Title :
Multicarrier spread spectrum system with constant envelope: antijamming, jamming estimation, multiuser access
Author :
Tan, Jun ; Stüber, Gordon L.
Author_Institution :
Georgia Inst. of Technol., Atlanta, GA, USA
fDate :
7/1/2005 12:00:00 AM
Abstract :
A special complex sequence called a complex quadratic sequence is proposed as the frequency-spreading sequence for the multicarrier spread-spectrum (MC-SS) modulation scheme. The resulting MC-SS signal has constant envelope in both time and frequency domains. This feature provides flexibility for the MC-SS system to mitigate the effects of both partial-band and pulse jamming. For partial-band jamming, the MC-SS system with frequency domain detection and combining can outperform direct sequence spread spectrum. For pulse jamming, the MC-SS system with time-domain detection and combining can outperform other MC-SS systems. The proposed MC-SS signal has a constant envelope, thus, reducing linearity requirements on the power amplifier. A simple jammer state estimation scheme for both partial-band and pulse-jamming channels is also proposed. Furthermore, multiaccess with the MC-SS system is possible by assigning users different cyclic-shifts of the complex quadratic sequence.
Keywords :
frequency-domain analysis; jamming; multiuser detection; spread spectrum communication; time-domain analysis; antijamming; complex quadratic sequence; constant envelope; cyclic-shift; direct sequence spread spectrum; frequency domain detection; frequency-spreading sequence; jammer state estimation scheme; jamming estimation; multicarrier spread spectrum modulation scheme; multiuser access; partial-band jamming; power amplifier; pulse jamming; time domain detection; Collaboration; Frequency domain analysis; Frequency estimation; Jamming; OFDM; Power amplifiers; Pulse amplifiers; Spread spectrum communication; State estimation; US Government; Multicarrier spread spectrum; spread spectrum modulation;
Journal_Title :
Wireless Communications, IEEE Transactions on
DOI :
10.1109/TWC.2005.850382