Title :
Alamouti-type Space-Time coding for TH-UWB systems with unipolar Pulse Position Modulations
Author :
Abou-Rjeily, Chadi ; Bkassiny, Mario
Author_Institution :
Dept. of Electr. & Comput. Eng., Lebanese American Univ., Byblos
Abstract :
In this paper, we consider the problem of space-time (ST) coding with unipolar pulse position modulations (PPM). The proposed code satisfies a large number of construction constraints that render it superior to the existing PPM encoding schemes. In particular, the proposed 2 times 2 code achieves a full transmit diversity order while transmitting at a rate of 1 PPM-symbol per channel use. The proposed scheme can be associated with M-ary PPM constellations for all even values of M without introducing any constellation extension. This renders the proposed scheme suitable for low cost carrier-less ultra-wideband (UWB) systems where information must be conveyed only by the time delays of the modulated sub-nanosecond pulses without introducing any amplitude amplification or phase rotation. Finally, the proposed scheme is symbol-by-symbol decodable where the information can be reconstituted by performing simple linear operations at the receiver side. A possible extension to transmitters equipped with three antennas is also discussed in situations where a certain number of feedback bits is available.
Keywords :
diversity reception; pulse position modulation; space-time codes; ultra wideband communication; Alamouti-type space-time coding; M-ary PPM constellations; TH-UWB systems; amplitude amplification; antennas; feedback bits; linear operations; phase rotation; subnanosecond pulses; symbol per channel use; time-hopping ultrawideband systems; transmit diversity order; unipolar pulse position modulations; Amplitude modulation; Costs; Decoding; Delay effects; Modulation coding; Phase modulation; Pulse amplifiers; Pulse modulation; Transmitters; Ultra wideband technology;
Conference_Titel :
Personal, Indoor and Mobile Radio Communications, 2008. PIMRC 2008. IEEE 19th International Symposium on
Conference_Location :
Cannes
Print_ISBN :
978-1-4244-2643-0
Electronic_ISBN :
978-1-4244-2644-7
DOI :
10.1109/PIMRC.2008.4699406