Multicarrier Division Duplex Aided Millimeter Wave Communications

Abstract

The existing time-division duplex (TDD) and frequency-division duplex (FDD) techniques rely on a guard time and/or a guard band to avoid self-interference (SI) between the uplink and downlink channels, which results in the wastage of precious spectral resources. The full-duplex (FD) schemes of in-band FD (IBFD), as well as multicarrier division duplex (MDD), may overcome this drawback while retaining the key benefits of both TDD and FDD. Moreover, the MDD exhibits the exclusive benefits of the reduced peak-to-average-power ratio (PAPR) for signal transmission as well as the SI-free signal detection. Against this background, in this paper, we propose a novel FD scheme conceived for frequency-selective millimeterwave (mmWave) channels, which have not been investigated in the open literature. Furthermore, we propose a novel projection-aided iterative eigenvalue decomposition (P-IEVD) algorithm, which performs null-space SI cancellation in the inherent beamforming structure of mmWave communication. Our simulation results confirm that the MDD is capable of outperforming its half-duplex (HD) counterparts of the TDD/FDD, even the IBFD can only achieve a better bandwidth efficiency than the MDD when a sufficiently high SNR is provided. INDEX TERMS Full duplex, orthogonal frequency division multiplexing, millimeter wave, uniform linear array, multicarrier division duplex, analog-to-digital converter dynamic range, power-amplifier dynamic range, beamforming, nullspace self-interference cancellation, dynamic subcarrier allocation.

Self-Interference Cancellation and Channel Estimation in Multicarrier-Division Duplex Systems With Hybrid Beamforming

“…Furthermore, in these references, only the point-to-point single-carrier MIMO communication scenarios have been considered. Additionally, in [12], the MDD-assisted point-to-point multicarrier MIMO system employing fulldigital precoder/combiner has been proposed and studied, demonstrating that MDD-mode is capable of outperforming HD and IBFD modes in some communication scenarios. However, when antenna arrays become large, the full-digital SIC methods are no longer feasible in hybird beamforming systems.…”

“…The novelty of our work is compared with the related works in Table 1. Note that in addition to the differences stated in the table, the channel estimation in MDD-based systems was not considered in [12]. The contributions of this paper can be summarized as follows:…”

“…On the other hand, the heterogeneous wireless systems in 5G and beyond will in no doubt rely on multicarrier signaling, in the principles of orthogonal frequency division multiplexing (OFDM) and non-orthogonal multiple access (NOMA). Owing to this consideration, an out-band FD (OBFD) scheme, referred to as multicarrier division duplex (MDD), has been proposed in [10] and further studied in [11,12]. The studies of [12] show that MDD is capable of exploiting the advantages of both FDD and TDD, and employs the potential to outperform both the HD and IBFD schemes in some application scenarios.…”

“…Owing to this consideration, an out-band FD (OBFD) scheme, referred to as multicarrier division duplex (MDD), has been proposed in [10] and further studied in [11,12]. The studies of [12] show that MDD is capable of exploiting the advantages of both FDD and TDD, and employs the potential to outperform both the HD and IBFD schemes in some application scenarios. To be more specific, MDD may be deemed to be a frequency-domain counterpart of TDD and hence, employs all the advantages of TDD.…”

Subcarrier Subset Selection-Aided Transmit Precoding Achieves Full-Diversity in Index Modulation

“…Bearing in mind that the PSK signalling has substantial advantages in terms of both BER performance [55], [56] and PAPR [57], [58] in OFDM-IM systems, we offer the following corollary based on Proposition 1:…”