Search for OFDM synchronization waveforms with good aperiodic autocorrelations
Canadian Conference on Electrical and Computer Engineering; Technology Driving Innovation, 2004, Niagara Falls, Canada, 2 - 05 May 2004, vol.1, pp.13-18, (Full Text)
- Publication Type: Conference Paper / Full Text
- Volume: 1
- City: Niagara Falls
- Country: Canada
- Page Numbers: pp.13-18
- Keywords: Evolutionary search, Good aperiodic autocorrelated waveforms, OFDM frame synchronization
- Ankara University Affiliated: Yes
Abstract
In this paper, the problem of searching for OFDM synchronization waveforms with good aperiodic autocorrelation properties is addressed. A synchronization waveform is embedded within data in the form of pilot tones. Selection of the sub-channel locations to be reserved for synchronization pilots is critical, as each different selection will result in a waveform with a different sidelobe pattern. The optimal pilot tone location selection problem is mathematically intractable and an exhaustive search for practical systems is infeasible. In this work, a genetic algorithm is employed for searching the locations of a number of pilot tones among all OFDM subcarriers such that the resulting time waveform has good autocorrelation properties. The performance of the generated synchronization waveforms was evaluated in a simulated OFDM system and it was demonstrated that they achieve the desired frame synchronization performance. It was observed that the genetic algorithm accomplishes the task much faster than a random search.