Receiver and wireless communication system equipped with the same

• US 8,340,223 B2
• Filed: 09/19/2008
• Issued: 12/25/2012
• Est. Priority Date: 10/05/2007
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Tanaka, Akio
• Primary Examiner(s): Flores, Leon
• Application Number:
  US12/681,190
• Publication Number:
  US 20100226450A1
• Time in Patent Office: 1,558 Days
• Field of Search: 375/260, 375/316, 375/317, 375/324, 375/340, 455/130, 327/1, 327/37, 327/307, 327/336, 370/344, 370/480
• US Class Current: 375/316
• CPC Class Codes: H04B 1/71637 Receiver aspects H04B1/7183 takes precedence
• CPC Class Codes: H04L 25/06 Dc level restoring means; Bias distortion correction ; Decision circuits providing symbol by symbol detection

Abstract

A receiver includes: an amplifier that amplifies a received broadband signal up to a predetermined level; a first switch that switches an output signal from the amplifier; a signal generator that generates a signal for controlling a switching operation of the first switch; an integration capacitor that integrates an output signal from the first switch; a comparator that compares an output voltage from the integration capacitor with a predetermined voltage; and a reset circuit that discharges electrical charges accumulated in the integration capacitor based on a comparison result from the comparator.

Claims

1. A receiver comprising:

an amplifier that amplifies a received broadband signal up to a predetermined level;

a first switch that switches an output signal from the amplifier;

a signal generator that generates a signal for controlling a switching operation of the first switch;

an integration capacitor that integrates an output signal from the first switch;

a comparator that compares an output voltage from the integration capacitor with a predetermined voltage; and

a reset circuit that discharges electrical charges accumulated in the integration capacitor based on a comparison result from the comparator.

2. The receiver according to claim 1, wherein the broadband signal is a pulse radio frequency signal.

3. The receiver according to claim 2, further comprising:

a voltage supply that supplies the comparator with a first comparison voltage for detecting a positive correlation with the broadband signal and a second comparison voltage for detecting a negative correlation with the broadband signal; and

a controller that controls the voltage supply so that values of the first comparison voltage and the second comparison voltage become narrower in stages.

4. The receiver according to claim 2, further comprising:

a voltage supply that supplies the comparator with a first comparison voltage for detecting a positive correlation with the broadband signal and a second comparison voltage for detecting a negative correlation with the broadband signal; and

a controller that controls the voltage supply so that values of the first comparison voltage and the second comparison voltage vary according to a binary search method.

5. The receiver according to claim 2, wherein the comparator includes

a plurality of comparator elements that compare an output voltage of the integration capacitor with a comparison voltage that is a preset predetermined voltage, and

a receiver that further comprises a voltage supply that supplies comparison voltages that are respectively different from each other to the plurality of comparator elements.

6. The receiver according to claim 2, wherein the amplifier includes an inductor to be connected between a power supply potential and an output terminal.

7. The receiver according to claim 2, wherein the amplifier includes a cascode-structure transistor to be connected between a ground potential and an output terminal.

8. A wireless communication system comprising:

a transmitter for transmitting a broadband signal; and

the receiver according to claim 2 which receives the broadband signal.

9. The receiver according to claim 1, further comprising:

a voltage supply that supplies the comparator with a first comparison voltage for detecting a positive correlation with the broadband signal and a second comparison voltage for detecting a negative correlation with the broadband signal; and

a controller that controls the voltage supply so that values of the first comparison voltage and the second comparison voltage vary according to a binary search method.

10. The receiver according to claim 1, wherein the comparator includes

a plurality of comparator elements that compare an output voltage of the integration capacitor with a comparison voltage that is a preset predetermined voltage, and

a receiver that further comprises a voltage supply that supplies comparison voltages that are respectively different from each other to the plurality of comparator elements.

11. The receiver according to claim 1, wherein the amplifier includes an inductor to be connected between a power supply potential and an output terminal.

12. The receiver according to claim 1, wherein the amplifier includes a cascode-structure transistor to be connected between a ground potential and an output terminal.

13. The receiver according to claim 1, wherein:

the broadband signal is an MB-OFDM signal;

the receiver further comprising

a second switch that supplies the reset circuit with a reset signal for discharging electrical charges accumulated in the integration capacitor at predetermined time intervals generated by the signal generator; and

a controller that controls switching operations of the second switch.

14. A wireless communication system comprising:

a transmitter for transmitting a broadband signal; and

the receiver according to claim 1 which receives the broadband signal.

15. A receiver comprising:

an amplifier that amplifies a received broadband signal up to a predetermined level;

a first switch that switches an output signal from the amplifier;

a signal generator that generates a signal for controlling a switching operation of the first switch;

an integration capacitor that integrates an output signal from the first switch;

a comparator that compares an output voltage from the integration capacitor with a predetermined voltage;

a reset circuit that discharges electrical charges accumulated in the integration capacitor based on a comparison result from the comparator;

a voltage supply that supplies the comparator with a first comparison voltage for detecting a positive correlation with the broadband signal and a second comparison voltage for detecting a negative correlation with the broadband signal; and

a controller that controls the voltage supply so that values of the first comparison voltage and the second comparison voltage become narrower in stages.

16. A wireless communication system comprising:

a transmitter for transmitting a broadband signal; and

the receiver according to claim 15 which receives the broadband signal.

17. A reception method comprising:

amplifying a received broadband signal up to a predetermined level;

switching the amplified signal at a predetermined frequency using a switching element;

directly integrating the switched signal using an integration capacitor;

comparing the integrated voltage with a predetermined voltage using a comparator; and

resetting a voltage corresponding to electrical charges accumulated by the integration operation based on the comparison result.

18. The method according to claim 17, further comprising switching between demodulation of a pulse radio frequency signal that is the broadband signal and demodulation of an MB-OFDM signal that is the broadband signal.

19. The method according to claim 18, further comprising receiving pulse radio frequency signals at predetermined time intervals even when participating in an MB-OFDM beacon group.

20. The method according to claim 18, further comprising receiving MB-OFDM signals at predetermined time intervals even when an MB-OFDM signal beacon group is not being detected.