RF Lens-Embedded Massive MIMO Systems: Fabrication Issues and Codebook Design

Abstract

Abstract-In this paper, we investigate a radio frequency (RF) lens-embedded massive multiple-input multiple-output (MIMO) system and evaluate the system performance of limited feedback by utilizing a technique for generating a suitable codebook for the system. We fabricate an RF lens that operates on a 77 GHz (mmWave) band. Experimental results show a proper value of amplitude gain and an appropriate focusing property. In addition, using a simple numerical technique-beam propagation method (BPM)-we estimate the power profile of the RF lens and verify its accordance with experimental results. We also design a codebook-multi-variance codebook quantization (MVCQ)-for limited feedback by considering the characteristics of the RF lens antenna for massive MIMO systems. Numerical results confirm that the proposed system shows significant performance enhancement over a conventional massive MIMO system without an RF lens.Index Terms-Massive MIMO, RF lens antenna, beam propagation method, limited channel feedback, multi-variance codebook quantization method.

Millimeter-Wave MIMO Prototype: Measurements and Experimental Results

“…1(a). 8 With beamforming being a central component in meeting the mm-Wave link budget, RF component and architecture-driven challenges (e.g., cost, power, complexity, form factor, regulatory constraints, etc.) play a principal role in determining practically viable hybrid beamforming solutions.…”

“…Important issues that require further study include: i) a more exhaustive study on realistic channel modeling for mm-Wave propagation, ii) models for spatio-temporal channel variations, iii) models for impairments such as hand/body/human blockages, phase noise, etc., iv) advanced MIMO techniques for both single-and multi-user multi-carrier transmissions, v) impact of mm-Wave channel properties on mm-Wave system/network design issues such as coverage and network latency tradeoffs, mm-Wave handover, interworking with sub-6 GHz bands and applications, integrated access-bachkaul solutions, vi) advanced MIMO RF architectures such as [5]- [8] for prototype studies and real deployments, vii) RF tradeoffs in form factor UE design, etc.…”

Golden angle‐inspired design of massive MIMO tapered slot array with less correlation for 5G lower band applications

“…Here, the smaller sections of patch arrays were placed in a hexagonal fashion in three layers to reduce the spatial correlation. A RF lens‐embedded MIMO system was reported in Reference , operates on a 77‐GHz band, shown to improve the effective diversity order by improving the focusing ability. RF Lens‐enabled receiver provides two new benefits, namely, electromagnetic (EM) energy focusing and the ability to reject spatial interference.…”

“…Very few implementations of massive MIMO were reported [11][12][13][14][15][16][17][18][19][20] till now in the literature which has just proved the workability of the technique. A dual-polarized 288-element antenna array with 144 ports for massive MIMO operating at 3.7 GHz which corresponds to the lower 5G bands is presented in References 11 and 12.…”

“…But, these massive MIMO antenna designs [11][12][13][14][15][16][17][18][19][20] were not densely packed and available space is not utilized efficiently. After we came across all the available ideas and from the problem reported in Reference 18 about possible to pack many antennas in a small space, it is realized that nowhere, no design was seem to be reported about achieving the optimized space occupancy of antenna elements of the massive MIMO.…”