Methods, apparatuses and systems directed to unique word discrete fourier transform spread and shaped orthogonal frequency division multiplexing based transmissions

Patent metadata

Field	Value
Publication number	US-2020052947-A1
Application number	US-201716090570-A
Country	US
Kind code	A1
Filing date	Mar 30, 2017
Priority date	Mar 31, 2016
Publication date	Feb 13, 2020
Grant date	—

Abstract

Methods, apparatuses, systems, devices, and computer program products directed to unique word (UW) discrete Fourier transform (DFT) spread and shaped orthogonal frequency division multiplexing (OFDM) (“UW DFT-S-S-OFDM”) based communications are provided. Among new methodologies and/or technologies provided is a method that may be implemented in transmitter and that may include any of: transforming a set of data symbols and a UW sequence into a frequency domain (“fDOM”) signal using a DFT; replicating the fDOM signal so as to form a plurality of fDOM signal instances, wherein the plurality of fDOM signal instances is inclusive of the fDOM signal; shaping one or more of the plurality of fDOM signal instances; combining the plurality of fDOM signal instances to form a combined fDOM signal; transforming the combined fDOM signal into a block-based signal using an inverse DFT (IDFT); and outputting the block-based signal.

First claim

1 . A method implemented in transmitter comprising:
transforming a set of data symbols and a unique word (UW) sequence into a frequency domain (“f DOM ”) signal using a discrete Fourier transform (DFT); replicating the f DOM signal so as to form a plurality of f DOM signal instances, wherein the plurality of f DOM signal instances is inclusive of the f DOM signal; shaping each of the plurality of f DOM signal instances; combining the plurality of f DOM signal instances to form a combined f DOM signal; transforming the combined f DOM signal into a block-based signal using an inverse DFT (IDFT); and outputting the block-based signal.

2 . The method of claim 1 , wherein the combined f DOM signal is mapped to a set of subcarriers.

3 . The method of claim 2 , wherein combining the plurality of f DOM signal instances to form a combined f DOM signal comprises mapping the plurality of f DOM signal instances to a respective plurality of subsets of the set of subcarriers.

4 . The method of claim 3 , wherein at least one of the subsets of the plurality of subsets is not mutually exclusive from at least one other subset of the plurality of subsets.

5 . The method of claim 2 , wherein combining the plurality of f DOM signal instances to form a combined f DOM signal comprises mapping the plurality of f DOM signal instances to a respective plurality of adjacent, non-overlapping subsets.

6 . The method of claim 1 , wherein the DFT and the IDFT have respective sizes, wherein the size of the IDFT (IDFT size) is larger than the size of the DFT (DFT size), wherein the plurality of f DOM signal instances is a number, k, of instances, and wherein the number, k, corresponds to a ratio of the IDFT size to the DFT size.

7 . The method of claim 1 , wherein shaping the plurality of f DOM signal instances comprises any of:
filtering each of the plurality of f DOM signal instances; and performing frequency-domain windowing on the plurality of f DOM signal instances.

8 . The method of claim 1 , wherein shaping each of the plurality of f DOM signal instances comprises applying to the plurality of f DOM signal instances a respective plurality of components of a filter.

9 . The method of claim 8 , wherein the plurality of components of a filter are rotated with a respective plurality of complex coefficients.

10 . The method of claim 7 , wherein performing frequency domain windowing comprises:
multiplying the plurality of f DOM signal instances with a filter having frequency response that suppresses one or more samples of one or more of the plurality of f DOM signal instances.

11 . The method of claim 10 , wherein the filter has a length that is less than or equal to a number of time domain samples that corresponds to an internal guard interval.

12 . The method of claim 11 , wherein the internal guard interval is based on an up-sampling factor, and wherein the up-sampling factor corresponds to a ratio of the IDFT size to the DFT size.

13 . The method of claim 7 , wherein performing frequency domain windowing comprises:
multiplying the plurality of f DOM signal instances with a filter having sidelobes smaller than a Dirichlet sinc function.

14 . A transmitter comprising a discrete Fourier transform (DFT) unit, a processing unit and an inverse DFT (IDFT) unit, wherein:
the DFT unit is configured to transform a set of data symbols and a unique word (UW) sequence into a frequency domain (“f DOM ”) signal using a DFT; the processing unit is configured to:
replicate the f DOM signal so as to form a plurality of f DOM signal instances, wherein the plurality of f DOM signal instances is inclusive of the f DOM signal;
shape each of the plurality of f DOM signal instances;
combine the plurality of f DOM signal instances to form a combined f DOM signal; and
the IDFT unit is configured to:
transform the combined f DOM signal into a block-based signal using an IDFT; and
output the block-based signal.

15 . The transmitter of claim 14 , wherein the processing unit is configured to shape the plurality of f DOM signal instances, at least in part, by any of:
filtering each of the plurality of f DOM signal instances; and performing frequency-domain windowing on the plurality of f DOM signal instances.

16 . The transmitter of claim 15 , wherein the processing unit is configured to perform frequency domain windowing, at least in part, by:
multiplying the plurality of f DOM signal instances with a frequency domain filter having a frequency response of a corresponding time domain filter.

17 . The transmitter of claim 16 , wherein the frequency response is based on the time domain filter having a length that is less than or equal to a number of time domain samples that corresponds to an internal guard interval.

18 . A method implemented in transmitter comprising:
transforming a first set of data symbols and a first unique word (UW) sequence into a first frequency domain (“f DOM ”) signal using a first discrete Fourier transform (DFT); replicating the first f DOM signal so as to form a plurality of first f DOM signal instances, wherein the plurality of first f DOM signal instances is inclusive of the first f DOM signal; shaping each of the plurality of first f DOM signal instances; combining the plurality of first f DOM signal instances to form a first combined f DOM signal; transforming a second set of data symbols and a second UW sequence into a second f DOM signal using a second DFT; replicating the second f DOM signal so as to form a plurality of second f DOM signal instances, wherein the plurality of second f DOM signal instances is inclusive of the second f DOM signal; shaping each of the plurality of second f DOM signal instances; combining the plurality of second f DOM signal instances to form a second combined f DOM signal; adding the first combined f DOM signal and the second combined f DOM signal to form a third f DOM signal; transforming the third f DOM signal into a block-based signal using an inverse DFT (IDFT); and outputting the block-based signal.

19 . The method of claim 18 , wherein the third f DOM signal is mapped to a set of subcarriers.

20 . The method of claim 18 , wherein:
the third f DOM signal is mapped to a set of subcarriers; combining the plurality of first f DOM signal instances to form a first combined f DOM signal comprises mapping the plurality of first f DOM signal instances to the set of subcarriers; and combining the plurality of second f DOM signal instances to form a second combined f DOM signal comprises mapping the plurality of second f DOM signal instances to the set of subcarriers.

21 . The method of claim 18 , wherein:
the third f DOM signal is mapped to a set of subcarriers; a sample of the first combined f DOM signal is mapped to a subcarrier of the set of subcarriers; a sample of the second combined f DOM signal is mapped the same subcarrier of the set of subcarriers; and adding the first combined f DOM signal and the second combined f DOM signal to form a third f DOM signal comprises adding the sample of the first combined f DOM signal and the sample of the second combined f DOM signal.

22 . The method of claim 18 , wherein:
the third f DOM signal is mapped to a set of subcarriers; combining the plurality of first f DOM signal instances to form a first combined f DOM signal comprises mapping the plurality of first f DOM sig

Assignees

• Idac Holdings Inc

Inventors

• Sahin Alphan
• Bala Erdem
• Yang Rui
• Beluri Mihaela C
• Olesen Robert L

Classifications

• H04L5/0007

  the frequencies being orthogonal, e.g. OFDM(A) or DMT · CPC title

• H04W72/0453

  Resources in frequency domain, e.g. a carrier in FDMA · CPC title

• H04L27/2636 Primary

  with FFT or DFT modulators, e.g. standard single-carrier frequency-division multiple access [SC-FDMA] transmitter or DFT spread orthogonal frequency division multiplexing [DFT-SOFDM] · CPC title

• H04L27/26 Primary

  Systems using multi-frequency codes (H04L27/32 takes precedence) · CPC title