Communication apparatus and a communication method for combining signals mapped on a plurality of frequency bands and transforming the combined signal into a symbol in a time domain

• US 9,042,213 B2
• Filed: 11/05/2013
• Issued: 05/26/2015
• Est. Priority Date: 09/22/2008
• Status: Active Grant

• Current Assignee: Sun Patent Trust
• Original Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Inventors: Takaoka, Shinsuke, Hoshino, Masayuki, Miyoshi, Kenichi
• Primary Examiner(s): GHOWRWAL, OMAR J
• Application Number:
  US14/072,668
• Publication Number:
  US 20140064241A1
• Time in Patent Office: 567 Days
• Field of Search: None
• US Class Current: 370/210
• 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

Provided is a radio communication device which can reduce ISI caused by destruction of an orthogonal DFT matrix even when an SC-FDMA signal is divided into a plurality of clusters and the clusters are respectively mapped to discontinuous frequency bands. The radio communication device includes a DFT unit (110), a division unit (111), and a mapping unit (112). The DFT unit (110) uses the DFT matrix to execute a DFT process on a symbol sequence in a time region to generate a signal (SC-FDMA signal) of the frequency region. The division unit (111) generates a plurality of clusters by dividing the SC-FDMA signal with a partially orthogonal bandwidth corresponding to the vector length of some of the column vectors constituting the DFT matrix used in the DFT unit (110) and orthogonally intersecting at least partially. The mapping unit (112) maps the clusters to discontinuous frequency bands.

Claims

1. A communication apparatus comprising:

a combining section configured to combine signals mapped on a plurality of frequency bands in a frequency domain into a combined signal, each frequency band including a plurality of subcarriers, each frequency band being located at a position separate from position(s) of other of the plurality of frequency bands, and a size of at least one of the plurality of frequency bands being a multiple of a product of two or more powers of prime numbers, the prime numbers being integer numbers that are greater than 1 and are different from each other, exponents for the prime numbers being a set of non-negative integers; and

a transforming section configured to transform the combined signal in the frequency domain into a symbol in a time domain with an inverse discrete Fourier transform (IDFT) 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.

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 prima 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 1 minimum division unit or multiple minimum division units, and the minimum division unit being a product of two or more powers of prime numbers, and 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.

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. The communication apparatus according to claim 7, further comprising:

a transmitter configured to transmit 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 apparatus according to claim 1, further comprising:

a transmitter configured to transmit allocation information including the size of at least one of the plurality of frequency bands.

10. A communication method performed by a communication apparatus comprising:

a combining section combining signals mapped on a plurality of frequency bands in a frequency domain into a combined signal, each frequency band including a plurality of subcarriers, each frequency band being located at a position separate from position(s) of other of the plurality of frequency bands, and a size of at least one of the plurality of frequency bands being a multiple of a product of two or more powers of prime numbers, the prime numbers being integer numbers that are greater than 1 and are different from each other, exponents for the prime numbers being a set of non-negative integers; and

a transforming section transforming the combined signal in the frequency domain into a symbol in a time domain with an inverse discrete Fourier transform (IDFT) 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.

11. The communication method according to claim 10, 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.

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

13. The communication method according to claim 10, 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.

14. The communication method according to claim 10, 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.

15. The communication method according to claim 10, wherein a size of each of the plurality of frequency bands is 1 minimum division unit or multiple minimum division units, and the minimum division unit being a product of two or more powers of prime numbers, and 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.

16. The communication method according to claim 15, wherein a size of all of the plurality of frequency bands is a multiple of the minimum division unit.

17. The communication method according to claim 16, further comprising:

transmitting 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.

18. The communication method according to claim 10, further comprising:

transmitting allocation information including the size of at least one of the plurality of frequency bands.