MIMO channel modelling and simulation for cellular and mobile-to-mobile

Abstract

Recently, mobile-to-mobile (M2M) communications have received much attention due to several emerging applications, such as wireless mobile ad hoc networks, relay-based cellular networks, and dedicated short range communications (DSRC) for intelligent transportation systems (e.g., IEEE 802.11p standard). Different from conventional fixed-to-mobile (F2M) cellular systems, in M2M systems both the transmitter (Tx) and receiver (Rx) are in motion and often equipped with low elevation antennas. Multiple-input-multiple-output (MIMO) technologies, employing multiple antennas at both the Tx and Rx, have widely been adopted for the third generation (3G) and beyond-3G (B3G) F2M cellular systems due to their potential benefits of improving coverage, link reliability, and overall system capacity. More recently, MIMO has been receiving more and more attention for M2M systems as well. Reliable knowledge of the propagation channel obtained from channel measurements and corresponding channel models serve as the enabling foundation for the design and analysis of MIMO F2M and M2M systems. Furthermore, the development of accurate MIMO F2M and M2M channel simulation models plays a major role in the practical simulation and performance evaluation of these systems. These form the primary motivation behind our research on MIMO channel modelling and simulation for F2M cellular and M2M communication systems. In this thesis, we first propose a new wideband theoretical multiple-ring based MIMO regular-shaped geometry-based stochastic model (RS-GBSM) for non-isotropic scattering F2M macro-cell scenarios and then derive a generic space-time-frequency (STF) correlation function (CF). The proposed theoretical reference wideband model can be reduced to a narrowband one-ring model, a new closed-form STF CF of which is derived as well. Narrowband and wideband sum-of-sinusoids (SoS) simulation models are then developed, demonstrating a good agreement with the corresponding reference models in terms of correlation functions. Secondly, based on a well-known narrowband two-ring single-input single-output (SISO) M2M channel reference model, we propose new deterministic and stochastic SoS simulation models for non-isotropic scattering environments. The proposed deterministic simulator is the first SISO M2M deterministic simulator with good performance, while the proposed stochastic simulator outperforms the existing one in terms of fitting the desired statistical properties of the corresponding reference model. Thirdly, a new adaptive narrowband MIMO M2M RS-GBSM is proposed for nonisotropic scattering environments. To the best of our knowledge, the proposed M2M model is the first RS-GBSM that has the ability to study the impact of the vehicular traffic density on channel statistics. From the proposed theoretical reference model, we comprehensively investigate some important M2M channel statistics including the STF CF, space-Doppler-frequency power spectral density, envelope level crossing rate, and average fade duration. A close agreement between some channel statistics obtained from the proposed reference model and measurement data is observed, confirming the utility of our model. Finally, we extend the above narrowband model to a new wideband MIMO M2M RSGBSM with respect to the frequency-selectivity. The proposed wideband reference model is validated by observing a good match between some statistical properties of the theoretical model and available measurement data. From the wideband reference model, we further design new wideband deterministic and stochastic SoS simulation models. The proposed wideband simulators can be easily reduced to narrowband ones. The utilities of the newly derived narrowband and wideband simulation models are validated by comparing their statistical properties with those of the corresponding reference models. The proposed channel reference models and simulators are expected to be useful for the design, testing, and performance evaluation of future MIMO cellular and M2M communication systems.