Frequency-shift keying (FSK) is a popular modulation scheme in power-limited communication links. This paper introduces space-time FSK (ST-FSK), which does not require any channel state information at the transmitter and the receiver, as in conventional noncoherent FSK. ST-FSK can be viewed as a special unitary ST modulation design. However, ST-FSK has a number of advantages over existing unitary ST modulation designs. ST-FSK is easier to design, and enjoys lower decoding complexity. Furthermore, ST-FSK guarantees full diversity. Finally, ST-FSK can be adopted in the digital as well as in the analog domain, and merges very naturally with frequency-hopping multiple access. As expected, all these advantages come at the cost of a decrease in spectral efficiency.
Bibliographical noteFunding Information:
Paper approved by W. E. Ryan, the Editor for Modulation, Coding, and Equalization of the IEEE Communications Society. Manuscript received October 31, 2002; revised August 11, 2003 and September 15, 2003. This work was supported in part by the National Science Foundation Wireless Initiative under Grant 9979443, in part by the Army Research Lab/Collaborative Technology Alliance (ARL/CTA) under Grant DAAD19-01-2-011, in part by the FWO-Vlaanderen, and in part by the Bog˘aziçi University Research Fund under Contract 00A202. This paper was presented in part at the 36th Conference on Information Sciences and Systems, Princeton, NJ, March 2002.
- Frequency-shift keying (FSK)
- Orthogonal design
- Space-time (ST) coding
- Unitary modulation