Upper-lower bounded-complexity QRD-M for spatial multiplexing MIMO-OFDM systems

TL;DR

This paper introduces ULBC QRD-M, a low-complexity detection algorithm for MIMO-OFDM systems that maintains performance while significantly reducing computational requirements.

Contribution

The paper proposes a novel ULBC QRD-M algorithm that bounds complexity and cancels unnecessary hypotheses, improving efficiency over traditional sphere decoding methods.

Findings

Achieves similar performance to conventional QRD-M

Reduces computational complexity to 26% of traditional methods

Maintains detection accuracy with lower processing requirements

Abstract

Multiple-input multiple-output (MIMO) technology applied with orthogonal frequency division multiplexing (OFDM) is considered as the ultimate solution to increase channel capacity without any additional spectral resources. At the receiver side, the challenge resides in designing low complexity detection algorithms capable of separating independent streams sent simultaneously from different antennas. In this paper, we introduce an upper-lower bounded-complexity QRD-M algorithm (ULBC QRD-M). In the proposed algorithm we solve the problem of high extreme complexity of the conventional sphere decoding by fixing the upper bound complexity to that of the conventional QRD-M. On the other hand, ULBC QRD-M intelligently cancels all unnecessary hypotheses to achieve very low computational requirements. Analyses and simulation results show that the proposed algorithm achieves the performance of conventional QRD-M with only 26% of the required computations.