Communication system for transforming signals between time domain and frequency domain using a defined discrete fourier transform size

Patent metadata

Field	Value
Publication number	US-10743315-B2
Application number	US-201916596199-A
Country	US
Kind code	B2
Filing date	Oct 8, 2019
Priority date	Sep 22, 2008
Publication date	Aug 11, 2020
Grant date	Aug 11, 2020

Abstract

A communication system includes a communication apparatus and a base station. The communication apparatus includes a Discrete Fourier Transform (DFT) transformer which transforms a time-domain signal into a frequency-domain signal with a DFT size that is a product of powers of a plurality of values; a mapper which maps the frequency-domain signal on a plurality of frequency bands, each frequency band being located at a position separate from position(s) of other(s) of the plurality of frequency bands; and a signal generator which generates a single carrier-frequency division multiple access (SC-FDMA) time-domain signal from the mapped signal. The base station includes a receiver which receives the SC-FDMA time-domain signal; a combiner which generates the frequency-domain signal from the SC-FDMA time-domain signal; and a transformer which transforms the frequency-domain signal into the time-domain signal with an inverse Discrete Fourier Transform (IDFT) having the DFT size.

First claim

The invention claimed is:

1. A communication system comprising:
a communication apparatus including
a Discrete Fourier Transform (DFT) transformer which transforms a time-domain signal into a frequency-domain signal with a DFT size that is a product of powers of a plurality of values, the plurality of values being integer numbers that are greater than 1 and are different from each other, exponents for the plurality of values being a set of non-negative integers;
a mapper which maps the frequency-domain signal on a plurality of frequency bands, each frequency band being located at a position separate from position(s) of other(s) of the plurality of frequency bands, wherein a size of each of the plurality of frequency bands is a product of two or more powers of prime numbers or a multiple of the product of the two or more powers of prime numbers, each of the prime numbers being an integer number that is greater than 1 and the prime numbers being different from each other, exponents for the prime numbers being a set of non-negative integers; and
a signal generator which generates a single carrier-frequency division multiple access (SC-FDMA) time-domain signal from the mapped signal; and

a base station including
a receiver which receives the SC-FDMA time-domain signal;
a combiner which generates the frequency-domain signal from the SC-FDMA time-domain signal; and
a transformer which transforms the frequency-domain signal into the time-domain signal with an inverse Discrete Fourier Transform (IDFT) having the DFT size.

2. The communication system according to claim 1 , wherein a number of the plurality of frequency bands is two, and a size of one of the two frequency bands is a multiple of a product of two or more powers of prime numbers.

3. The communication system according to claim 1 , wherein the prime numbers are selected in order from a smaller prime number.

4. The communication system according to claim 1 , wherein a size of all of the plurality of frequency bands is a multiple of a product of two or more powers of prime numbers.

5. The communication system according to claim 1 , wherein a first exponent for a first prime number is equal to or greater than a second exponent for a second prime number that is greater than the first prime number.

6. The communication system according to claim 1 , wherein a size of each of the plurality of frequency bands is one minimum division unit or multiple minimum division units, wherein the minimum division unit is a minimum number of subcarriers that form each of the plurality of frequency bands and is a product of two or more powers of prime numbers.

7. The communication system according to claim 6 , wherein a size of all of the plurality of frequency bands is a multiple of the minimum division unit.

8. The communication system according to claim 7 , wherein the base station further comprises:
a transmitter which transmits allocation information indicating a frequency position of each of the plurality of frequency bands, the frequency position being indicated in terms of the minimum division unit.

9. The communication system according to claim 1 , wherein the base station further comprises:
a transmitter which transmits allocation information including the size of at least one of the plurality of frequency bands.

Assignees

• Sun Patent Trust

Inventors

• Takaoka Shinsuke
• Hoshino Masayuki
• Miyoshi Kenichi

Classifications

• H04L27/2602 Primary

  Signal structure · CPC title

• H04W72/0453 Primary

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

• H04L27/2636

  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

• G06F17/141

  Discrete Fourier transforms · CPC title