|Budget Amount *help
¥3,500,000 (Direct Cost : ¥3,500,000)
Fiscal Year 2000 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1999 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1998 : ¥1,900,000 (Direct Cost : ¥1,900,000)
The motivation of this research was to develop a novel very high speed (25 to 50 Mbits/sec) multimedia wireless data modulation/demodulation scheme used in pico cells (radius of several tens meters). Using the theory of sequence estimation, we aimed developing a new wireless modem for very high speed nomadic mobile communications.
In each year from 1998 to 2000, the annual plan has been made. As the fundamental modulation/demodulation schemes, the energy detection of continuous phase FSK (CPFSK) and the Limiter/Discriminator detection of CPFSK or GMSK signal, those have very good detection characteristics and also considerable researches have already made by us, have been selected. Based on these non-coherent detection methods and the correlative coding methods at the transmitter side, we tried to propose the final form of wireless communication system. By examining the maximum sequence estimation gain (dB) and the BER characteristics through theoretical study as well as computer simula
tion, I made the objective to propose a novel modulation scheme.
In 1998, I investigated the Limiter/Discriminator detection of binary CPFSK with the sequence estimator and the energy detection of binary CPFSK with the sequence estimator. Through theoretical study and computer simulation, the fundamental theory was established and basic computer simulations were made for the very high speed multimedia wireless modulation scheme.
In 1999, I made the theoretical study of sequence estimation, that is necessary for compensating the inter symbol interference (ISI) due to the superposition of delayed waves on the direct wave and is the main difficulty to overcome to achieve the very high speed wireless communication scheme.
In 2000, the final year, based on the results in previous two years, I applied the soft output Viterbi Algorithm (SOVA) to the Limiter/Discriminator sequence estimation scheme to further improve the BER.Also I made some researches on the Turbo code, a very high efficiency concatenated code. Through theoretical study and computer simulation, the performances were clarified.
As a result of the above studies for three years, the basic proposal in which the constant envelope signal such as CPFSK or GMSK is used as the very high speed wireless multimedia communication signaling has been made.
The research results from 1998 to 2000 are reported as two IEICE Transaction papers (all reviewed), six IEEE international conference papers (all reviewed) and one oral presentation paper (non-reviewed), some of them are referenced in the following back page. Less