Dynamic grouped chip-level iterated multiuser detection based on Gaussian forcing technique

The brute-force MAP-based Chip-Level Iterated (CLi) Multiuser Detection techniques exploiting the newly proposed Low-Density Signature (LDS) structure have been shown to approach the performance of Single-User even at overloading condition of up to 200%. However, their complexity is exponential to the number of interfering users in a chip that can be impractical. In this letter, by using Gaussian-Forcing (GF) technique, we trade-off performance and complexity and it results in a dynamic Grouped GF (G-GF) CLi MUD technique. We show via computer simulation, at the system with 200% condition, the loss of approximately 0.3 dB compared to its brute-force counterpart is observed while reducing the complexity to more than half.