Method for controlling transmission/reception timing of base station antenna for TDD wireless communications and base station antenna using the same

• US 9,154,177 B2
• Filed: 04/16/2010
• Issued: 10/06/2015
• Est. Priority Date: 04/20/2009
• Status: Active Grant

• Current Assignee: KMW Incorporated
• Original Assignee: KMW Incorporated
• Inventors: Kim, Duk-Yong
• Primary Examiner(s): Harper, Kevin C
• Assistant Examiner(s): Rose, Derrick V
• Application Number:
  US13/265,276
• Publication Number:
  US 20120033559A1
• Time in Patent Office: 1,999 Days
• Field of Search: 370/335, 370/342, 370/294, 370/350, 455/553.1
• US Class Current: 1/1
• CPC Class Codes: H04B 1/18 Input circuits, e.g. for coupling to an antenna or a transmission line coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H
• CPC Class Codes: H04B 1/48 in circuits for connecting transmitter and receiver to a common transmission path, e.g. by energy of transmitter H04B1/46 takes precedence
• CPC Class Codes: H04B 1/54 using the same frequency for two directions of communication H04B1/44 takes precedence
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

A method for controlling a transmission/reception timing of a BS antenna for TDD wireless communications is provided, in which a control signal and an RF signal are separated from a modulated signal received from a BTS, a TDD synchronization signal is monitored from the received modulated signal, a periodic RF signal is checked from downlink transmission and uplink reception RF signals, an error between the TDD synchronization signal and the periodic RF signal is calculated, and a transmission/reception switching control signal is output according to the error.

Claims

1. A method for controlling a transmission and reception timing of a Base Station (BS) antenna for Time Division Duplexing (TDD) wireless communications, the method comprising:

separating a control signal and a downlink Radio Frequency (RF) signal from a modulated signal received from a base station;

monitoring a TDD synchronization signal derived from the received modulated signal;

detecting the downlink RF signal in a transmission path of the BS antenna;

checking a periodic signal derived from at least the detected downlink RF signal and indicating respective downlink RF transmission and uplink RF reception time periods;

calculating an error comprising a timing difference between the TDD synchronization signal and the periodic signal; and

outputting at least one transmission and reception switching control signal to a reception signal amplifier that isolates a downlink transmission mode path and prevents introduction of a downlink transmission signal into an uplink reception path containing a reception amplifier and an isolator in response to the error equaling or exceeding a predetermined threshold.

2. The method of claim 1, wherein the outputting of a transmission and reception switching control signal comprises:

outputting a transmission and reception switching control signal based on the TDD synchronization signal, if the error is less than the predetermined threshold; and

outputting a transmission and reception switching control signal fixed to a downlink transmission timing, if the error is equal to or larger than the predetermined threshold.

3. The method of claim 1, further comprising determining whether errors have occurred to the base station and the BS antenna, wherein the outputting of a transmission and reception switching control signal comprise outputting the transmission and reception switching control signal, further taking into account the determination.

4. The method of claim 1, wherein the periodic signal checking comprises:

detecting the downlink transmission and uplink reception RF signals from a signal transmission path; and

setting a period for which the detected RF signals have a signal strength equal to or higher than a predetermined value as a downlink transmission period, and setting a remaining period as an uplink reception period.

5. A Base Station (BS) antenna device for Time Division Duplexing (TDD) wireless communications, comprising:

a signal separator for separating a Radio Frequency (RF) signal, a control signal for antenna control, and an operation power from a signal received from a base station;

a division/phase shift module for dividing the RF signal received from the signal separator, shifting a phase of each of the divided signals according to a phase control signal, and outputting the phase-shifted signals to a reception signal amplifier component containing both an uplink reception path and a downlink reception path, the uplink reception path comprising a reception amplifier and an isolator;

an RF coupler disposed in an RF signal path of the BS antenna for coupling at least the downlink RF signal and generating a coupled signal;

an RF detector for detecting at least the downlink RF signal from the coupled signal;

a converter for receiving the operation power from the signal separator and providing the operation power to the reception signal amplifier;

the reception signal amplifier connected to a radiation element of the BS antenna, for amplifying an uplink signal received from the radiation element and outputting the amplified uplink signal; and

a Main Control Module (MCM) for receiving the control signal and the operation power from the signal separator, monitoring a TDD synchronization signal from the control signal, checking a periodic signal derived from at least the downlink RF signal detected by the RF detector, calculating an error between the TDD synchronization signal and the periodic signal, outputting at least one transmission and reception switching control signal that isolates the downlink transmission mode path and prevents introduction of a downlink transmission signal into the uplink reception path in response to the error equaling or exceeding a predetermined threshold.

6. The BS antenna device of claim 5, wherein the MCM outputs a transmission and reception switching control signal based on the TDD synchronization signal, if the error is less than the predetermined threshold, and outputs a transmission and reception switching control signal fixed to a downlink transmission timing, if the error is equal to or larger than the predetermined threshold.

7. The BS antenna device of claim 5, wherein the MCM receives an error occurrence sensing signal from the base station and the reception signal amplifier and outputs the transmission and reception switching control signal, further taking into account whether an error has occurred.

8. The BS antenna device of claim 5, wherein a period for which the detected RF signals have a signal strength equal to or higher than a predetermined value is set as a downlink transmission period, and a remaining period is set as an uplink reception period.

9. The BS antenna device of claim 5, wherein the reception signal amplifier transmits a downlink transmission signal to the radiation element and comprises:

a first switch for switching to a transmission or reception path according to the transmission and reception switching control signal;

a second switch connected to the radiation element, for switching to the transmission or reception path according to the transmission and reception switching control signal, wherein the first and second switches close the downlink transmission mode path;

a Band Pass Filter (BPF) for receiving a signal from the second switch and filtering a frequency of a predetermined reception band during reception; and

the reception amplifier is a Low Noise Amplifier (LNA) for low-noise-amplifying a signal received from the BPF and outputting the low-noise-amplified signal to the first switch.

10. The BS antenna device of claim 5, wherein the reception signal amplifier transmits a downlink transmission signal to the radiation element and comprises:

a first switch for switching to a transmission or reception path according to the transmission and reception switching control signal;

a band pass filter (BPF) connected to the radiation element, for passing a frequency of transmission and reception bands;

a second switch connected to the BPF, for switching to the transmission or reception path according to the transmission and reception switching control signal; and

the reception amplifier is a low noise amplifier (LNA) for receiving a signal from the second switch, low-noise-amplifying the received signal, and outputting the low-noise-amplified signal to the first switch.

11. The BS antenna device of claim 9, further comprising an isolator between the first switch and the LNA.

12. The BS antenna device of claim 11, further comprising:

at least one auxiliary LNA connected to the LNA in parallel, for redundancy; and

an auxiliary switch structure for establishing a path between the LNA and the at least one auxiliary LNA.

13. The BS antenna device of claim 12, further comprising an isolator between the first switch and the auxiliary switch structure.

14. The BS antenna device of claim 12, further comprising an isolator between the first switch and the LNA.

15. The BS antenna device of claim 7, wherein the MCM receives an error occurrence sensing signal from the base station and the reception signal amplifier and outputs the transmission and reception switching control signal, further taking into account whether an error has occurred.

16. The BS antenna device of claim 5, wherein the MCM receives an error occurrence sensing signal from the base station and the reception signal amplifier and outputs the transmission and reception switching control signal, further taking into account whether an error has occurred.

17. The BS antenna device of claim 15, further comprising an isolator between the first switch and the auxiliary switch structure.

18. A system for controlling a transmission and reception timing of a Base Station (BS) antenna for Time Division Duplexing (TDD) wireless communications, comprising:

at least one control module for,

separating a control signal and a downlink Radio Frequency (RF) signal from a modulated signal received from a base station;

monitoring a TDD synchronization signal derived from the received modulated signal;

detecting the downlink RF signal in a transmission path of the BS antenna;

checking a periodic signal derived from at least the detected downlink RF signal and indicating respective downlink RF transmission and uplink RF reception time periods;

calculating an error comprising a timing difference between the TDD synchronization signal and the periodic signal; and

outputting at least one transmission and reception switching control signal to a reception signal amplifier that isolates a downlink transmission mode path and prevents introduction of a downlink transmission signal into an uplink reception path containing a reception amplifier and an isolator in response to the error equaling or exceeding a predetermined threshold.