公开(公告)号：US10999117B2

公开(公告)日：2021-05-04

申请号：US16738897

申请日：2020-01-09

Applicant: APPLE INC.

Inventor： Sameer Pawar ,  Huaning Niu ,  Utsaw Kumar

IPC: H04L27/26

Abstract: Disclosed are apparatuses for communication devices. An apparatus for a communication device includes control circuitry configured to determine a discrete Fourier transform (DFT) of a constant amplitude zero autocorrelation waveform (CAZAC) sequence appended with zeros in the time domain to generate a frequency domain interpolated CAZAC sequence. The control circuitry is also configured to determine an inverse discrete Fourier transform (IDFT) of the frequency domain interpolated CAZAC sequence to generate a demodulation reference signal (DMRS), and cause the DMRS to be transmitted through a cellular data network. An apparatus for a communication device includes control circuitry configured to perform a Fourier transform on a received DMRS to obtain a resulting signal, and use the resulting signal as a reference to demodulate orthogonal frequency-division multiplexing (OFDM) symbols. The control circuitry is also configured to perform a minimum mean squares estimation (MMSE) channel estimation on the resulting signal.

公开(公告)号：US20200287761A1

公开(公告)日：2020-09-10

申请号：US16738897

申请日：2020-01-09

Applicant: APPLE INC.

Inventor： Sameer Pawar ,  Huaning Niu ,  Utsaw Kumar

IPC: H04L27/26

Abstract: Disclosed are apparatuses for communication devices. An apparatus for a communication device includes control circuitry configured to determine a discrete Fourier transform (DFT) of a constant amplitude zero autocorrelation waveform (CAZAC) sequence appended with zeros in the time domain to generate a frequency domain interpolated CAZAC sequence. The control circuitry is also configured to determine an inverse discrete Fourier transform (IDFT) of the frequency domain interpolated CAZAC sequence to generate a demodulation reference signal (DMRS), and cause the DMRS to be transmitted through a cellular data network. An apparatus for a communication device includes control circuitry configured to perform a Fourier transform on a received DMRS to obtain a resulting signal, and use the resulting signal as a reference to demodulate orthogonal frequency-division multiplexing (OFDM) symbols. The control circuitry is also configured to perform a minimum mean squares estimation (MMSE) channel estimation on the resulting signal.