Title :
Implementation of ASK-OFDM Exploiting the Property of Symmetry
Author_Institution :
Res. In Motion Ltd., Ottawa, ON
Abstract :
A method to implement OFDM using amplitude shift keying (ASK) for subcarrier modulation is presented in this paper. Because ASK is used, the signal of each symbol in the time domain is conjugate-symmetric. This property is exploited such that only half of the numbers of each symbol sequence are transmitted. The generated baseband signal can be a complex or a real signal. ASK-OFDM has similar bandwidth efficiency and the same error rate performance in an AWGN channel as in a QAM-OFDM. Compared with QAM-OFDM, ASK-OFDM provides a method of distributing signal energy more evenly in the frequency band. In other words, ASK-OFDM signal possesses better frequency diversity than QAM-OFDM signal.
Keywords :
AWGN channels; OFDM modulation; amplitude shift keying; diversity reception; subcarrier multiplexing; time-domain analysis; ASK-OFDM; AWGN channel; amplitude shift keying; bandwidth efficiency; baseband signal generation; conjugate-symmetric sysmbol; error rate performance; frequency diversity; subcarrier modulation; symbol sequence; time domain analysis; AWGN channels; Amplitude modulation; Amplitude shift keying; Bandwidth; Baseband; DSL; Digital video broadcasting; Error analysis; OFDM modulation; Quadrature amplitude modulation;
Conference_Titel :
Vehicular Technology Conference, 2006. VTC-2006 Fall. 2006 IEEE 64th
Conference_Location :
Montreal, Que.
Print_ISBN :
1-4244-0062-7
Electronic_ISBN :
1-4244-0063-5
DOI :
10.1109/VTCF.2006.298
