Radio receiver and radio receiving method

• US 20060256884A1
• Filed: 02/21/2006
• Published: 11/16/2006
• Est. Priority Date: 05/11/2005
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Tomioka, Tazuko, Yoshida, Hiroshi, Horiguchi, Tomoya, Nounin, Katsuya, Sakata, Ren
• Granted Patent: US 7,609,793 B2
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H04B 1/71637 Receiver aspects H04B1/7183 takes precedence
• CPC Class Codes: H04B 7/0857 using maximum ratio combining techniques, e.g. signal-to- interference ratio [SIR], received signal strenght indication [RSS]
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01

Abstract

According to an aspect of the present invention, there is provided with a radio receiver including: one or more antenna which receives radio signals; a plurality of filters which selectively output signals in respective reception bands from the radio signals received by the antenna, adjacent reception bands partially overlapping each other; a plurality of A/D converters disposed correspondingly to the filters to convert the signals output from the respective filters to digital signals; extracting units which extract signal components of a boundary radio signal spreading across at least two reception bands adjacent to each other from digital signals associated with the at least two reception bands adjacent to each other; a combining unit which combines the signal components extracted by the extracting units to restore the boundary radio signal; and a demodulation unit which demodulates the boundary radio signal restored by the combining unit.

Claims

1. A radio receiver comprising:

one or more antenna which receives radio signals;

a plurality of filters which selectively output signals in respective reception bands from the radio signals received by the antenna, adjacent reception bands partially overlapping each other;

a plurality of A/D converters disposed correspondingly to the filters to convert the signals output from the respective filters to digital signals;

extracting units which extract signal components of a boundary radio signal spreading across at least two reception bands adjacent to each other from digital signals associated with the at least two reception bands adjacent to each other;

a combining unit which combines the signal components extracted by the extracting units to restore the boundary radio signal; and

a demodulation unit which demodulates the boundary radio signal restored by the combining unit.

2. The radio receiver according to claim 1, comprising at least two low noise amplifiers which amplify the radio signals received by the one or more antenna,

wherein two or more filters which conduct processing on the at least two reception bands adjacent to each other is connected respectively to different low noise amplifiers.

3. The radio receiver according to claim 2, comprising at least two antennas,

wherein the low noise amplifiers are connected respectively to different antennas.

4. The radio receiver according to claim 2, wherein the combining unit conducts the combining by using maximum ratio combining method.

5. The radio receiver according to claim 3, wherein the combining unit conducts the combining by using maximum ratio combining method.

6. The radio receiver according to claim 1, further comprising a plurality of down converters disposed correspondingly to the filters to conduct down-conversion from radio frequency to intermediate frequency on signals output from respective filters,

wherein

the A/D converters conduct A/D conversion on signals of intermediate frequency output from respective down converters, and

as regards down converters and A/D converters which conduct processing on the at least two reception bands adjacent to each other, a ratio of a down conversion frequency difference between the down converters to a sampling frequency used in the A/D converters is definite.

7. The radio receiver according to claim 6, comprising:

a frequency synthesizer;

a sampling clock generation unit which generates sampling clocks to be supplied to the A/D converters, by using the frequency synthesizer output; and

a local signal generation unit which generates local signals for the down converters, by using the frequency synthesizer output.

8. The radio receiver according to claim 1, wherein the combining unit provides one or more subject signal component of the signal components extracted by the extracting uints with a time shift equivalent to a previously given delay difference and conducts the combining.

9. The radio receiver according to claim 1, further comprising a delay difference detection unit which compares waveforms of the signal components extracted by the extracting units to detect a delay difference,

wherein the combining unit provides one or more subject signal component of the extracted signal components with a time shift equivalent to the delay difference detected by the delay difference detection unit and conducts the combining.

10. The radio receiver according to claim 1, further comprising:

a plurality of FFT units disposed correspondingly to the A/D converters to conduct fast Fourier transform on digital signals generated by respective A/D converters; and

an IFFT unit which conducts inverse fast Fourier transform on the boundary radio signal restored by the combining unit.

11. The radio receiver according to claim 10, further comprising a plurality of down converters disposed correspondingly to the filters to conduct down-conversion from radio frequency to intermediate frequency on signals output from respective filters,

wherein

the A/D converters conduct A/D conversion on signals of intermediate frequency output from respective down converters, and

as regards down converters and FFT units which conduct processing on the at least two reception bands adjacent to each other, a ratio of a down conversion frequency difference between the down converters to a reciprocal of a frame length used in the FFT units is definite.

12. The radio receiver according to claim 11, comprising:

a frequency synthesizer;

a sampling clock generation unit which generates sampling clocks to be supplied to the A/D converters, by using the frequency synthesizer output; and

a local signal generation unit which generates local signals for the down converters, by using the frequency synthesizer output.

13. The radio receiver according to claim 10, further comprising a timing supply unit which supplies a timing signal indicating a timing of framing to each of FFT units that conduct processing on the signals of at least two reception bands adjacent to each other, on the basis of a previously given delay difference of digital signals input to the FFT units.

14. The radio receiver according to claim 11, further comprising a timing supply unit which supplies a timing signal indicating a timing of framing to each of the FFT units that conduct processing on the signals of at least two reception bands adjacent to each other, on the basis of a previously given delay difference of digital signals input to the FFT units.

15. The radio receiver according to claim 1, further comprising:

a plurality of FFT units disposed correspondingly to the A/D converters to conduct fast Fourier transform on digital signals generated by respective A/D converters; and

IFFT units which conduct inverse fast Fourier transform on the signal components extracted by the extracting units,

wherein the combining unit conducts the combining on signals obtained after inverse fast Fourier transform.

16. A radio receiving method comprising:

receiving radio signals at one or more antenna;

selectively outputting signals included in each of a plurality of preset reception bands from the received radio signals, adjacent reception bands partially overlapping each other;

conducting A/D conversion on the output signals to generate digital signals;

extracting signal components of a boundary radio signal spreading across at least two reception bands adjacent to each other from digital signals associated with the at least two reception bands adjacent to each other;

combining the extracted signal components to restore the boundary radio signal; and

demodulating the restored boundary radio signal.