Impact of the propagation environment on the performance of space-frequency coded MIMO-OFDM

Abstract

Previous work on space-frequency coded multipleinput multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) has been restricted to idealistic propagation conditions. In this paper, using a broadband MIMO channel model taking into account Ricean -factor, transmit and receive angle spread, and antenna spacing, we study the impact of the propagation environment on the performance of space-frequency coded MIMO-OFDM. For a given space-frequency code, we quantify the achievable diversity order and coding gain as a function of the propagation parameters. We find that while the presence of spatial receive correlation affects all space-frequency codes equally, spatial fading correlation at the transmit array can result in widely varying performance losses. High-rate space-frequency codes such as spatial multiplexing are typically significantly more affected by transmit correlation than low-rate codes such as space-frequency block codes.We show that in the MIMO Ricean case the presence of frequency-selectivity typically results in improved performance compared to the frequency-flat case.Index Terms-Channel modeling, diversity, multiple-input multiple-output (MIMO), orthogonal frequency-division multiplexing (OFDM), space-frequency coding, spatial multiplexing.

Multiple-Ring Based Modeling and Simulation of Wideband Space-Time-Frequency MIMO Channels

“…Note that this resulting correlation appears in both MIMO in a narrow sense and MIMO in a wide sense 1 . For MIMO in a narrow sense, the aforementioned correlation appears between two arbitrary subchannels of different antennas at different time instant, which are important for the appropriate design of STF coded MIMO-OFDM systems [9]. While for MIMO in a wide sense, this correlation is extremely important for the sensible utilization of the space-frequency diversity [10].…”

“…Therefore, the derived STF CF can explicitly relate the frequency correlation to various propagation parameters (e.g., mean AoA and angle spread). Moreover, based on the derived CF, we reveal the inherent frequency correlation within the spatial correlation, which is important for the design of MIMO frequency diversity systems [9] and [10]. Since the proposed wideband model is a reference model that assumes an infinite number of effective scatterers, it cannot be implemented directly in practice.…”

Combined Time-Reversal Space-Time Block coding and Transmit Beamforming for Frequency-Selective Fading Channels

“…Since there is no closed-form solution for the problem in (6), an SG algorithm is applied to optimize the TR-STBC-rBF-DFE filter vector g numerically based on the gradient vector of the symbol error probability w.r.t. g * , ∂P s (g, v)/∂g * , taken for a random realization of v, which is given by…”

CMI analysis and precoding designs for correlated multi-hop MIMO channels

“…However, this assumption is no longer held true for compact embedded multimedia system design due to the small form factor. The compact system design will cause a MIMO spatial correlation problem [8][9][10][11][12][13], leading to a significant deterioration on the system performance. Furthermore, the pervasive use of computing devices such as laptop computers, PDAs, smart phones, automotive computing devices, wearable computers, and video sensors leads to a fast-growing deployment of wireless mesh networks (WMN) [14] to connect these computing devices by a multi-hop wireless channel.…”