Towards less-than-one reuse factor: space-time MIMO turbo equalizers system-level simulation results

Current advances in multi-dimensional channel sounding techniques make it possible to evaluate performances of signal processing algorithms in realistic conditions. By using channel impulse response measurement data collected in the real fields, link-level performances of the signal processing algorithms in the fields such as bit error rate (BER) and frame error rate (FER) performances can be evaluated. This technique is called link-level simulation. Through statistical analysis of link-level simulation results, system-level performances of space/time (S/T) equalizers; such as SINR and BER distributions in the area of interest can also be evaluated. This technique is called system-level simulation. This paper focuses on link- and system-level performances of S/T- and MIMO turbo-equalizers in real fields. Methodologies for the link- and system-level simulations using field measurement data are first presented. Results of link- and system-level simulations using two-dimensional channel sounding field measurement data collected in Tokyo are then presented. The assumption made in this paper is that multiple users aim to transmit their signals using the same time- and frequency-slots without spreading their signals in the frequency domain, which is an ultimate goal of cellular mobile communication engineering. It is shown that S/T- and MIMO turbo equalizers make this ultimate goal realistic.