[Paper Review] Millimeter-wave Gbps Broadband Evolution towards 5G: Fixed Access and Backhaul

Zhouyue Pi, Junil Choi+1 more|arXiv (Cornell University)|Jul 14, 2015

Millimeter-Wave Propagation and Modeling4 references4 citations

TL;DR

This paper proposes a Millimeter-wave Gbps Broadband (MGB) system using 39 GHz spectrum, dynamic beamforming, and massive MIMO to enable high-capacity fixed wireless access and small cell backhaul. With 500 MHz bandwidth and 28 dBm transmit power (55 dBm EIRP), the system achieves over 11 Gbps backhaul capacity for 96 small cells within a 1-km radius, demonstrating feasibility for 5G Gbps infrastructure.

ABSTRACT

As wireless communication evolves towards 5G, both fixed broadband and mobile broadband will play a crucial part in providing the Gbps infrastructure for a connected society. This paper proposes a Millimeter-wave Gbps Broadband (MGB) system as the solution to two critical problems in this evolution: last-mile access for fixed broadband and small cell backhaul for mobile broadband. The key idea is to use spectrum that is already available in the millimeter wave bands for fixed wireless access with optimized dynamic beamforming and massive MIMO infrastructure to achieve high capacity with wide area coverage. This paper explains the MGB concept and describes potential array architectures for realizing the system. Simulations demonstrate that with 500 MHz of bandwidth (at 39 GHz band) and 28 dBm transmission power (55 dBm EIRP), it is possible to provide more than 11 Gbps backhaul capacity for 96 small cells within 1-km radius.

Motivation & Objective

• To address the last-mile broadband access challenge in 5G by leveraging underutilized millimeter wave spectrum.
• To solve small cell backhaul capacity constraints in mobile broadband networks using high-bandwidth mmWave links.
• To enable wide-area, high-capacity wireless connectivity through optimized beamforming and massive MIMO infrastructure at 39 GHz.
• To demonstrate the feasibility of delivering multi-Gbps backhaul capacity for dense small cell deployments.

Proposed method

• Utilizes 500 MHz of bandwidth in the 39 GHz millimeter wave band for high spectral efficiency.
• Employs dynamic beamforming to focus signals toward user equipment, enhancing link reliability and capacity.
• Deploys massive MIMO arrays at base stations to spatially multiplex multiple data streams.
• Models the system with 28 dBm transmit power (55 dBm EIRP) to ensure sufficient coverage and link budget.
• Uses realistic path loss and shadowing models to simulate performance in urban-like environments.
• Analyzes system capacity under realistic deployment constraints, including interference and beam alignment.

Experimental results

Research questions

• RQ1 Can millimeter wave spectrum at 39 GHz support multi-Gbps backhaul capacity for dense small cell deployments?
• RQ2 How does dynamic beamforming improve coverage and spectral efficiency in mmWave fixed wireless access systems?
• RQ3 What is the achievable capacity of a massive MIMO-based mmWave system under realistic propagation conditions?
• RQ4 Can a single base station serve multiple small cells with high data rates using beamforming and wide bandwidth?
• RQ5 What system parameters (bandwidth, power, array size) are required to achieve Gbps-level backhaul capacity?

Key findings

• With 500 MHz bandwidth at 39 GHz and 28 dBm transmit power (55 dBEIRP), the MGB system achieves over 11 Gbps backhaul capacity for 96 small cells within a 1-km radius.
• Dynamic beamforming significantly improves signal reliability and spectral efficiency in line-of-sight and non-line-of-sight scenarios.
• Massive MIMO enables spatial multiplexing, allowing simultaneous transmission to multiple small cells without significant interference.
• The system maintains high data rates even with moderate path loss and shadowing, demonstrating robustness in urban-like environments.
• The results confirm that mmWave spectrum can support the Gbps infrastructure required for 5G fixed and mobile broadband.
• The proposed MGB system is a viable solution for both last-mile fixed access and small cell backhaul in 5G networks.