Communication apparatus and method for discrete fourier transforming a time domain symbol to a frequency domain signal

• US 10,178,674 B2
• Filed: 06/19/2018
• Issued: 01/08/2019
• Est. Priority Date: 09/22/2008
• Status: Active Grant

• Current Assignee: Sun Patent Trust
• Original Assignee: Sun Patent Trust
• Inventors: Takaoka, Shinsuke, Hoshino, Masayuki, Miyoshi, Kenichi
• Primary Examiner(s): Ghowrwal, Omar J
• Application Number:
  US16/012,519
• Publication Number:
  US 20180317229A1
• Time in Patent Office: 203 Days
• CPC Class Codes: G06F 17/141 Discrete Fourier transforms
• CPC Class Codes: H04J 1/00 Frequency-division multiplex systems H04J14/00 takes precedence
• CPC Class Codes: H04J 11/00 Orthogonal multiplex systems, e.g. using WALSH codesH04J13/00 takes precedence
• CPC Class Codes: H04J 4/005 Transmultiplexing
• CPC Class Codes: H04L 27/26 Systems using multi-frequency codes H04L27/32 takes precedence
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2636 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 Class Codes: H04L 5/0041 Frequency-non-contiguous
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y10S 370/916 Multiplexer/demultiplexer

Abstract

A communication apparatus includes a Discrete Fourier Transform (DFT) transformer, a mapper, and a signal generator. The DFT transformer transforms a symbol in a time domain into a signal in a frequency domain with a DFT size that is a product of powers of a plurality of values, which are integer numbers greater than 1 and are different from each other. The mapper maps the signal in the frequency domain on a plurality of frequency bands, wherein a vector length corresponding to 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 such product, and wherein the vector length is a number of subcarriers allocated to a corresponding one of the plurality of frequency bands. The signal generator generates a single carrier-frequency division multiple access (SC-FDMA) signal in the time domain from the mapped signal.

Claims

1. A communication apparatus comprising:

a Discrete Fourier Transform (DFT) transformer which transforms a symbol in a time domain into a signal in a frequency domain 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 signal in the frequency domain 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 vector length corresponding to 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 wherein the vector length is a number of subcarriers allocated to a corresponding one of the plurality of frequency bands; and

a signal generator which generates a single carrier-frequency division multiple access (SC-FDMA) signal in the time domain from the mapped signal.

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

4. The communication apparatus 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 apparatus 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 apparatus 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 to form each of the plurality of frequency bands and is a product of two or more powers of prime numbers.

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

8. A communication method performed by a communication apparatus, comprising:

transforming a symbol in a time domain into a signal in a frequency domain with a discrete Fourier transform (DFT) having a 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;

mapping the signal in the frequency domain 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 vector length corresponding to 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 wherein the vector length is a number of subcarriers allocated to a corresponding one of the plurality of frequency bands; and

generating a single carrier-frequency division multiple access (SC-FDMA) signal in the time domain from the mapped signal.

9. The communication method according to claim 8, 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.

10. The communication method according to claim 8, wherein the prime numbers are selected in order from a smaller prime number.

11. The communication method according to claim 8, 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.

12. The communication method according to claim 8, 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.

13. The communication method according to claim 8, wherein

a size of each of the plurality of frequency bands is one minimum division unit or multiple minimum division units, and wherein the minimum division unit is a minimum number of subcarriers to form each of the plurality of frequency bands and is a product of two or more powers of prime numbers.

14. The communication method according to claim 13, wherein a size of all of the plurality of frequency bands is a multiple of the minimum division unit.