Radio communication device and radio communication method

• US 8,824,975 B2
• Filed: 02/23/2011
• Issued: 09/02/2014
• Est. Priority Date: 03/02/2010
• Status: Expired due to Fees

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Sato, Junji, Fujita, Suguru
• Primary Examiner(s): Urban, Edward
• Assistant Examiner(s): Justus, Ralph H
• Application Number:
  US13/318,416
• Publication Number:
  US 20120052819A1
• Time in Patent Office: 1,287 Days
• Field of Search: 455/78, 455/80, 455/114.3, 455/126, 455/295, 455/501, 455/506, 455/63.1, 455/67.11, 455/67.13, 455/67.16, 455/115.1
• US Class Current: 455/78
• CPC Class Codes: H03F 1/3247 using feedback acting on predistortion circuits H03F1/3264 takes precedence
• CPC Class Codes: H03F 1/34 Negative-feedback-circuit arrangements with or without positive feedback H03F1/02 - H03F1/30, H03F1/38 - H03F1/50, H03F3/50 take precedence ; for rejection of common mode signals H03F3/45479
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H03F 3/245 with semiconductor devices only
• CPC Class Codes: H03F 3/604 using FET's
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 2001/0433 with linearisation using feedback

Abstract

It is provided a radio communication apparatus and radio communication method that, in the radio communication apparatus having a normal transmitting/receiving mode and a distortion correction mode, communicates successfully without influencing circuit characteristic in a normal transmitting/receiving mode, sends back a transmitting signal from the receiving system, extracts a distortion component due to narrowband characteristics or non-linear characteristics of a circuit, and corrects distortion in a distortion correction mode. In radio communication apparatus (100), distortion detecting section (111) extracts a distortion component using a transmitting baseband signal and a receiving baseband signal, coupling degree adjustment circuit (180) adjusts the degree of coupling between transmitting antenna (130) and receiving antenna (140), and coupling degree control section (170) switches the degree of coupling depending on a normal transmitting/receiving mode or a distortion correction mode.

Claims

1. A radio communication apparatus that has a normal transmitting/receiving mode and a distortion correction mode, the apparatus comprising:

a transmitting circuit that includes a transmitting processing circuit configured to generate a high frequency signal from a transmitting baseband signal by radio transmitting process and a power amplifier configured to amplify the high frequency signal;

a transmitting antenna configured to transmit the high frequency signal amplified by the power amplifier;

a receiving antenna configured to receive the high frequency signal transmitted by the transmitting antenna;

a receiving circuit that includes a low noise amplifier configured to amplify the high frequency signal received by the receiving antenna and a receiving processing circuit configured to generate a receiving baseband signal by demodulating the high frequency signal amplified by the low noise amplifier;

a distortion detecting section configured to detect a distortion component using the transmitting baseband signal and the receiving baseband signal;

an adjustment section arranged between the transmitting antenna and the receiving antenna and configured to adjust a degree of coupling between the transmitting antenna and the receiving antenna, wherein the adjustment section includes a passive element, a ground, and a switch operable to connect the passive element to the ground; and

a control section configured to close the switch to connect the passive element to the ground, in the normal transmitting/receiving mode, and to open the switch to disconnect the passive element from the ground, in the distortion correction mode.

2. The radio communication apparatus according to claim 1, further comprising a gain control section configured to set a gain in at least one of the power amplifier and the low noise amplifier,

wherein the control section configured to control the degree of coupling based on the gain set by the gain control section.

3. The radio communication apparatus according to claim 1, wherein:

the switch is formed by a variable capacitance.

4. The radio communication apparatus according to claim 1 wherein an electric field surface of the transmitting antenna and an electric field surface of the receiving antenna are arranged to face each other.

5. The radio communication apparatus according to claim 1 wherein the transmitting circuit, the receiving circuit, and the switch are formed by a monolithic microwave integrated circuit.

6. The radio communication apparatus according to claim 1, wherein the switch includes two switch elements arranged and operable to connect two ends of the passive element, respectively, to the ground.

7. The radio communication apparatus according to claim 1, wherein the transmitting and receiving antennas are patch antennas.

8. The radio communication apparatus according to claim 1, wherein the transmitting and receiving antennas are dipole antennas.

9. The radio communication apparatus according to claim 1, wherein a magnetic field surface of the transmitting antenna and a magnetic field surface of the receiving antenna are arranged to face each other.

10. The radio communication apparatus according to claim 1, wherein the adjustment section is configured:

to close the switch to thereby connect the passive element to the ground;

(i) in the normal transmitting/receiving mode, and (ii) in the distorting correction mode in case the gain is set high in both of the power amplifier and the low noise amplifier; and

to open the switch to thereby disconnect the passive element from the ground, in the distorting correction mode in case the gain is set low in either or both of the power amplifier and the low noise amplifier.

11. A radio communication apparatus that has a normal transmitting/receiving mode and a distortion correction mode, the apparatus comprising:

a transmitting circuit that includes a transmitting processing circuit configured to generate a high frequency signal from a transmitting baseband signal by radio transmitting process and a power amplifier configured to amplify the high frequency signal;

a transmitting antenna formed by a plurality of antenna elements and configured to transmit the high frequency signal amplified by the power amplifier;

a receiving antenna configured to receive the high frequency signal transmitted by the transmitting antenna;

a receiving circuit that includes a low noise amplifier configured to amplify the high frequency signal received by the receiving antenna and a receiving processing circuit configured to generate a receiving baseband signal by demodulating the high frequency signal amplified by the low noise amplifier;

a distortion detecting section configured to detect a distortion component using the transmitting baseband signal and the receiving baseband signal;

an adjustment section configured to adjust a degree of coupling between the transmitting antenna and the receiving antenna, wherein the adjustment section is formed by a plurality of phase shifters that are respectively provided between the plurality of antenna elements and the power amplifier; and

a control section configured to switch the degree of coupling depending on the normal transmitting/receiving mode or the distortion correction mode, the control section being configured to, in the distortion correction mode, adjust directivity of the transmitting antenna to the receiving antenna for directing the high frequency signal transmitted from the transmitting antenna to the receiving antenna by controlling the phases of the plurality of phase shifters.

12. The radio communication apparatus according to claim 11, wherein the transmitting antenna is formed by N number of antenna elements and the adjustment section is formed by N number of phase shifters, and the N number of phase shifters respectively control phases of signals inputted to the N number of antenna elements.

13. The radio communication apparatus according to claim 12, wherein N is four.

14. The radio communication apparatus according to claim 11, wherein the control section is configured to determine phases for the plurality of phase shifters based on a gain set in at least one of the power amplifier and the low noise amplifier.

15. A radio communication method that is applied to a radio communication apparatus to have a normal transmitting/receiving mode and a distortion correction mode, the method comprising:

generating a high frequency signal from a transmitting baseband signal by radio transmitting process;

generating a transmitting signal by amplifying the high frequency signal;

transmitting the transmitting signal via a transmitting antenna;

receiving the transmitting signal via a receiving antenna and outputting it as a received signal;

amplifying the received signal;

generating a receiving baseband signal by demodulating the amplified received signal;

detecting a distortion component using the transmitting baseband signal and the receiving baseband signal;

adjusting a degree of coupling between the transmitting antenna and the receiving antenna by using an adjustment section arranged between the transmitting antenna and the receiving antenna, the adjustment section including a passive element, a ground, and a switch operable to connect the passive element to the ground;

closing the switch to connect the passive element to the ground, in the normal transmitting/receiving mode; and

opening the switch to disconnect the passive element from the ground, in the distortion correction mode.

16. The radio communication method according to claim 15, wherein the step of adjusting includes adjusting the degree of coupling based on at least one of a gain used in the amplifying of the high frequency signal and a gain used in the amplifying of the received signal.

17. The radio communication method according to claim 15, wherein the switch s formed by a variable capacitance.

18. The radio communication method according to claim 15, wherein the step of adjusting includes:

closing the switch to thereby connect the passive element to the ground;

(i) in the normal transmitting/receiving mode, and (ii) in the distorting correction mode in case a high gain is used in the amplifying of both of the high frequency signal and the received signal; and

opening the switch to thereby disconnect the passive element from the ground, in the distortion correction mode in case a low gain is used in either or both of the amplifying of the high frequency signal and the amplifying of the received signal.