequency offset tracking employing a decision feedback phase-locked loop. Then, we also design its efficient hardware implementation architecture on Field Programmable Gate Array (FPGA) platform. To improve the utilization of hardware resources, two independent frequency offset compensation modules of the acquisition stage and of the tracking stage are integrated into one offset compensation module. Moreover, an 8 Gbps communication system relying on the proposed parallel carrier recovery scheme is implemented on a Zynq UltraScale+ RFSoC ZUC111 Evaluation Kit. The simulation and implementation results show that the proposed parallel carrier recovery scheme performs well in large carrier frequency offset scenarios and its bit error rate (BER) performance can approach the theoretical curve under 16-ary quadrature amplitude modulation (16-QAM).

Sparse Code Multiple Access with Index Modulation

Chen Zuo and Jianping Zheng (Xidian University, China)

0
In this paper, we study the application of index modulation (IM) to uplink sparse code multiple access (SCMA), and present a scheme called SCMA-IM. In the proposed SCMA-IM, the candidate resources of one user are partitioned into two groups. All the resources in the first group are utilized to transmit signals, and only part of resources in the second are activated through IM to transmit signals. The signals transmitted in these resources are jointly designed according to the same codebook design method as SCMA. Moreover, an effective message passing algorithm is presented to perform the multiuser detection. Simulation results show that the proposed SCMA-IM can achieve better performance than conventional SCMA when the number of receive antenna is large.

Time-reversal ESD for Direction of Arrival Estimation over Multipath channels

Jiawen Lu (Chongqing University of Posts and Telecommunications, China)

0
The fast fading of the signal caused by the multipath effect will cause a large difference in the signal that reaches the receiver at the same time, which seriously affects the effect of the positioning algorithm based on the direction of arrival (DOA). To address this problem, this paper proposes an indoor DOA positioning algorithm based on Time Reversal (TR). This algorithm uses TR technology at the antenna array to focus the wireless signal space-time on the target point to reduce the impact of multipath effects. In addition, it uses Eigenvalue-Subspace Decomposition (ESD) method when analyzing DOA estimates, makes full use of the information of signal subspace and noise subspace to improve the accuracy of DOA estimation. The simulation results show that the positioning algorithm proposed in this paper can improve the positioning accuracy, which is mainly manifested by reducing the lower bound of the system Cramer-Rao and reducing the root mean square error generated during signal estimation.

Performance Analysis for Full-Duplex Networks with Interference Cancellation and Retransmission

Pengcheng Liu, Bin Li, Yixiao Gu and Bin Xia (Shanghai Jiao Tong University, China)

0
This paper investigates the full-duplex (FD) stochastic networks with interference cancellation (IC) and packet retransmission. To distinguish strong and weak interference, we use the concept of strong interference region, and an interference cancellation scheme is adopted to eliminate the uplink (UL) interference from the strong interference region. Moreover, instead of discarding the unsatisfied UL/downlink (DL) request, the packet retransmission mechanism is considered to ensure successful packet transmission, wherein the user's request will remain in the UL/DL buffer head until it is satisfied. That brings the coupled relationship between the UL/DL outage probabilities and buffer empty probabilities. To better analyze the combined impact of IC operation and retransmission in FD networks, we derive the outage probability and the proportions of BSs working in different modes. The simulation results show that in a stochastic FD network with retransmission, IC operation at the DL users not only significantly decreases the DL transmission outage probability but also decreases that of the UL transmission.

Outage Performance of Power Beacon-Assisted Cooperative Hybrid Decode-Amplify-Forward Relaying Wireless Communications

Xinyu Wu and Lu Tang (Yangzhou University, China); Jing Yang (Yangzhou University & Southeast University, China)

0
In this paper, a power beacon (PB) assisted cooperative hybrid decode-amplify-forward (HDAF) relaying wireless communication network is studied. We consider a relaying transmission scheme where the relay may choose to remain silent or transmit information employing decode-and-forward (DF) or amplify-and-forward (AF) protocol based on the qualities of the channels among the source, relay, and destination. In particular, the energy-constrained source and relay harvest energy from radio frequency (RF) signals sent by PB and use the harvested energy to deliver information under the proposed scheme. The closed-form expressions of the outage probability and the throughput over Rayleigh fading channels are derived and demonstrated. Finally, simulations are conducted to convince our theoretical results, and to reveal the impact of the energy harvesting conversion efficency and time allocation factor as well as the outage threshold, which also indicate that the HDAF relaying scheme outperforms the DF and the AF schemes.

Session Chair

Nan Wu, Bin Xia

Session WCS-12

Advanced Wireless Techniques VI

Conference
3:10 PM — 4:40 PM CST
Local
Aug 11 Tue, 3:10 AM — 4:40 AM EDT

An Intellectual Routing Algorithm based on SDN

Qingwen Han (Chongqing University, China); Sheng Cheng (ChongQing University, China); Lingqiu Zeng (Chongqing University, China)

0
With development of vehicular network, BusNet based service is of great interest to both bus company and public users. How to provide service and ensure service quality are considered as key points for the promotion of such kinds of applications. In this paper, a system architecture, which is designed based on Multi-access Edge Computing (MEC) architecture and software-defined network (SDN), is proposed to provide BusNet service. Moreover, a new routing path optimization algorithm, SPSO (serial particle swarm optimization), is proposed, while a dynamic weight matrix is used to improve routing performance. The comprehensive simulation results demonstrate that proposed method can well adapt to the dynamic change of network topology, and improve communication performance significantly.

Power Efficient Finite-Blocklength Transmission over Parallel Fading Channels with Statistical QoS Guarantee

Hongsen Peng (Shanghai Jiaotong University, China); Meixia Tao (Shanghai Jiao Tong University, China)

0
In this paper, we study the power efficient transmission for downlink parallel fading channels under queueing constraints at finite blocklength by leveraging the concept of effective capacity. Firstly we derive the effective capacity by performing rate-adaptive channel coding across the multiple parallel fading channels. Then we adopt two reasonable approximations and obtain a closed-form lower bound of the effective capacity. After that, we investigate the power efficient transmission under statistical QoS constraints based on the closed-form lower bound. Tradeoffs between the total transmit power and the number of the subchannels as well as decoding error probability are identified. In particular, we find that, to maximize the power efficiency, there exists a unique and bounded number of subchannels. Numerical results validate the analytical study and new findings.

Multiuser AF MIMO Multi-Relay System Design with Direct Links and MMSE-DFE Receiver

Yang Lv and Zhiqiang He (Beijing University of Posts and Telecommunications, China); Yue Rong (Curtin University, Australia)

1
Adopting the amplify-and-forward (AF) relay protocol, this paper focuses on the design of a multiuser multiple-input multiple-output (MIMO) multi-relay system with direct source-destination links taken into consideration. In order to improve the quality of signal detection at the receiver, we make use of the minimal mean-squared error (MMSE)-decision feedback equalization (DFE) technique. With the constraints of the signal transmission power at both source and relay nodes, the minimization of the sum mean-squared error (MSE) for the signal waveform estimation of all users' data streams is employed as our design criterion. Through the block coordinate descent (BCD) method of Gauss-Seidel type, we develop an iterative algorithm with guaranteed convergence to conduct the joint optimization of all the source precoding, relay amplifying, feed-forward and decision feedback matrices, where each step we take is to solve a convex problem. It is shown from simulation results that, in comparison to the linear MMSE receiver-based algorithm, the proposed nonlinear one has outstanding performance in terms of both MSE and bit-error-rate (BER). Moreover, the system reliability can be significantly improved when the signal-to-noise ratios (SNRs) of direct links become relatively good.

Multiuser Scheduling for Minimizing Age of Information in Uplink MIMO Systems

He Chen (The Chinese University of Hong Kong, Hong Kong); Qian Wang (University of Sydney, Australia); Zheng Dong (Shandong University, China); Ning Zhang (Texas A&M University-Corpus Christi, USA)

0
This paper studies the user scheduling problem in a multiuser multiple-input multi-output (MIMO) status update system, in which multiple single-antenna devices aim to send their latest statuses to a multiple-antenna information-fusion access point (AP) via a shared wireless channel. The information freshness in the considered system is quantified by a recently proposed metric, termed age of information (AoI). Thanks to the extra spatial degrees-of-freedom brought about by the multiple antennas at the AP, multiple devices can be granted to transmit simultaneously in each time slot. We aim to seek the optimal scheduling policy that can minimize the network-wide AoI by optimally deciding which device or group of devices to be scheduled for transmission in each slot given the instantaneous AoI values of all devices at the beginning of the slot. To that end, we formulate the multiuser scheduling problem as a Markov decision process (MDP). We attain the optimal policy by resolving the formulated MDP problem and develop a low-complexity sub-optimal policy. Simulation results show that the proposed optimal and sub-optimal policies significantly outperform the state-of-the-art benchmark schemes.

Session Chair

Hao Huang, Ning Zhang

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