Eiichiro Kawakami

Multi-stage interference canceller systems with accurate radio channel estimation under fading environment

This paper proposes multi-stage interference canceller systems (MSICS) which can estimate radio channels with precision in direct sequence code division multiple access (DS-CDMA) systems. For accurate channel estimation, we propose a novel radio channel estimation method specified by the following two signal processing methods. One is the radio channel estimation method using both pilot and information signals. The other is the correction method of the estimated radio channels using adaptation algorithms. The results of our computer simulations indicate that the cell capacity of the proposed MSICS in a serial and parallel structure can be increased by about 1.8 and 1.3 times over that of a receiver which does not have a canceller, respectively. Moreover, the proposed MSICS in a serial and parallel structure can reduce the required E/sub b//N/sub o/ by about 1.2 dB and 1.6 dB at a BER of 10/sup -3/ compared to the E/sub b//N/sub o/ of a conventional MSICS, respectively.

Multi-stage interference canceller using adaptive signal processing

This paper proposes the structures of multi-stage interference cancellers, which make the replica of each user and each path to cancel from received signal. In our proposed multi-stage method, the replica and the residual signal are sent to the next stage. In this method, the interference by other paths of an assigned user is very small because the replica is combined after the correlation detection. In order to estimate each radio channel accurately, we propose the correction method of the radio channel estimation by adaptive signal processing. We show the BER performance and cell capacity of our proposed method quantitatively by computer simulations.

A Wireless Video Home-Link Using 60 GHz Band: A Study of Non-linear Distortion

This paper investigates video signal degradation factors caused by intermodulation products from mixers or other non-linear devices of the video transmission system for wireless home-links, which transmits communications satellite (CS), broadcasting satellite (BS), and terrestrial broadcasting in the VHF band video signals. The second-and third-order intercept points for the non-linear devices are calculated from the view of the desired to undesired signal power ratio (DUR) of each video signal.

Burst error reduction method of a CDMA multimedia system

This paper presents evaluation results of the performance of a burst error reduction method (BERM) of a CDMA multimedia system. The BERM is made up of anti-fading technologies including path diversity reception (PDR), transmitting power control (TPC) and an interleaver and the de-interleaver for an error control. The number of PDR branches, the TPC rate, the TPC step and interleaver length of the BERM and the service area size of a broadband data transmission system are evaluated to develop the CDMA multimedia system.