Frequency-division multiplexing transceiver apparatus and method

• US 20070189415A1
• Filed: 06/29/2006
• Published: 08/16/2007
• Est. Priority Date: 02/15/2006
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Kawasaki, Toshio
• Granted Patent: US 7,630,454 B2
• Time in Patent Office: Days
• US Class Current: 375/295
• CPC Class Codes: H04B 1/692 Hybrid techniques using combinations of two or more spread spectrum techniques
• CPC Class Codes: H04B 1/7097 Interference-related aspects
• CPC Class Codes: H04B 2201/70706 with means for reducing the peak-to-average power ratio

Abstract

In a frequency-division multiplexing transmission apparatus for transmitting data in a frequency spectrum specific to a mobile station, a chip-dividing unit divides each symbol of a transmission-symbol sequence into chips; a first phase rotation unit performs π/2 phase rotation for the odd-numbered chips of the divided chips; a chip-repetition and rearrangement unit compresses the time domains of each chip of the chip sequence after phase rotation, then repeats the chips a specified number of times and rearranges the chips of the obtained repetitive-chip sequences so that they have the same arrangement as the original chip sequence; a second phase rotation unit performs phase rotation that changes at a speed specific to a mobile station for each chip of the rearranged repetitive-chip sequence; and a transmission unit transmits said phase-rotated chips.

Claims

1. A frequency-division multiplexing transmission apparatus for transmitting data in a frequency spectrum specific to a mobile station, comprising:

a chip-dividing unit that divides each symbol of a transmission-symbol sequence into chips;

a first phase rotation unit that performs π

/2 or −

π

/2 phase rotation for the even-numbered or odd-numbered chips of said divided chips;

a chip-repetition and rearrangement unit that compresses the time domains of each chip of the chip sequence after phase rotation, then repeats the chips a specified number of times and rearranges the chips of the obtained repetitive-chip sequences so that they have the same arrangement as the original chip sequence;

a second phase rotation unit that performs phase rotation that changes at a speed specific to a mobile station for each chip of the rearranged repetitive-chip sequence; and

a transmission unit that transmits said phase-rotated chips.

2. A frequency-division multiplexing transmission apparatus for transmitting data in a frequency spectrum specific to a mobile station, comprising:

a chip-dividing unit that divides each symbol of a transmission-symbol sequence into chips;

a first phase rotation unit that performs π

/2 or −

π

/2 phase rotation for the even-numbered or odd-numbered chips of said divided chips;

a chip-repetition and rearrangement unit that compresses the time domains of each chip of the chip sequence after phase rotation, then repeats the chips a specified number of times (CRF times) and rearranges the chips of the obtained repetitive-chip sequences so that they have the same arrangement as the original chip sequence;

a second phase rotation unit that performs phase rotation that changes at a speed specific to a mobile station for each chip of the rearranged repetitive-chip sequence; and

a transmission unit that transmits said phase-rotated chips;

wherein said second phase rotation unit changes the amount of phase rotation performed for each chip of said repetitive-chip sequence in increments of k·

2π

/CRF (k is an integer specific to a mobile station) at each period of the repetitive-chip sequence.

3. The frequency-division multiplexing transmission apparatus according to claim 2 wherein

said second phase rotation unit comprises:

a rotation-phase-generation unit that generates phase that increases in increments of k·

2π

/CRF at each period of said repetitive-chip sequence; and

a complex multiplier that performs phase rotation that corresponds to the generated phase for each chip of said repetitive-chip sequence.

4. A frequency-division multiplexing receiving apparatus according to claim 2 comprising:

a receiving unit that receives each of the chips of said repetitive-chip sequence that are transmitted from said transmission apparatus;

a phase rotation unit that performs phase rotation for the received chips that changes in increments of k·

2π

/CRF (k is an integer specific to a mobile station) at each period of said repetitive-chip sequence for each mobile station; and

a demodulation unit that performs −

π

/2 or π

/2 phase rotation for the even-numbered or odd-numbered chips of each chip sequence consisted of the same chip components that are output from said rotation unit and synthesizes the phase-rotated chips for each chip sequence to demodulate the transmission symbols.

5. A frequency-division multiplexing transmission apparatus for transmitting data in a frequency spectrum specific to a mobile station, comprising:

a symbol-repetition and rearrangement unit that compresses the time domains of each symbol of a transmission-symbol sequence, then repeats each of the symbols a specified number of times and rearranges each of the symbols of the obtained repetitive-symbol sequence so that they have the same arrangement as the transmission-symbol sequence;

a chip-dividing unit that divides the rearranged repetitive symbols into chips;

a first phase rotation unit that performs π

/2 or −

π

/2 phase rotation for the even-numbered or odd-numbered chips of the divided chip sequence;

a second phase rotation unit that performs phase rotation that changes at a speed specific to a mobile station for each chip of the phase-rotated chip sequence; and

a transmission unit that transmits said phase-rotated chips.

6. A frequency-division multiplexing transmission apparatus for transmitting data in a frequency spectrum specific to a mobile station, comprising:

a symbol-repetition and rearrangement unit that compresses the time domains of each symbol of a transmission-symbol sequence, then repeats each of the symbols a specified number of times (CRF times) and rearranges each of the symbols of the obtained repetitive-symbol sequence so that they have the same arrangement as the transmission-symbol sequence;

a chip-dividing unit that divides the rearranged repetitive symbols into chips;

a first phase rotation unit that performs π

/2 or −

π

/2 phase rotation for the even-numbered or odd-numbered chips of the divided chip sequence;

a second phase rotation unit that performs phase rotation that changes at a speed specific to a mobile station for each chip of the phase-rotated chip sequence; and

a transmission unit that transmits said phase-rotated chips;

wherein

said second phase rotation unit changes the amount of phase rotation performed for each chip of said repetitive-chip sequence in increments of k·

2π

/CRF (k is an integer specific to a mobile station) at each period of the repetitive-chip sequence.

7. The frequency-division multiplexing transmission apparatus according to claim 6 wherein

said second phase rotation unit comprises:

a rotation-phase-generation unit that generates phase that increases in increments of k·

2π

/CRF at each period of said repetitive-chip sequence; and

a complex multiplier that performs phase rotation that corresponds to the generated phase for each chip of said repetitive-chip sequence.

8. A frequency-division multiplexing receiving apparatus according to claim 6 comprising:

a receiving unit that receives each of the chips of said repetitive-chip sequence that are transmitted from said transmission apparatus;

a first phase rotation unit that performs phase rotation for the received chips that changes in increments of k·

2π

/CRF (k is an integer specific to a mobile station) at each period of said repetitive-chip sequence for each mobile station;

a second phase rotation unit that performs −

π

/2 or π

/2 phase rotation for the even-numbered or odd-numbered chips of said repetitive-chip sequence; and

a demodulation unit that synthesizes the same chip components that are output from said second phase rotation unit to demodulate the transmission symbols.

9. A frequency-division multiplexing transmission apparatus for transmitting data in a frequency spectrum specific to a mobile station, comprising:

a spreading-code-generation unit that generates a repeating spreading code in which the phase difference between adjacent spreading code alternates between ±

π

/2 and m·

π

/2 (m is an integer);

a spreading unit that multiplies each symbol of a transmission-symbol sequence by the spreading code;

a chip-repetition and rearrangement unit that compresses the time domains of each chip of a chip sequence obtained from said multiplication, then repeats the chips a specified number of times (CRF times) and rearranges the chips of the obtained repetitive-chip sequences so that they have the same arrangement as the original chip sequence;

a phase rotation unit that performs phase rotation that changes at a speed specific to a mobile station for each chip of the rearranged repetitive-chip sequence; and

a transmission unit that transmits said phase-rotated chips;

wherein

said phase rotation unit changes the amount of phase rotation performed for each chip of said repetitive-chip sequence in increments of k·

2π

/CRF (k is an integer specific to a mobile station) at each period of the repetitive-chip sequence.

10. The frequency-division multiplexing transmission apparatus according to claim 9 wherein

said phase rotation unit comprises:

a rotation-phase-generation unit that generates phase that increases in increments of k·

2π

/CRF at each period of said repetitive-chip sequence; and

a complex multiplier that performs phase rotation that corresponds to the generated phase for each chip of said repetitive-chip sequence.

11. A frequency-division multiplexing receiving apparatus according to claim 9 comprising:

a receiving unit that receives each of the chips of said repetitive-chip sequence that are transmitted from said transmission apparatus;

a phase rotation unit that performs phase rotation for the received chips that changes in increments of k·

2π

/CRF (k is an integer specific to a mobile station) at each period of said repetitive-chip sequence for each mobile station;

a spreading-code-generation unit that generates spreading code that is the same as the spreading code of said transmission apparatus;

a reverse-spreading unit that performs a reverse spreading process using the phase-rotated chip sequence and said generated spreading code; and

a demodulation unit that synthesizes the same symbol components of the chip sequence after reverse spreading to demodulate the transmission symbols.

12. A frequency-division multiplexing transmission method of transmitting data in a frequency spectrum specific to a mobile station, comprising:

a first step of dividing each symbol of a transmission-symbol sequence into chips;

a second step of performing π

/2 or −

π

/2 phase rotation for the even-numbered or odd-numbered chips of said divided chips;

a third step of compressing the time domains of each chip of the chip sequence after phase rotation, then repeating the chips a specified number of times (CRF times) and rearranging the chips of the obtained repetitive-chip sequence so that they have the same arrangement as the original chip sequence;

a fourth step of performing phase rotation that changes at a speed specific to a mobile station for each chip of the rearranged repetitive-chip sequence; and

a fifth step of transmitting said phase-rotated chips;

wherein

the amount of phase rotation performed for each chip of said repetitive-chip sequence changes in increments of k·

2π

/CRF (k is an integer specific to a mobile station) at each period of the repetitive-chip sequence.

13. The frequency-division multiplexing transmission method according to claim 12 wherein

said fourth step comprised steps of:

generating phase that increases in increments of k·

2π

/CRF at each period of said repetitive-chip sequence; and

performing phase rotation that corresponds to the generated phase for each chip of said repetitive-chip sequence.

14. A frequency-division multiplexing receiving method according to claim 12 comprising:

a step of receiving each of the chips of said repetitive-chip sequence that are transmitted from said transmission apparatus;

a step of performing phase rotation for the received chips that changes in increments of k·

2π

/CRF (k is an integer specific to a mobile station) at each period of said repetitive-chip sequence for each mobile station; and

a step of performing −

π

/2 or π

/2 phase rotation for the even-numbered or odd-numbered chips of each chip sequence consisted of the same chip components that are output from the rotation unit and synthesizing the phase-rotated chips for each chip sequence to demodulate the transmission symbols.

15. A frequency-division multiplexing transmission method of transmitting data in a frequency spectrum specific to a mobile station, comprising:

a first step of compressing the time domains of each symbol of a transmission-symbol sequence, then repeating each of the symbols a specified number of times (CRF times) and rearranging each of the symbols of the obtained repetitive-symbol sequence so that they have the same arrangement as the transmission-symbol sequence;

a second step of dividing the rearranged repetitive symbols into chips;

a third step of performing π

/2 or −

π

/2 phase rotation for the even-numbered or odd-numbered chips of the divided chip sequence;

a fourth step of performing phase rotation that changes at a speed specific to a mobile station for each chip of the phase-rotated chip sequence; and

a fifth step of transmitting said phase-rotated chips;

wherein

the amount of phase rotation performed for each chip of said repetitive-chip sequence changes in increments of k·

2π

/CRF (k is an integer specific to a mobile station) at each period of the repetitive-chip sequence.

16. The frequency-division multiplexing transmission method according to claim 15 wherein

said fourth step comprises steps of:

generating phase that increases in increments of k·

2π

/CRF at each period of said repetitive-chip sequence; and

performing phase rotation that corresponds to the generated phase for each chip of said repetitive-chip sequence.

17. A frequency-division multiplexing receiving method according to claim 15 comprising:

a first step of receiving each of the chips of said repetitive-chip sequence that are transmitted from said transmission apparatus;

a second step of performing phase rotation for the received chips that changes in increments of k·

2π

/CRF (k is an integer specific to a mobile station) at each period of said repetitive-chip sequence for each mobile station;

a third step of performing −

π

/2 or π

/2 phase rotation for the even-numbered or odd-numbered chips of said repetitive-chip sequence; and

a fourth step of synthesizing the same chip components of the chip sequence whose phase was rotated in the third step to demodulate the transmission symbols.

18. A frequency-division multiplexing transmission method of transmitting data in a frequency spectrum specific to a mobile station, comprising:

a first step of generating a repeating spreading code in which the phase difference between adjacent spreading code alternates between ±

π

/2 and m·

π

/2 (m is an integer);

a second step of multiplying each symbol of a transmission-symbol sequence by the spreading code;

a third step of compressing the time domains of each chip of a chip sequence obtained from said multiplication, then repeating the chips a specified number of times (CRF times) and rearranging the chips of the obtained repetitive-chip sequences so that they have the same arrangement as the original chip sequence;

a fourth step of performing phase rotation that changes at a speed specific to a mobile station for each chip of the rearranged repetitive-chip sequence; and

a fifth step of transmitting said phase-rotated chips;

wherein

the amount of phase rotation performed for each chip of said repetitive-chip sequence changes in increments of k·

2π

/CRF (k is an integer specific to a mobile station) at each period of the repetitive-chip sequence.

19. The frequency-division multiplexing transmission method according to claim 18 wherein

said fourth step comprised steps of:

generating phase that increases in increments of k·

2π

/CRF at each period of said repetitive-chip sequence; and

performing phase rotation that corresponds to the generated phase for each chip of said repetitive-chip sequence.

20. A frequency-division multiplexing receiving method according to claim 18 comprising:

a step of receiving each of the chips of said repetitive-chip sequence that are transmitted from said transmission apparatus;

a step of performing phase rotation for the received chips that changes in increments of k·

2π

/CRF (k is an integer specific to a mobile station) at each period of said repetitive-chip sequence for each mobile station;

a step of generating spreading code that is the same as the spreading code of said transmission apparatus, and performing a reverse spreading process using said phase-rotated chip sequence and said generated spreading code; and

a step of synthesizing the same symbol components of the chip sequence after reverse spreading to demodulate the transmission symbols.