Constant-Amplitude Sequences for Spectrally Compact OFDM Training Waveforms

Constant-amplitude (CA) sequences are desirable to construct training waveforms in orthogonal frequency division multiplexing (OFDM) systems in order to achieve accurate channel estimation and robust initial time and frequency synchronization. However, widely adopted CA pseudorandom-noise and Zadoff-Chu sequences suffer from large power spectral sidelobes and thus render low spectral compactness in OFDM training waveforms. This arouses the design of new CA sequences to provide compact spectrum. In this paper, new CA sequences of length $N$ are developed in explicit sequence expressions for all composite sequence lengths and all prime sequence lengths larger than 11 under all parametric conditions, and shown to provide higher spectral compactness than existing CA sequences.

[1]  Wei-Chang Chen,et al.  Spectrally Efficient OFDM Pilot Waveform for Channel Estimation , 2017, IEEE Transactions on Communications.

[2]  Yong Hoon Lee,et al.  Designing training sequences for carrier frequency estimation in frequency-selective channels , 2006, IEEE Transactions on Vehicular Technology.

[3]  H. Riesel.  Prime numbers and computer methods for factorization , 1985 .

[4]  Michael Faulkner,et al.  The effect of filtering on the performance of OFDM systems , 2000, IEEE Trans. Veh. Technol..

[5]  Yong-Hwan Lee,et al.  Optimum pilot pattern for channel estimation in OFDM systems , 2005, IEEE Transactions on Wireless Communications.

[6]  Xiaojing Huang,et al.  Optimal Orthogonal Precoding for Power Leakage Suppression in DFT-Based Systems , 2011, IEEE Transactions on Communications.

[7]  Khaled Ben Letaief,et al.  A robust timing and frequency synchronization for OFDM systems , 2003, IEEE Trans. Wirel. Commun..

[8]  Petre Stoica,et al.  Training sequence design for frequency offset and frequency-selective channel estimation , 2003, IEEE Trans. Commun..

[9]  Leonard J. Cimini,et al.  Analysis and Simulation of a Digital Mobile Channel Using Orthogonal Frequency Division Multiplexing , 1985, IEEE Trans. Commun..

[10]  David C. Chu,et al.  Polyphase codes with good periodic correlation properties (Corresp.) , 1972, IEEE Trans. Inf. Theory.

[11]  Wei-Chang Chen,et al.  Preamble Sequence Design for Spectral Compactness and Initial Synchronization in OFDM , 2018, IEEE Transactions on Vehicular Technology.

[12]  R. Negi,et al.  Pilot Tone Selection For Channel Estimation In A Mobile Ofdm System * , 1998, International 1998 Conference on Consumer Electronics.

[13]  Wei-Chang Chen,et al.  Pilot Sequence Design for Spectral Compactness and Channel Estimation in OFDM , 2019, 2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall).

[14]  Robert L. Frank,et al.  Polyphase codes with good nonperiodic correlation properties , 1963, IEEE Trans. Inf. Theory.

[15]  Georgios B. Giannakis,et al.  Optimal training and redundant precoding for block transmissions with application to wireless OFDM , 2002, IEEE Trans. Commun..

[16]  Wei-Chang Chen,et al.  Spectrally Precoded OFDM and OFDMA with Cyclic Prefix and Unconstrained Guard Ratios , 2011, IEEE Transactions on Wireless Communications.

[17]  J.J. Benedetto,et al.  Ambiguity Function and Frame-Theoretic Properties of Periodic Zero-Autocorrelation Waveforms , 2007, IEEE Journal of Selected Topics in Signal Processing.