Creating and sharing knowledge for telecommunications

Optimal design of perfect DFT sequences

Pereira, J. ; Silva, H. A.

Physical Communication Vol. 7, Nº -, pp. 92 - 104, June, 2013.

ISSN (print): 1874-4907
ISSN (online):

Journal Impact Factor: 0,802 (in 2015)

Digital Object Identifier: 10.1016/j.phycom.2012.10.001

Abstract
In this paper, we propose a novel scheme to construct a large set with N(N+1) perfect sequences of length N, derived from an Inverse Discrete Fourier Transform (IDFT) of Chu and maximum-length sequences. This optimum set of perfect periodic autocorrelation sequences has a maximum absolute value of periodic cross correlation strictly lower than N and close to the well known lower bound SQRT(N). Moreover, we present a method to transform these perfect sequences into orthogonal sequences. A similar method is also proposed to obtain optimum bipolar codes derived from an alternative set of NxN perfect sequences.
In the design of perfect sequences, the difficulty is to achieve both low cross-correlation and low peak-to-average power ratio (PAPR). Many of the proposed perfect DFT sequences should have low PAPR and thus can be applied in an OFDM-CDMA (Orthogonal Frequency-Division Multiplexing - Code Division Multiple Access) communication system or in a simple CDMA communication system. Alternatively, the proposed perfect DFT sequences may be useful for pre-coded mapping in OFDM communication systems or for the design of radar waveform diversity sets.