In-Band Full-Duplex Relay-Assisted Millimeter-Wave System Design

Abstract

Millimeter-wave (mmWave) communication is a promising technology for future wireless systems due to the availability of huge unlicensed bandwidth. However, the need for large number of radio frequency (RF) chains associated with the antenna array and the corresponding increase in hardware complexity and power consumption are major stumbling blocks to its implementability. In this paper, we propose a low-complexity in-band full-duplex relay-assisted mmWave communication system design. We obtain the proposed multiple-input multiple-output analog-digital hybrid transceivers and relay filters by minimizing the overall sum-mean-square-error while mitigating the effect of residual loopback self-interference (LSI) in the system. The number of RF chains required in the proposed design is less than the number of antennas. We first present a design assuming the availability of perfect channel state information (CSI) at all the nodes. Later, we extend it to a robust design assuming a more realistic scenario, where the available CSI is imperfect. Furthermore, the LSI channel knowledge is assumed to be imperfect for both the designs rendering them robust to errors in loopback CSI. We employ sparse approximation technique to reduce the hardware complexity in the proposed system designs. The proposed algorithms are shown to converge to a limit even though the global convergence is hard to prove since the overall problem is nonconvex. The hardware complexity-performance tradeoff of the proposed design is analyzed. Furthermore, the resilience of the robust design in the presence of CSI errors and the performance of both the proposed designs over various parameters are illustrated via numerical simulations. INDEX TERMSFull-duplex, hybrid beamforming, millimeter-wave communication, residual self-interference, robust design.

Robust Joint Hybrid Analog-Digital Transceiver Design for Full-Duplex mmWave Multicell Systems

“…In particular, they derived an approximation of the average received signal-to-noise-ratio (SNR) as the objective function, and developed an OMP-based algorithm. The work of [35] considered the imperfection of loopback self-interference knowledge and proposed a sparse approximation technique to reduce the hardware complexity. In [36], a robust joint transceiver algorithm was proposed for a FD mmWave MIMO relay system in the presence of stochastic CSI errors.…”

Pilot Sequence Design for mmWave Cellular Systems With Relay Stations in the Presence of Blockage

“…The rate maximization problem with the per antenna power constraints is solved while taking into account the computational complexity and sparse characteristics of mmWave channels. Jagyasi and Ubaidulla [23] proposed device-to-device (D2D) relaying and low-complexity mmWave system architecture to alleviate the blockage problem in mmWave bands and improve user experience consistency. Wu et al [24] discussed two-hop D2D relaying for mmWave cellular networks when infrastructure relay is not available.…”

An alternating direction algorithm for hybrid precoding and combining in millimeter wave MIMO systems

“…Regarding the hybrid design, it was shown in [8] that the number of RF chains only needs to be twice the number of data streams in order to achieve the exact performance of the fully digital beamforming architecture. To deal with the cases where the number of RF chains is lower than twice the number of data streams, several heuristic algorithms have been proposed covering different scenarios namely, point-to-point MIMO [7], [9]- [15], multiuser downlink MIMO with single [16] or multiple receiver antennas per user [8], [17]- [19], multiuser uplink [20], multi-cell multiuser [21], general multiuser MIMO interference channels [22] and relay-assisted mmWave systems [23] [24]. In this paper we will focus our study on point-to-point MIMO systems.…”