학술논문

An All-Digital, Single-Bit RF Transmitter for Massive MIMO
Document Type
Periodical
Source
IEEE Transactions on Circuits and Systems I: Regular Papers IEEE Trans. Circuits Syst. I Circuits and Systems I: Regular Papers, IEEE Transactions on. 64(3):696-704 Mar, 2017
Subject
Components, Circuits, Devices and Systems
Pulse width modulation
Radio frequency
Encoding
MIMO
Mobile communication
Radio transmitters
5G
all-digital
ASIC
delta-sigma modulation
FPGA
massive MIMO
mobile communications
pulsewidth modulation
signal processing
switch-mode
transceiver
Language
ISSN
1549-8328
1558-0806
Abstract
This paper presents an all-digital transmitter solution particularly suited for Massive multiple-input and multiple-output (MIMO) systems for mobile communications. Massive MIMO is a key candidate to address the challenges of future mobile communication standards, especially to provide higher capacity in dense urban scenarios. While the required communication theory is elaborated to a great extend, the transceiver hardware complexity remains a potential economical show-stopper. This paper demonstrates that all-digital transmitters can be employed to reduce size, cost, and engineering effort of heavily parallelized transmit architectures. Therefore, today’s all-digital transmitter concepts are analyzed and improvements are suggested to increase performance and feasibility. The realized setups prove that the key specifications of mobile communication standards can be met utilizing dedicated integrated circuits or even by using off-the-shelf FPGAs and their high-speed interfaces. We show that we can generate 8 parallel 5 MHz LTE signals at 2.6 GHz out of a single FPGA with an ACPR of 48 dB with a coding efficiency of 50% using only binary waveforms.