An efficient low PAPR training sequence design scheme under spectral constraints in mm-Wave OFDM communication

This work investigates the design scheme of orthogonal frequency division multiplexing (OFDM) training sequences with low peak to average power ratio (PAPR) under spectral constraints. Sequences with low PAPR can be used for synchronization and channel estimation in communication systems. In practical systems, there are always spectral constraints such as the reserved tones and DC-offset subcarriers. Meanwhile, millimeter-wave (mm-Wave) communication is rising as a key technology to provide high data rates with wide bandwidth (BW) in future wireless communication systems. As the tenfold increase in carrier frequency, the RF hardware is becoming more sensitive to the PAPR. This work aims to design a training sequence with lower PAPR under spectral constraints which is a non-convex problem. Specially, a design scheme based on cross entropy considering the spectral constraints to obtain an efficient binary constant envelope training sequence with low PAPR is presented. Eventually, we design a channel estimation training sequence in view of the detailed IEEE 802.11aj application scenario which involved the spectral constrains. Finally, the simulation result demonstrates that the proposed scheme is an advisable approach to design training sequence in practical communication system. The application derived from the scheme has been adopted in IEEE 802.11aj.