Impact on Inter-Cell Interference of Reference Signal for Interference Rejection Combining Receiver in LTE-Advanced Downlink

This paper investigates the dominant impact on the interference rejection combining (IRC) receiver due to the downlink reference signal (RS) based covariance matrix estimation scheme. When the transmission modes using the cell-specific RS (CRS) in LTE/LTE-Advanced are assumed, the property of the non-precoded CRS is different from that of the data signals. This difference poses two problems to the IRC receiver. First, it results in different levels of accuracy for the RS based covariance matrix estimation. Second, assuming the case where the CRS from the interfering cell collides with the desired data signals of the serving cell, the IRC receiver cannot perfectly suppress this CRS interference. The results of simulations assuming two transmitter and receiver antenna branches show that the impact of the CRS-to-CRS collision among cells is greater than that for the CRS interference on the desired data signals especially in closed-loop multiple-input multiple-output (MIMO) systems, from the viewpoint of the output signal-to-interference-plus-noise power ratio (SINR). However, the IRC receiver improves the user throughput by more than 20% compared to the conventional maximal ratio combining (MRC) receiver under the simulation assumptions made in this paper even when the CRS-to-CRS collision is assumed. Furthermore, the results verify the observations made in regard to the impact of inter-cell interference of the CRS for various average received signal-to-noise power ratio (SNR) and signal-to-interference power ratio (SIR) environments

Progress of New Heavy-ion Treatment Facility at NIRS

Since 1994, the carbon beam treatment has been continued at Heavy Ion Medical Accelerator in Chiba (HIMAC). Based on more than ten years of experience with HIMAC, we have developed a new heavy-ion treatment facility toward an adaptive cancer therapy.The fast 3D scanning system including the moving target irradiation was installed in the new facility. It is also equipped with the image guided system. It allows the scanning irradiation on the trunk of the body. The rotating gantry will be also installed in the facility. It adopts the superconducting magnets to reduce the size and the weight of the gantry.The treatment for the fixed target has been provided since 2011 in the two rooms and the number of the patient reaches 300 per year. The treatment for the moving target is scheduled to start in 2014. The superconducting rotating gantry is under construction now and the treatment will be started 2016.The new heavy-ion treatment facility at NIRS has been gradually developed and all machines will be installed and all three treatment rooms will be opened a few years later.53rd Annual Conference of the Particle Therapy Co-Operative Group (PTCOG53