scholarly journals Joint Beamforming and Interference Cancellation in MmWave Wideband Full-Duplex Systems

2021 ◽  
Author(s):  
Elyes Balti

Full-duplex (FD) systems have the capability to transmit and receive at the same time in the same frequency band.FD systems can reduce congestion and latency and improve coverage and spectral efficiency.As a relay, they can increase range and decrease outages.Full-duplex (FD) wireless systems have been emerging as a practical solution to provide high bandwidth, low latency, and big data processing in millimeter wave and Terahertz systems to support cellular networks, autonomous driving, platooning, advanced driving assistance and other systems. However, FD systems suffer from loopback self-interference that can swamp the analog-to-digital converters (ADCs) resulting in very low spectral efficiency. In this context, we consider a cellular system wherein uplink and downlink users independently communicate with FD base station. The proposed contributions are (1) three hybrid beamforming algorithms to cancel self-interference and increase the received power, and (2) evaluation of outage probability, spectral efficiency, and energy efficiency of the proposed algorithms. We consider full-digital beamforming and upper bound as benchmarks. Finally, we show the resiliency of Algorithm 2 against self-interference in comparison with Algorithms 1 and 3, as well as conventional approaches such as beam steering, angle search and singular value decomposition.

2021 ◽  
Author(s):  
Elyes Balti

Full duplex (FD), which allows bidirectional transmission over the same resources, has the potential to reduce latency and double spectral efficiency. Recently, FD has been studied in 5G LTE millimeter wave cellular communications for New Radio in 3GPP releases 15--17. The primary drawback of FD is self-interference (SI). SI arises in the receiver for system 1 because it receives transmissions from itself and system 2. Because system 1 is much closer, SI can be 100-1000x the received power from system 2, thereby severely degrading communication. In this paper, we investigate a FD relay extending mmWave coverage to a single user. We propose to use alternating projections in designing the precoder and combiner to maximize the sum of the uplink and downlink spectral efficiency while bringing the SI below the noise floor. Our contributions include (1) all-digital and hybrid beamforming design algorithms for SI cancellation; and (2) communication performance analysis in terms of spectral efficiency, energy efficiency and outage probability. We compare the proposed algorithms against beam steering, singular value decomposition, and angle search techniques.


Electronics ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 172
Author(s):  
Jiahao Zhang ◽  
Fangmin He ◽  
Wei Li ◽  
Yi Li ◽  
Qing Wang ◽  
...  

Increased demand for higher spectrum efficiency, especially in the space-limited chip, base station, and vehicle environments, has spawned the development of full-duplex communications, which enable the transmitting and receiving to occur simultaneously at the same frequency. The key challenge in this full-duplex communication paradigm is to reduce the self-interference as much as possible, ideally, down to the noise floor. This paper provides a comprehensive review of the self-interference cancellation (SIC) techniques for co-located communication systems from a circuits and fields perspective. The self-interference occurs when the transmitting antenna and the receiving antenna are co-located, which significantly degrade the system performance of the receiver, in terms of the receiver desensitization, signal masking, or even damage of hardwares. By introducing the SIC techniques, the self-interference can be suppressed and the weak desired signal from the remote transmitter can be recovered. This, therefore, enables the full-duplex communications to come into the picture. The SIC techniques are classified into two main categories: the traditional circuit-domain SICs and the novel field-domain SICs, according to the method of how to rebuild and subtract the self-interference signal. In this review paper, the field-domain SIC method is systematically summarized for the first time, including the theoretical analysis and the application remarks. Some typical SIC approaches are presented and the future works are outlooked.


Wireless phones which receive their signals from towers. A cell is typically the area (several miles) around a tower in which a signal can be received. Cell phones provide array of functions. Depending on the type of mobile phone we can store contact information, keep track of appointments and set reminders, Use the built-in calculator for simple math, send or receive e-mail, get information (news, entertainment, stock quotes) from the internet, play games, watch TV, send text messages, integrate other devices such as PDAs, MP3 players and GPS receivers. A cell phone is a full-duplex device meaning that both people on the call can talk at once. Division of a city into small cells allows extensive frequency reuse across a city, so that millions of people can use cell phones simultaneously. Cell phones operate within cells, and they can switch cells as they move around. Cells give cell phones incredible range. Someone using a cell phone can drive hundreds of miles and maintain a conversation the entire time because of the cellular approach. Each cell has a base station that consists of a tower and a small building containing the radio equipment. The cell phones have evolved from Analog to Digital which has been described in the previous chapter. This chapter describes the two main standards for mobile phones i.e. GSM and WAP.


Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6472
Author(s):  
Hoang Van Toan ◽  
Tran Manh Hoang ◽  
Tran Trung Duy ◽  
Le The Dung

In this paper, we consider a two-user downlink full-duplex (FD) non-orthogonal multiple access (NOMA) relay system where the FD relay uses an energy harvesting (EH) technique to assist the communication between the base station and far user over flat, independent and non-identically Rayleigh fading channels. Importantly, since the relay operates in FD mode, we take into account the effect of the interference caused by relay on the near user. Considering this EH-FD-NOMA relay system, we derive the exact mathematical expressions of the outage probabilities and ergodic capacities of near and far users. Monte–Carlo simulations verify the accuracy of our analytical method. Numerical results provided in this paper allow system designers to clearly see not only the impacts of the power distribution factor and the self-interference cancellation capacity of the relay but also the influence of the strength of inter-user interference at the near user on the outage performances and ergodic capacities of both users.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2768
Author(s):  
Asmaa Amer ◽  
Abdel-Mehsen Ahmad ◽  
Sahar Hoteit

In this paper, the interplay between non-orthogonal multiple access (NOMA), device-to-device (D2D) communication, full-duplex (FD) technology, and cooperation networks is proposed, and a resource allocation problem is investigated. Specifically, a downlink FD cooperative NOMA-based cellular system with underlaying D2D communications is proposed, where, in each NOMA group, the strong user assists the weak user as an FD relay with imperfect self interference (SI) cancellation. In terms of reaping spectral efficiency benefits, the system sum rate is to be maximized by optimizing channel allocation. This optimization is based on quality of service (QoS) constraints of D2D pairs and cellular users (CUs), power budget of base station and strong user (cooperative phase), and successive interference cancellation (SIC) constraints. Since the maximization formulated problem is computationally challenging to be addressed, a two-sided stable many-to-one matching algorithm, based on Pareto improvement, performs sub-channel assignment. Extensive simulations are implemented to demonstrate the system performance indicated by different metrics.


2007 ◽  
Vol 20 (1) ◽  
pp. 45-55
Author(s):  
Veljko Stankovic

In this paper we introduce a novel linear preceding technique. It was previously reported in the literature that when the user terminals are equipped with one antenna, minimum mean-squared-error (MMSE) in combination with successive interference cancellation is optimum on the uplink, while MMSE preceding in combination with Tomlinson-Harashima preceding (THP) is optimum on the downlink. The linear preceding technique introduced in this paper is based on the modified MSB criterion. It can serve the users that are equipped with arbitrary number of antennas with only limitation that the total number of users in the system has to be less than or equal to the rank of the combined multiple-input multiple-output (MIMO) channel matrix of all users. It was shown in the simulations that it extracts very high diversity gain and at low signal-to-noise ratios, when the total number of antennas at the user terminals is greater than the number of antennas at the base station, it approaches the maximum sum rate capacity of the broadcast channel. The technique introduced in this paper is favorable for practical implementation since it requires by an order of magnitude less operations than the techniques based on the singular value decomposition.


Author(s):  
Mai Thi Phuong Le ◽  
Hung Le Nguyen ◽  
Hieu Van Nguyen ◽  
Vien Duy Nhat Nguyen

In this paper, we investigate the spectral efficiency (SE) of a multi-user multiple-input multiple-output (MU-MIMO) antenna network in full-duplex (FD) regime, where uplink (UL) and downlink (DL) users simultaneously share the same time and frequency resources. Zero-forcing approach is applied efficiently to precode/detect signals in both UL and DL. To achieve the SE maximization, we formulate an optimized problem where the transmit power of Base station (BS) and users are jointly considered. Numerical results are used to show that the proposed algorithm may bring significant SE gain over the previous approaches under realistic channel conditions.


Electronics ◽  
2021 ◽  
Vol 10 (20) ◽  
pp. 2456
Author(s):  
Masaud Shah ◽  
Hammad M. Cheema ◽  
Qammer H. Abbasi

In-band full duplex offers a new approach of meeting the ever-increasing data rate demands by operating the transmitter and receiver at the same frequency at the same time, potentially doubling the spectral efficiency. However, self-interference is the fundamental bottleneck of such systems. In contrast to non-planar or sub 6 GHz microstrip designs reported so-far, this paper presents an all SIW based antenna system for in-band full duplex systems. The proposed design integrates a dual linear polarized three port differential antenna, three port SIW common-mode power combiner and a 180°phase shifter at 28 GHz. Operating the antenna in TE201 mode provides inherent isolation between the differential receive and single-ended transmit port. The residual coupling is further reduced through use of TE101 based power combiner and a 180°phase shifter. Implemented on a 0.508 mm thick RT Duroid 5880 substrate, the antenna occupies a foot-print of 48 × 80 mm2. Demonstrating a measured gain of 6.95 dBi and 3.42 dBi for Tx and Rx mode of operation, respectively, the proposed design offers a self-interference cancellation (SiC) of better than 36 dB over a 177 MHz bandwidth.


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