Title :
Proposal of FSK modulated spread spectrum systems for enhancing frequency utilization efficiency
Author :
Kuroyanagi, Noriyoshi ; Guo, Lili ; Suehiro, Naoki ; Ohtake, Kohei
Author_Institution :
Tokyo Eng. Univ., Japan
Abstract :
In contrast with direct sequence-spread spectrum, an M-ary system characterized by frequency shift keying-spread spectrum (FSK-SS) is proposed. FSK-SS is comprised of two modulation stages; one selecting a frequency to represent the multiple levels, and the other multiplying a code sequence with the frequency. The shift frequencies are selected in a range less than the chip frequency, while satisfying an orthogonal relationship. Practical design examples show that FSK/BPSK-SS is able to achieve 1.4~2.7 times larger capacity than that of conventional DS-SS. The interference tolerant capability is also discussed
Keywords :
binary sequences; codes; frequency shift keying; radiofrequency interference; spread spectrum communication; FSK modulated spread spectrum systems; FSK-SS; FSK/BPSK-SS; M-ary system; capacity; chip frequency; code sequence; frequency shift keying-spread spectrum; frequency utilization efficiency; interference tolerant capability; shift frequencies; Correlators; Electronic mail; Frequency estimation; Frequency shift keying; Interference; Modulation coding; Proposals; Pulse modulation; Spread spectrum communication; Transmitters;
Conference_Titel :
Personal, Indoor and Mobile Radio Communications, 1994. Wireless Networks - Catching the Mobile Future., 5th IEEE International Symposium on
Conference_Location :
The Hague
Print_ISBN :
90-5199-193-2
DOI :
10.1109/WNCMF.1994.529476
