Near-Field Low-WISL Unimodular Waveform Design for Terahertz Automotive Radar

Eamaz, Arian; Yeganegi, Farhang; Mishra, Kumar Vijay; Soltanalian, Mojtaba

doi:10.48550/arxiv.2303.04332

Cited by 1 publication

(2 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, for ease of implementation, we assume that if an EH or ID receiver is scheduled, the BS will steer a beam towards it to maximize its received power based on e.g., codebook based beamforming, i.e., v ID m = a (θ m ) and v EH k = b (θ k , r k ). 3 Under the above assumptions, the achievable rate of each ID receiver m can be rewritten as (12) shown on the bottom of the next page, and the harvested power at each EH receiver k is given by…”

Section: B Problem Formulationmentioning

confidence: 99%

“…With the significant increase of carrier frequency and number of antennas, the well-known Rayleigh distance is going to expand to dozens or even hundreds of meters. This thus leads to a fundamental paradigm shift in the electromagnetic (EM) field characteristics, from the conventional far-field communications towards the new near-field communications [12], [13]. Specifically, different with far-field communications whose EM field can be approximated as planar waves, the radio propagation in near-field communications should be accurately modeled by spherical waves.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

6G Wireless Communications: From Far-Field Beam Steering to Near-Field Beam Focusing

et al. 2023

View full text Add to dashboard Cite

Extremely large-scale array (XL-array) has emerged as a promising technology to enhance the spectrum efficiency and spatial resolution in future wireless networks by exploiting massive number of antennas for generating pencil-like beamforming. This also leads to a fundamental paradigm shift from conventional far-field communications towards the new nearfield communications. In contrast to the existing works that mostly considered simultaneous wireless information and power transfer (SWIPT) in the far field, we consider in this paper a new and practical scenario, called mixed near-and far-field SWIPT, where energy harvesting (EH) and information decoding (ID) receivers are located in the near-and far-field regions of the XL-array base station (BS), respectively. Specifically, we formulate an optimization problem to maximize the weighted sum-power harvested at all EH receivers by jointly designing the BS beam scheduling and power allocation, under the constraints on the maximum sum-rate and BS transmit power. First, for the general case with multiple EH and ID receivers, we propose an efficient algorithm to obtain a suboptimal solution by utilizing the binary variable elimination and successive convex approximation methods. To obtain useful insights, we then study the joint design for special cases. In particular, we show that when there are multiple EH receivers and one ID receiver, in most cases, the optimal design is allocating a portion of power to the ID receiver for satisfying the rate constraint, while the remaining power is allocated to one EH receiver with the highest EH capability. This is in sharp contrast to the conventional far-field SWIPT case, for which all powers should be allocated to ID receivers. Numerical results show that our proposed joint design significantly outperforms other benchmark schemes without the optimization of beam scheduling and/or power allocation.Index Terms-Simultaneous wireless information and power transfer (SWIPT), extremely large-scale array (XL-array), mixed near-and far-field channels, beam scheduling, power allocation.

show abstract

Section: B Problem Formulationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%