2016 Proc. IEEE International Conference on Communications, May 23-27, 2016, Kuala Lumpur, Mayalasia.

Space-Time Fronthaul Compression of Complex Baseband Uplink LTE Signals

Jinseok Choi (1), Brian L. Evans (1) and Alan Gatherer (2)

(1) Department of Electrical and Computer Engineering, Wireless Networking and Communications Group, The University of Texas at Austin, Austin, TX 78712 USA
jinseokchoi89@gmail.com - bevans@ece.utexas.edu

(2) Huawei Technologies, Plano, Texas USA

Paper Draft - Slides - Software Release

Related Presentations: Poster (Oct. 16, 2015) - Slides (July 23, 2015)

Multiantenna Communications Project


In this paper, we propose space-time fronthaul compression of baseband uplink LTE signals for cellular networks, in which baseband units (BBUs) support remote radio heads (RRHs) through fronthaul links. In particular, we assume massive antenna arrays in which the number of antennas in a RRH is much larger than the number of active users. The proposed method consists of two phases: dimensionality reduction phase and individual quantization phase. The key idea of the first phase is to apply principal component analysis (PCA). It performs low-rank approximation of a matrix— composed of received signals— by exploiting the correlation of the received signals across space and time. In the second phase, our method individually quantizes the dimensionality-reduced signal by applying transform coding with bit allocation to reduce the number of quantization bits. An LTE link-level simulator provides numerical results which show that the method achieves up to 8× compression ratio for the uplink with 64 antennas and 4 active users, along with improvement in communication system performance as a result of denoising.

Questions & Answers

Question. How can your compression method achieve the SNR gain?

Answer. When we have a low rank matrix Y, low rank approximation can eliminate the subspace which only has noise components, and this achieves noise reduction. And the gain can be measured as G (dB) = 10 log M/L where M is the number of receive antennas, and L is the rank of the matrix Y.

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Last Updated 08/31/16.