Frequency-division multiplexing transceiver apparatus and method

• US 20070189414A1
• Filed: 06/15/2006
• 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 7,599,428 B2
• Time in Patent Office: Days
• US Class Current: 375/295
• CPC Class Codes: H04L 27/2621 Reduction thereof using phase offsets between subcarriers
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601

Abstract

A frequency-division multiplexing transmission apparatus that transmits data at a frequency spectrum specific to a mobile station in which a π/4-continuous-phase-rotation unit performs phase rotation that increases in increments of π/4 or decreases in decrements of −π/4 for each symbol of a transmission-symbol sequence; a symbol-repetition and rearrangement unit compresses the time domains of each symbol of the transmission-symbol sequence after phase rotation, then repeats those symbols a specified number of times (L times), and rearranges the symbols of the obtained repetitive-symbol sequence so that it has the same arrangement as the original transmission-symbol sequence; a phase-rotation unit performs phase rotation that changes at a speed specific to the mobile station for each symbol of the rearranged repetitive-symbol sequence; and a transmission unit transmits the phase-rotated symbols.

Claims

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

a first phase-rotation unit that performs phase rotation that increases in increments of π

/4 or decreases in decrements of −

π

/4 for each symbol of a transmission-symbol sequence;

a symbol-repetition and rearrangement unit that compresses the time domains of each symbol of the transmission-symbol sequence after phase rotation, then repeats those symbols a specified number of times (L times), and rearranges the symbols of the obtained repetitive-symbol sequence so that it has the same arrangement as the transmission-symbol sequence;

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

a transmission unit that transmits said phase-rotated symbols.

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

a first phase-rotation unit that performs phase rotation that increases in increments of π

/4 or decreases in decrements of −

π

/4 for each symbol of a transmission-symbol sequence;

a symbol-repetition and rearrangement unit that compresses the time domains of each symbol of the transmission-symbol sequence after phase rotation, then repeats those symbols a specified number of times (L times), and rearranges the symbols of the obtained repetitive-symbol sequence so that it has the same arrangement as the transmission-symbol sequence;

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

a transmission unit that transmits said phase-rotated symbols;

wherein

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

2π

/L (where k is an integer specific to the mobile station) at each period of said repetitive-symbol sequence.

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

said second phase-rotation unit comprises:

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

2π

/L at each period of said repetitive-symbol sequence; and

a complex multiplier that performs the generated phase rotation on each symbol of said repetitive-symbol sequence.

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

a receiving unit that receives each symbol of a repetitive-symbol sequence that is transmitted from said transmission apparatus;

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

2π

/L (where k is an integer specific to the mobile station) at each period of said repetitive-symbol sequence for each mobile station, and performs phase rotation having that phase for each received symbol of the repetitive-symbol sequence; and

a demodulation unit that combines components of identical symbols that are output from said phase-rotation unit, and performs phase rotation that decreases in decrements of −

π

/4 or increases in increments of π

/4 for each symbol of the combined symbol 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 first phase-rotation unit that performs π

/4 or −

π

/4 phase rotation for the even-numbered or odd-numbered symbols of a transmission-symbol sequence;

a symbol-repetition and rearrangement unit that compresses the time domains of each symbol of the transmission-symbol sequence after phase rotation, then repeats those symbols a specified number of times (L times), and rearranges the symbols of the obtained repetitive-symbol sequence so that it has the same arrangement as the transmission-symbol sequence;

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

a transmission unit that transmits said phase-rotated symbols.

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

a first phase-rotation unit that performs π

/4 or −

π

/4 phase rotation for the even-numbered or odd-numbered symbols of a transmission-symbol sequence;

a symbol-repetition and rearrangement unit that compresses the time domains of each symbol of the transmission-symbol sequence after phase rotation, then repeats those symbols a specified number of times (L times), and rearranges the symbols of the obtained repetitive-symbol sequence so that it has the same arrangement as the transmission-symbol sequence;

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

a transmission unit that transmits said phase-rotated symbols;

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

2π

/L (where k is an integer specific to the mobile station) at each period of said repetitive-symbol sequence.

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

said second phase-rotation unit comprises:

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

2π

/L at each period of said repetitive-symbol sequence; and

a complex multiplier that performs the generated phase rotation on each symbol of said repetitive-symbol sequence.

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

a receiving unit for receiving each symbol of a repetitive-symbol sequence that is transmitted from said transmission apparatus;

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

2π

/L (where k is an integer specific to the mobile station) at each period of said repetitive-symbol sequence for each mobile station, and performs phase rotation having that phase for each received symbol of the repetitive-symbol sequence; and

a demodulation unit that combines components of identical symbols that are output from said phase-rotation unit, and performs −

π

/4 or π

/4 phase rotation for the even-numbered or odd-numbered symbols to demodulate the transmission symbols.

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

a first step of performing phase rotation that increases in increments of π

/4 or decreases in decrements of −

π

/4 for each symbol of a transmission-symbol sequence;

a second step of compressing the time domains of each symbol of the transmission-symbol sequence after phase rotation, then repeating those symbols a specified number of times (L times), and rearranging the symbols of the obtained repetitive-symbol sequence so that it has the same arrangement as the transmission-symbol sequence;

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

a fourth step of transmitting said phase-rotated symbols;

wherein

in said third step, the amount of rotation performed on each symbol of said repetitive-symbol sequence changes in increments of k·

2π

/L (where k is an integer specific to the mobile station) at each period of said repetitive-symbol sequence.

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

said third step comprises:

a step of generating phase that increases in increments of k·

2π

/L at each period of said repetitive-symbol sequence; and

a step of performing the generated phase rotation on each symbol of said repetitive-symbol sequence.

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

a fifth step of receiving each symbol of a repetitive-symbol sequence that is transmitted from said transmission apparatus;

a sixth step of generating phase that changes in increments of k−

2π

/L (where k is an integer specific to the mobile station) at each period of said repetitive-symbol sequence for each mobile station, and performing phase rotation having that phase for each received symbol of the repetitive-symbol sequence; and

a seventh step of combining components of identical symbols that are output from said phase-rotation unit, and performing phase rotation that decreases in decrements of −

π

/4 or increases in increments of π

/4 for each symbol of the combined symbol sequence to demodulate the transmission symbols.

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

a first step of performing π

/4 or −

π

/4 phase rotation for the even-numbered or odd-numbered symbols of a transmission-symbol sequence;

a second step of compressing the time domains of each symbol of the transmission-symbol sequence after phase rotation, then repeating those symbols a specified number of times (L times), and rearranging the symbols of the obtained repetitive-symbol sequence so that it has the same arrangement as the transmission-symbol sequence;

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

a fourth step of transmitting said phase-rotated symbols;

wherein

in said third step, the amount of rotation performed on each symbol of said repetitive-symbol sequence changes in increments of k·

2π

/L (where k is an integer specific to the mobile station) at each period of said repetitive-symbol sequence.

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

said third step comprises:

a step of generating phase that increases in increments of k·

2π

/L at each period of said repetitive-symbol sequence; and

a step of performing the generated phase rotation on each symbol of said repetitive-symbol sequence.

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

a fifth step receiving each symbol of a repetitive-symbol sequence that is transmitted from said transmission apparatus;

a sixth step of generating phase that changes in increments of k·

2π

/L (where k is an integer specific to the mobile station) at each period of said repetitive-symbol sequence for each mobile station, and performing phase rotation having that phase for each received symbol of the repetitive-symbol sequence; and

a seventh step of combining components of identical symbols that are output from said phase-rotation unit, and performing −

π

/4 or π

/4 phase rotation for even-numbered or odd-numbered symbols to demodulate the transmission symbols.