High Throughput Constant Envelope Pre-coder for Massive MIMO Systems

Summary, in English

This study describes a high throughput constant envelope (CE) pre-coder for Massive MIMO systems. A large number of antennas (M), in the order of 100s, serve a relatively small number of users (K) simultaneously. The stringent amplitude constraint (only phase changes) in the CE scheme is motivated by the use of highly power-efficient non-linear RF power amplifiers. We propose a scheme that computes the CE signals to be transmitted based on box-constrained regression (coordinatedescent),with an O(2MK) complexity per iteration per user

symbol. A highly scalable systolic architecture is implemented, where M Processing Elements (PEs) perform the pre-coding for a system with up to K = 16 users. This systolic architecture results in a very high throughput of 500 Msamples/sec (at 500 MHz clock rate) with a gate count of 14 K per PE in 65 nm technology.

• Author: Hemanth Prabhu; Fredrik Rusek; Joachim Rodrigues; Ove Edfors
• Department/s: Department of Electrical and Information Technology; ELLIIT: the Linköping-Lund initiative on IT and mobile communication
• Publishing year: 2015
• Language: English
• Publication/Series: 2015 IEEE International Symposium on Circuits and Systems (ISCAS)
• Full text: - 292 kB; Download statistics
• Links: http://dx.doi.org/10.1109/ISCAS.2015.7168930
• Document type: Conference paper
• Publisher: IEEE - Institute of Electrical and Electronics Engineers Inc.
• Topic: Electrical Engineering, Electronic Engineering, Information Engineering
• Keywords: massive mimo; pre-coding; constant envelope; gradient descent
• Conference name: IEEE International Symposium on Circuits and Systems (ISCAS), 2015
• Conference date: 2015-05-24 - 2015-05-27
• Conference place: Lisbon, Portugal
• Status: Published
• Project: Distributed antenna systems for efficient wireless systems
• Research group: Digital ASIC
• ISBN/ISSN/Other: ISBN: 978-1-4799-8391-9