A Direct-Conversion Digital Beamforming Array Receiver with 800 MHz Channel Bandwidth at 28 GHz using Xilinx RF SoC

Abstract

This paper discusses early results associated with a fully-digital direct-conversion array receiver at 28 GHz. The proposed receiver makes use of commercial off-the-shelf (COTS) electronics, including the receiver chain. The design consists of a custom 28 GHz patch antenna sub-array providing gain in the elevation plane, with azimuthal plane beamforming provided by real-time digital signal processing (DSP) algorithms running on a Xilinx Radio Frequency System on Chip (RF SoC). The proposed array receiver employs element-wise fully-digital array processing that supports ADC sample rates up to 2 GS/second and up to 1 GHz of operating bandwidth per antenna. The RF mixed-signal data conversion circuits and DSP algorithms operate on a single-chip RF SoC solution installed on the Xilinx ZCU1275 prototyping platform.

JCR70: A Low-Complexity Millimeter-Wave Proof-of-Concept Platform for a Fully-Digital SIMO Joint Communication-Radar

“…The next step is to develop a fully-digital mmWave multipleinput-multiple-output prototype with real antenna array and parallel low-resolution RF chains. Fully digital mm-wave beamforming is an open research area and there is already some progress [29], [30]. The fully-digital mmWave MIMO prototype can be used in a dynamic scenario, to demonstrate its capability for next-generation high-performance automotive and drone applications.…”

“…The development of a prototype with a real antenna array and parallel RF chains for dynamic testing with velocity estimation is a subject of future work. Fully digital mm-wave beamforming is an open research area and there is already some progress [29], [30].…”

Software-Defined Radio Beamforming System for 5G/Radar Applications

“…However, it requires heavy digital signal processing (DSP) MIMO operations to retrieve the information. A similar concept was recently shown in [16], proposing a digital array receiver for satellite applications, also integrating DSP algorithms, operating in a single-chip RF system on chip (SoC) solution installed on the Xilinx ZCU1275 prototyping platform; however, operating in a fixed frequency range between 27.5 and 28.35 GHz. A 64-channel massive MIMO transceiver with a fully digital beamforming (DBF) architecture is presented in [17].…”

“…The concept of beamforming, in the sense of the ability to control the radiation shape of an antenna array, can be performed either digitally, like the examples presented previously [14][15][16][17][18][19], analogically (by using the frontend analog phase shifters [20]) or in a hybrid way [21]. A millimeter-wave hybrid beamforming system architecture based on analog phased subarray is reported in [22].…”

“…This work uses a 32-element antenna array with a hybrid beamforming transceiver to operate at the 28 GHz band in TDD mode, with 500 MHz bandwidth. An important aspect is the reduction in the number of intermediate frequency (IF) channels compared to [14][15][16][17][18][19], reducing the cost comparing to fully digital architectures. However, one issue with this architecture is the analog phase shifting, which is critical to increasing the insertion loss up to 19.5 dB, requiring the use of additional amplifiers to compensate such losses.…”