|Budget Amount *help
¥11,000,000 (Direct Cost: ¥11,000,000)
Fiscal Year 2003: ¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 2002: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2001: ¥6,500,000 (Direct Cost: ¥6,500,000)
The purpose of this research is to develop a high speed digital wireless communication system (25 to 30 Mega bits/sec) for ITS inter-vehicle communications. Especially by using the theory of sequence estimation for digital FM signals, we aimed to develop a novel high speed wireless modulation and demodulation scheme which has very strong anti-multipath characteristics.
In the year 2001, Turbo equalization scheme for GMSK or GFSK signal using frequency detection was proposed. In the proposed scheme, we had used the MAP (BCJR) algorithm, Log-Map algorithm or Max-Log-Map algorithm for the inner ISI SISO (Soft Input/ Soft Output) decoding (Y.IWANAMI). Also a multi-beam di-electric lens antenna which has the beam width of 4 degrees and the scanning angle of 15 degrees was developed and tested, succeeded to get the desired results (H.Kida). In the year 2002, the study on the sequence estimation scheme of FSK signals using energy detection, which is the another scheme proposed, had almost been
completed for the special binary FSK signal case. In addition to it, we had developed the sequence estimation scheme with energy detection for M-ary FSK signals, which is basically the extension of the case for binary FSK (Y.IWANAMI). Furthermore, using Matlab from Mathworks corp. and a SignalMaster from Lyr Signal Processing corp., which is a DSP hardware set, we made the estimation of complexity of the hard ware in order to reduce the complexity of the receiver (Y.IWANAMI). A lens horn antenna for 60GHz which has the square cosecant characteristic for the elevation angle and have low radiation to direction of the road surface was developed for the use of inter vehicle communication or vehicle to access point communication (H.Kida). In the year 2004, we had made more precise analysis and design for MFSK energy sequence estimation receiver. Even though we had already proposed a 16FSK energy sequence estimation receiver in the previous year, more exact analysis and design was made to refine the receiver performance (Y.IWANAMI). On the other hand, the matching layer was added to the lens horn antenna for 60GHz to improve the objective designed values (H.Kida).
From the above research results spanning over 3 years, two major proposed schemes, i.e., Turbo equalizer with frequency detection for GMSK and GFSK signals, and MFSK energy sequence estimation receiver have been developed. Also the evaluation of complexity of the receiver structure was done using DSP sets and a lens horn antenna for inter vehicle communication was developed. Thus we had made the important research for high speed wireless data transmission system for ITS inter-vehicle communication. The research results are reported through the total 6 journal or conference papers written in English listed in the next page. Less