High-frequency signal booster

• US 4,972,346 A
• Filed: 03/23/1988
• Issued: 11/20/1990
• Est. Priority Date: 03/24/1987
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Mihashi, Koji, Kawano, Minori
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Kuntz, Curtis
• Application Number:
  US07/172,057
• Time in Patent Office: 972 Days
• Field of Search: 455/17, 455/15, 455/16, 455/14, 455/19, 455/22, 455/23, 455/33, 455/9, 455/54, 455/56, 455/20, 455/21, 455/67, 455/226, 370/24, 370/75, 370/30, 379/59
• US Class Current: 455/9
• CPC Class Codes: H04B 7/15535 Control of relay amplifier gain amplifier gain control in general H03G3/00; gain control reducing self - or loop interference H04B7/15578
• CPC Class Codes: H04W 16/26 Cell enhancers or enhancement, e.g. for tunnels, building shadow

Abstract

A high-frequency signal booster which has at least one channel unit including a down-converter for converting input signals into intermediate-frequency signals and an up-converter for converting time into output signals. The respective up- and down-converters are separately equipped with station-originating signal oscillators. Further, the station-originating signal oscillator provided for the up-converter has a function of effecting the modulation with out-of-voice-band signals.

Claims

1. In a small-cell mobile radio communication system, a high-frequency signal booster for receiving, amplifying and reradiating high-frequency waves, including:

a first antenna system for receiving first input high-frequency signals from a base station and transmitting first output high-frequency signals to the base station;

a second antenna system for receiving second input high-frequency signals from a mobile station and transmitting second output high-frequency signals to the mobile station;

a first channel unit having predetermined first selectivity and connected to said first antenna system for performing selective amplification of the first input high-frequency signals in accordance with the first selectivity;

a second channel unit having predetermined second selectivity and connected to said second antenna system for performing selective amplification of the second input high-frequency signals in accordance with the second selectivity;

a first power amplifying means connected to said first channel unit for amplifying output signals of said first channel unit to increase power levels thereof and output the first output high-frequency signal to said first antenna system; and

a second power amplifying means connected to said second channel unit for amplifying outputs of said second channel unit to increase power levels thereof and output the second output high-frequency signal to said second antenna system;

wherein at least one of said first and second channel units includes a down-converter for converting all or part of said first or second input signal into an intermediate-frequency signal and an up-converter for converting said intermediate-frequency signal into the output signal of said one of the first and second channels units.

2. A high-frequency signal booster as set forth in claim 1, wherein a separate station-originating signal oscillator is connected to each of said up-converter and down-converter.

3. A high-frequency signal booster as set forth in claim 2, wherein at least said station-originating signal oscillator connected to said up-converter includes a modulating circuit.

4. In a small-cell mobile radio communication system, a high-frequency signal booster for receiving, amplifying and reradiating high-frequency waves, including:

a first antenna system for receiving first input high-frequency signals from a base station and transmitting first output high-frequency signals to the base station;

a second antenna system for receiving second input high-frequency signals from a mobile station and transmitting second output high-frequency signals to the mobile station;

branching means connected to said first and second antenna systems for supplying said first or second input high-frequency signal to two or more output portions thereof;

two or more channel units, each of which is connected to a different one of the output portions of said branching means and having predetermined selectivity for performing selective amplification of the first or second input high-frequency signal, wherein at least one channel unit includes a down-converter for converting all or part of the first or second input high-frequency signal into an intermediate-frequency signal and an up-converter for converting said intermediate-frequency signal into the output signal of said one channel unit;

combining means connected to said channel units for combining output signals of said channel units; and

a common power amplifying means connected to said combining means for amplifying outputs of said combining means to increase power levels thereof and output the first or second output high-frequency signal to said first or second antenna system.

5. A high-frequency signal booster as set forth in claim 4, wherein at least said one channel unit performs the function of selectively amplifying all or part of the first or second input signal in accordance with the predetermined selectivity.

6. A high-frequency signal booster as set forth in claim 4, including a station-originating signal oscillator connected to each of said up-converter and down-converter.

7. A high-frequency signal booster as set forth in claim 6, wherein said station-originating signal oscillator connected to at least said one up-converter includes a modulating circuit.

8. In a small-cell mobile radio communication system, a high-frequency signal booster for receiving, amplifying and reradiating high-frequency signals at the same frequency as that of the received signal, including:

a receiving antenna for receiving input high-frequency signals;

a transmitting antenna for transmitting output high-frequency signals;

a down-converter connected to said receiving antenna for converting the received input signals into intermediate-frequency signals;

an up-converter, which being connected to said down-converter and said transmitting antenna, for converting the intermediate-frequency signals into the output high-frequency signals to be transmitted from said transmitting antenna;

first station-originating signal generators connected to said down-converter for generating first station-originating signals to be inputted to said down-converters; and

second station-originating signal generators connected to said up-converter for generating second station-originating signals to be inputted to said up-converter,

wherein the output high-frequency signals are frequency-modulated with out-of-voice-band signals before transmitted from the transmitting antenna, and

wherein the out-of-voice-band signals are detected from the received input signals and further a gain of said high-frequency signal booster is controlled in accordance with the detected level of the out-of-voice-band signals.

9. A high-frequency signal booster as set forth in claim 8, wherein the second station-originating signals produced in said second station-originating signal generator are directly frequency-modulated with the out-of-voice-band signals in order to effect the modulation of the output high-frequency signals.

10. A high-frequency signal booster as set forth in claim 8, wherein the intermediate-frequency signals are amplified and further examined to detect the out-of-voice-band signals in the received input high-frequency signals.

11. In a small-cell mobile radio communication system, a high-frequency signal booster for receiving, amplifying and reradiating high-frequency waves at the same frequency as that of the signals received from a base station and a mobile station, said booster having:

an upstream antenna for receiving first input signals sent from a base station and transmitting first output signals to the base station;

an upstream antenna duplexer connected to said upstream antenna for accepting the receiving first input signals from said upstream antenna and sending the first output signals to said upstream antenna;

upstream branching means connected to said upstream antenna duplexer for accepting the first input signals and supplying the first input signals to output portions thereof;

upstream elements, each having a predetermined selectivity and connected to a different one of said output portions of said upstream branching means for selectively amplifying the first input signals accepted from said upstream branching means in accordance with the predetermined selectivity;

upstream combining means connected to said upstream elements for combining the amplified first input signals with first synthetic signals;

an upstream common amplifier connected to said upstream combining means for amplifying the first synthetic signals to produce the first output signals;

a downstream antenna for receiving second input signals sent from a base station and transmitting second output signals to the base station;

a downstream antenna duplexer connected to said downstream antenna for accepting the received second input signals from said downstream antenna and sending the second output signals to said downstream antenna;

downstream branching means connected to said downstream antenna duplexer for accepting the second input signals and supplying the second input signals to output portions thereof;

downstream elements, each having a predetermined selectivity and connected to a different one of said output portions of said downstream branching means for selectively amplifying the second input signals accepted from said downstream branching means in accordance with the predetermined selectivity;

downstream combining means connected to said downstream elements for combining the amplified second input signals with second synthetic signals; and

a downstream common amplifier connected to said downstream channel selecting means for amplifying the second synthetic signals to produce the second output signals,

wherein said base station antenna is a high-gain directional antenna;

said high-frequency signal booster further including;

first additional elements having predetermined narrow-band selectivity for every channel for use in operation in the upstream direction in which the radio signals transmitted from said base station are amplified and reradiated;

first relatively-narrow-band power amplifiers, each of which is connected in series to a different one of said first additional elements for further amplifying the output of said first additional elements;

second additional elements, at least one of which has narrow-band selectivity for one channel for use in operation in the downstream direction in which the radio waves transmitted from said mobile station are amplified and reradiated;

a second common power amplifier connected in series to said one of the second additional elements having narrow-band selectivity for amplifying the output of said second additional element.

12. A high-frequency signal booster as set forth in claim 11, wherein each of said first additional power amplifiers is composed of a class B or C relatively-narrow-band power amplifier, while said second common power amplifier is composed of a class A wide-band power amplifier.

13. A high-frequency booster as set forth in claim 11, wherein said one of the second additional elements has relatively-narrow-band selectivity, which is designed for a control channel, and another one of said second additional elements having wide-band selectivity, which is designed for a message channel, are provided for use in the operation in the downstream direction.

14. A high-frequency booster as set forth in claim 12, wherein said one of the second additional elements has relatively-narrow-band selectivity, which is designed for a control channel, and another one of said second additional elements having wide-band selectivity, which is designed for a message channel, are provided for use in the operation in the downstream direction.

15. A high-frequency booster as set forth in claim 11, 12, 13 or 14 wherein said first and second additional elements each of which having the relatively-narrow-band selectivity and being used as control channels in operations in the upstream and downstream directions, are so arranged that receiving and transmitting channels are shifted by at least one channel.

16. A high-frequency signal booster as set forth in claims 11, 12, 13 or 14, wherein the output high-frequency signals are frequency-modulated with out-of-voice-band signals before transmitted from the transmitting antenna, and wherein the out-of-voice-band signals are detected from the received inputted signals and further a gain of said high-frequency signal booster is controlled in accordance with the detected level of the out-of-voice-band signals.

17. A bordering system as set forth in claim 16, wherein said means for shifting frequencies of said received control signals at the given intervals includes a down-converter for temporarily converting said received control signals into intermediate-frequency signals, a band-pass filter connected to said down-converter for accepting the intermediate-frequency signals and passing only the control signals therethrough and an up-converter connected to said band-pass filter for accepting the control signal from said band-pass filter and re-converting the control signals into high-frequency signals.

18. A bordering system as set forth in claim 16, characterized in that said bordering system is disposed in the vicinity of a border between service areas of two adjacent base stations.

19. A bordering system as set forth in claim 16, wherein the base station is equipped with a high-gain antenna, of which a beam angle is relatively small, such as a paraboilic antenna, while said mobile station is equipped with a direction antenna of which a beam angle is relatively large.