Transmitter, receiver, and method of data transmission

• US 20030016731A1
• Filed: 10/30/2001
• Published: 01/23/2003
• Est. Priority Date: 03/15/2000
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Uesugi, Mitsuru
• Granted Patent: US 7,012,949 B2
• Time in Patent Office: Days
• US Class Current: 375/130
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601
• CPC Class Codes: H04L 5/06 the signals being represented by different frequencies combined with time-division multiplexing H04L5/26

Abstract

A transmitting apparatus 100 spreads broadcast information by means of a spreading section 103, limits the band of spread broadcast information by means of a band limiting filter section 104 so as not to overlap a guard frequency band, adds the output signal of a band limiting filter section 104 to transmit data after an inverse Fourier transform by means of an adding section 105, modulates the resulting signal by means of a modulation section 106, and transmits it. A receiving apparatus 150 passes only a signal in a guard frequency band by means of a reception filter section 154, demodulates it by means of a demodulation section 155, despreads it by means of a despreading section 156, and performs rake reception by means of a rake reception section 157 to obtain broadcast information. By this means, guard frequency bands can be used efficiently, and spectrum efficiency can be improved.

Claims

1. A transmitting apparatus comprising:

inverse Fourier transform means for performing an inverse Fourier transform on transmit data converted to parallel form to obtain a first signal;

first filter means for limiting the band of a second signal so that it is not superimposed on a guard frequency band adjacent to the band of said first signal; and

transmitting means for transmitting the second signal for which the band is limited superimposed on said first signal.

2. The transmitting apparatus according to claim 1, further comprising spreading means for spreading the second signal, wherein the first filter means limits the band of the spread second signal.

3. The transmitting apparatus according to claim 1, further comprising first spectrum processing means for processing the spectrum of the second signal output from the first filter means so that it becomes greater the nearer it is to the band of the first signal.

4. The transmitting apparatus according to claim 1, further comprising shift means for shifting the bands of a plurality of second signals output from the first filter means so as not to overlap mutually within the range of a guard frequency band, wherein the transmitting means transmits a plurality of second signals output from said shift means superimposed on the first signal.

5. The transmitting apparatus according to claim 4, wherein the shift means comprises generating means for generating a third signal for suppressing the composite amplitude of the first signal, and shifts the bands of a plurality of second signals output from the first filter means and said third signal so as not to overlap mutually within the range of a guard frequency band.

6. The transmitting apparatus according to claim 5, wherein the shift means shifts the third signal so as to be placed in a part adjacent to the band of the first signal.

7. A receiving apparatus comprising second filter means for passing only signals in a guard frequency band among signals transmitted from the transmitting apparatus according to claim 1.

8. A receiving apparatus comprising:

second filter means for passing only signals in a guard frequency band among signals transmitted from the transmitting apparatus according to claim 2; and

despreading means for despreading a signal that has passed through this second filter means.

9. A receiving apparatus comprising:

second filter means for passing only signals in a guard frequency band among signals transmitted from the transmitting apparatus according to claim 3; and

second spectrum processing means for performing the opposite processing to that of first spectrum processing means on a signal that has passed through this second filter means.

10. A communication terminal apparatus equipped with a transmitting apparatus, said transmitting apparatus comprising:

inverse Fourier transform means for performing an inverse Fourier transform on transmit data converted to parallel form to obtain a first signal;

first filter means for limiting the band of a second signal so that it is not superimposed on a guard frequency band adjacent to the band of said first signal; and

transmitting means for transmitting the second signal for which the band is limited superimposed on said first signal.

13. A base station apparatus equipped with a receiving apparatus, wherein said receiving apparatus comprises second filter means for passing only signals in a guard frequency band among signals transmitted from the communication terminal apparatus according to claim 10.

11. A base station apparatus equipped with a transmitting apparatus, said transmitting apparatus comprising:

inverse Fourier transform means for performing an inverse Fourier transform on transmit data converted to parallel form to obtain a first signal;

first filter means for limiting the band of a second signal so that it is not superimposed on a guard frequency band adjacent to the band of said first signal; and

transmitting means for transmitting the second signal for which the band is limited superimposed on said first signal.

12. A communication terminal apparatus equipped with a receiving apparatus, said receiving apparatus comprising second filter means for passing only signals in a guard frequency band among signals transmitted from the base station apparatus according to claim 11.

15. The data transmission method according to claim 14, further comprising the steps of:

on the transmitting side, spectrum processing of the spectrum of the second signal output so that it becomes greater the nearer it is to the band of the first signal; and

on the receiving side, performing the opposite processing to that of the spectrum processing on the transmitting side.

16. The data transmission method according to claim 14, further comprising the step of, on the transmitting side, performing multicarrier transmission of the second signal.

14. A data transmission method comprising the steps of:

on the transmitting side, limiting the band of a second signal so that data converted to parallel form becomes a band adjacent to the band of a first signal that has undergone an inverse Fourier transform, and transmitting the second signal for which the band is limited superimposed on said first signal; and

on the receiving side, performing a Fourier transform on said first signal and extracting said data, and demodulating a guard frequency band signal and extracting said second signal.