Cellular signal enhancer

• US 20040166802A1
• Filed: 02/26/2003
• Published: 08/26/2004
• Est. Priority Date: 02/26/2003
• Status: Abandoned Application

• Current Assignee: Andrew Corporation (CommScope Holding Company, Inc.)
• Original Assignee: EMS Technologies, Inc. (Honeywell International Inc.)
• Inventors: McNeill, Donald Joseph, Runyon, Donald L., Maxwell, James William, Thompson, Stephen Brett, McKay, David L. Sr.
• Application Number:
  US10/375,879
• Publication Number:
  US 20040166802A1
• Time in Patent Office: Days
• US Class Current: 455/15
• 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: H04B 7/1555 Selecting relay station antenna mode, e.g. selecting omnidirectional -, directional beams, selecting polarizations
• CPC Class Codes: H04W 16/26 Cell enhancers or enhancement, e.g. for tunnels, building shadow

Abstract

A low-cost user portable signal enhancer unit for extending service coverage of wireless communications to a user in a desired area of limited coverage. The enhancement supports an increase of signal power levels to allow wireless communication usage in a location, such as a small office or home office environment where the original cellular signals are weak or unreliable. A base station signal is enhanced by a bi-directional amplifier device (BDA), which receives a base station signal, amplifies the signal power and retransmits the amplified signal in a first signal path to a user in close proximity. The bi-directional amplifier also receives a user signal, amplifies the signal power and retransmits the amplified signal to the base station in a second separate signal path. Dual polarized antennas can receive and transmit the respective signals at opposite polarizations to increase isolation of the signals.

Claims

1. A signal enhancer for extending service coverage in a wireless communication system to at least one user in an area of limited coverage from a base station, comprising:

a bi-directional amplifier comprising an amplifying downlink signal path for generating an amplified base station signal in response to a base signal and an amplifying uplink signal path for generating an amplified user signal from each user in response to a user signal from the user;

a donor dual polarized antenna, coupled to the bi-directional amplifier, comprising a first donor dual polarized antenna having a first polarization state and a second donor dual polarized antenna having a second polarization state orthogonal to the first polarization state; and

a server dual polarized antenna, coupled to the bi-directional amplifier, comprising a first server dual polarized antenna having a first polarization state and a second server dual polarized antenna having a second polarization state orthogonal to the first polarization state,

wherein the downlink signal path is coupled between the first donor dual polarized antenna and the second server dual polarized antenna, and

wherein the uplink signal path is coupled between the second donor dual polarized antenna and the first server dual polarized antenna.

2. The enhancer defined in claim 1, wherein both of the signal paths are contained in a user portable unit and the bi-directional amplifier further comprises a variable gain control system for adjusting the gain of the signal path in response to detection of varying signal levels.

3. The enhancer defined in claim 2, wherein the variable gain control system is operative to increase the gain on both of the paths until one of a predetermined operating signal level is achieved or a maximum predetermined gain level has been achieved on the downlink signal path when power is applied to the unit.

4. The enhancer defined in claim 3, wherein the variable gain control system is operative to monitor the output power level of at least the downlink signal path and to decrease the power level for both of said the signal paths if the output power level exceeds a predetermined limit.

5. The enhancer defined in claim 3, wherein the variable gain control system is operative to monitor the output power level of at least the uplink signal path and to decrease the power level for the uplink signal path if the output power level exceeds a predetermined limit.

6. The enhancer defined in claim 2, wherein the variable gain control system is operative to monitor the output power level of the downlink signal path and to decrease the power level for both of the signal paths if the output power level exceeds a predetermined limit, the variable gain control being further operative to monitor the output power level of the uplink signal path and to decrease the power level for the uplink signal path if the output power level exceeds a predetermined limit.

7. The enhancer defined in claim 1 further comprising a mounting stand for mounting the unit in an appropriate location in relation to receipt of the base station signal from the base station.

8. The enhancer defined in claim 1, wherein the user area is located within a building structure having a low signal coverage characteristic.

9. The enhancer defined in claim 1 further comprising a free-standing mounting stand for mounting the unit in an appropriate location relative to receipt of the base station signal from the base station.

10. The enhancer defined in claim 1 wherein the antennas are located in a back-to-back arrangement adjacent one another.

11. The enhancer defined in claim 1, wherein each of the antennas comprise an antenna array having a plurality of patch radiators.

12. The enhancer defined in claim 11, wherein each of the antennas further comprise a parasitic patch antenna array spaced from each of the array antennas to increase the bandwidth of the antennas.

13. The enhancer defined in claim 1, wherein the bi-directional amplifier further comprises at least one bandpass filter in each of the uplink and the downlink signal paths, the filters having a transmission zero near a signal crossover for increasing the isolation between the signal paths.

14. A portable signal enhancer for extending service coverage in a wireless communications system, comprising:

a housing having a pair of oppositely facing surfaces and a size and weight that supports movement of the housing by hand from a first location to a second location;

a dual polarized antenna mounted to each of the surfaces for radiating energy in a direction opposite to that of the antenna mounted to the other surface, each dual polarization antenna comprising a first antenna element having a first polarization state and a second antenna element having a second polarization state, wherein the first polarization state is different from the second polarization state; and

a bidirectional amplifier (BDA), mounted within the housing, for amplifying signals between the dual polarized antenna on each of the pair of oppositely facing surfaces of the housing.

15. A method for controlling the gain in a downlink signal receiving path and the gain in an uplink signal transmitting signal path for a bidirectional amplifier (BDA) of a portable signal extender unit comprising the steps of:

responsive to initially supplying electrical power to the signal extender unit, establishing an initialization state for the BDA by increasing the gain of the downlink signal receiving path and the uplink signal transmitting path until a predetermined operating signal level is achieved for one of the paths or a maximum predetermined gain level is achieved for the downlink signal receiving path;

monitoring an output power level of the downlink signal receiving path and, in response to detection of the output power level exceeding a first threshold, decreasing the power level for the downlink signal receiving path and the uplink signal transmitting path; and

monitoring an output power level of the uplink signal receiving path and, in response to detection of the output power level exceeding a second threshold, decreasing the power level for the downlink signal receiving path and the uplink signal transmitting path.

16. The method of claim 15 further comprising the step of establishing a power down state by terminating the electrical power to the signal extender unit in response to detection of the output power level of one of the paths exceeding the first threshold or the second threshold for a certain time period.

17. A portable signal enhancer for extending service coverage in a wireless communications system, comprising:

a housing comprising a pair of oppositely facing surfaces;

a dual polarized antenna mounted to each of the surfaces for radiating energy in a direction opposite to that of the antenna mounted to the other surface, each dual polarization antenna comprising a first antenna element having a first polarization state and a second antenna element having a second polarization state, wherein the first polarization state is different from the second polarization state to achieve a separation of signals received by the first antenna element and output by the second antenna element; and

a bidirectional amplifier (BDA), mounted within the housing, for amplifying signals carried on a downlink signal path extending between the dual polarized antenna on each of the pair of oppositely facing surfaces of the housing and for amplifying signals carried on an uplink signal path extending between the dual polarized antenna on each of the pair of oppositely facing surfaces of the housing,

wherein the downlink signal path comprises a downlink filter for defining a full bandwidth path for the BDA, the downlink filter comprising signal delay optimization characteristics to minimize group delay in the downlink signal path, and

wherein the uplink signal path comprises an uplink filter for defining a full bandwidth path for the BDA, the uplink filter comprising signal delay optimization characteristics to minimize group delay in the uplink signal path.

18. A portable signal enhancer for extending service coverage in a wireless communications system, comprising:

a housing comprising a pair of oppositely facing surfaces;

a dual polarized antenna mounted to each of the surfaces for radiating energy in a direction opposite to that of the antenna mounted to the other surface, each dual polarization antenna comprising a first antenna element having a first polarization state and a second antenna element having a second polarization state, wherein the first polarization state is different from the second polarization state to achieve a separation of signals received by the first antenna element and output by the second antenna element; and

a bidirectional amplifier (BDA) for amplifying signals carried on a downlink signal path extending between the first antenna element having a first polarization state for a first one of the dual polarized antennas and the second antenna element having a second polarization state for the second one of the dual polarized antennas and for amplifying signals carried on an uplink signal path extending between the second antenna element having a second polarization state for the first one of the dual polarized antennas and the first antenna element having a first polarization state for the second one of the dual polarized antennas.

19. A portable signal enhancer for extending service coverage in a wireless communications system, comprising:

a housing having a pair of oppositely facing surfaces and an overall size and weight supporting movement of the housing by hand;

a dual polarized antenna mounted to each of the surfaces for radiating energy in a direction opposite to that of the antenna mounted to the other surface, each dual polarization antenna comprising a first antenna element having a first polarization state and a second antenna element having a second polarization state; and

a bidirectional amplifier (BDA), mounted within the housing, for amplifying signals carried on a downlink signal path extending between the dual polarized antenna on each of the pair of oppositely facing surfaces of the housing and for amplifying signals carried on an uplink signal path extending between the dual polarized antenna on each of the pair of oppositely facing surfaces of the housing,

the BDA further comprising a gain control system operative to monitor an output power level of the downlink signal path and to decrease the power level for the downlink signal path if the output power level exceeds a first threshold, the gain control system further operative to monitor the output power level of the uplink signal path and to decrease the power level for the uplink signal path if the output power level exceeds a second threshold.

20. The signal extender unit of claim 19, wherein the gain control unit is further operative to terminate electrical power to the BDA in response to detection of the output power level of one of the signal paths.