Multiuser MIMO receivers for space frequency block coded SC‐FDMA systems

Abstract

SummarySingle carrier‐frequency division multiple access (SC‐FDMA) has been adopted as the uplink transmission standard in fourth generation cellular network to enable the power efficiency transmission in mobile station. Because multiuser MIMO (MU‐MIMO) is a promising technology to fully exploit the channel capacity in mobile radio network, this paper investigates the uplink transmission of SC‐FDMA systems with orthogonal space frequency block codes (SFBC). Two linear MU‐MIMO receivers, orthogonal SFBC (OSFBC) and minimum mean square error (MMSE), are derived for the scenarios with limited number of users or adequate receive antennas at base station. In order to effectively eliminate the multiple access interference (MAI) and fully exploit the capacity of MU‐MIMO channel, we propose a turbo MU‐MIMO receiver, which iteratively utilizes the soft information from maximum a posteriori decoder to cancel the MAI. By the simulation results in several typical MIMO channels, we find that the proposed MMSE MU‐MIMO receiver outperforms the OSFBC receiver over 1 dB at the cost of higher complexity. However, the proposed turbo MU‐MIMO receivers can effectively cancel the MAI under overloaded channel conditions and really achieve the capacity of MU‐MIMO channel. Copyright © 2014 John Wiley & Sons, Ltd.

A low‐complexity turbo MUD for MU–MIMO SC‐FDMA systems

“…For the general case of SFBC with U users, each user employs N t transmit antennas, K frequency transmit diversity and M receive antennas in the base station, for the general case in , if we want to obtain the signal of the user one, we can pre‐multiply V 1 by and divide it by . Afterward, we can subtract X (1) from V m , 2≤ m ≤ M in by and dividing by .…”

“…where Q R is the upper triangular matrix and Q is the orthogonal matrix. Once Equation (26) has been obtained, simplified demodulation algorithms can be applied, the likelihood metric is 27) where the 2 Á are provided in [13]. Based on the previous expression, we can employ the backward recursion algorithm that slices along all symbols for the lowest layers.…”

Resource allocation for SC‐FDMA based cognitive radio systems

“…This motivates the development of algorithms that guarantees the challenging adjacency constraint on subcarrier assignment. Resource allocation in the context of SC-FDMA systems has also been quite well studied (e.g., [22][23][24][25][26][27][28][29]). However, these works do not consider CR-based SC-FDMA systems.…”