CN101227211B - Method and apparatus for calibration of power of receiving main broadband - Google Patents

Abstract

The receiving total broadband power calibration device of the present invention comprises: a matching load connected to a duplexer; a duplexer used to transmit the signal received by the antenna to a down converter; a down converter used to convert the frequency of the signal, and The frequency-converted signal is transmitted to the receiving total broadband power detection unit; the receiving total broadband power detection unit is used to detect the received total broadband power according to the signal and report the received total broadband power to the control unit; and the control unit is used to receive the total broadband power The broadband power is compared with the equivalent noise floor to obtain the compensation value and the compensation value is saved for calibration. Through the present invention, the calibration accuracy of RTWP is improved, and the method can increase the calibration accuracy to within ±1dB, which is far superior to the requirements of the 3GPP agreement, and at the same time, no other instruments and equipment are needed, and the operation is simpler than before.

Description

Received total broadband power calibration method and device

technical field

The present invention relates to the communication field, in particular to a method and device for calibrating received total broadband power.

Background technique

The 3GPP protocol 25.133 requires the absolute accuracy of the value reported by the uplink channel RTWP to be ±4dB and the relative accuracy to be ±0.5dB. Because the transceiver board and duplexer are separated in the system, the existing calibration method is (as shown in Figure 1): at the test station, use signal source 102 from duplexer 104 ports (all transceiver boards are Use the same duplexer) to input a signal with an appropriate amplitude (such as -86dBm) as a reference. After the down converter 106, the RTWP functional unit 108 of the transceiver board detects the signal amplitude, and reports it to the CPU 110, and then calculates , get the RTWP detection value, compare it with the actual input signal amplitude, get the compensation value, and write it into the storage unit.

In practical applications, since the combination of the transceiver board and the duplexer is uncertain, the errors introduced by the previous calibration scheme mainly include three items: a) The difference of the backplane loss (different batches, different sectors of the same batch) area, main diversity); b) the difference in the gain of different duplexers; c) the calibration error of the transceiver board (including the error of the signal source, the temperature change during the calibration process, and the error caused by external interference). If each error has a large deviation and is in the full temperature range, the addition of these three errors will exceed the accuracy required by the agreement.

There is a need for a calibration device and method that can improve the RTWP of the base station in the prior art, and improve the reporting accuracy of the RTWP, so as to be better than the requirements of the 3GPP protocol.

Contents of the invention

Aiming at one or more of the above problems, the present invention provides a device and method for calibrating received total broadband power, which can improve the calibration accuracy of RTWP without requiring other instruments and equipment, and the operation is simpler and easier than before.

The receiving total broadband power calibration device of the present invention comprises: a matching load, connected to a duplexer; a duplexer, used to transmit the signal received by the antenna to a down converter; a down converter, used for frequency conversion of the signal, and The frequency-converted signal is transmitted to the receiving total broadband power detection unit; the receiving total broadband power detecting unit is used to detect the receiving total broadband power according to the signal and report the receiving total broadband power to the control unit; and the control unit is used to receive the receiving total broadband power The broadband power is compared with the equivalent noise floor to obtain the compensation value and the compensation value is saved for calibration.

In the receiving total broadband power calibration device of the present invention, the matching load is 50 ohms. In the case of engineering site calibration, the matching load is an external load. In the case of remote control calibration, the matching load is the built-in load.

In the received total broadband power calibration device of the present invention, the received total broadband power detection unit detects signals according to frequency steps.

The receiving total broadband power calibration method of the present invention includes the following steps: step S302, connecting the matching load to the duplexer; step S304, the duplexer transmits the signal received by the antenna to the down converter, and the down converter converts the frequency of the signal And transmit the frequency-converted signal to the receiving total broadband power detection unit; step S306, the receiving total broadband power detecting unit detects and receives the total broadband power according to the signal and reports the receiving total broadband power to the control unit; and step S308, the control unit receives The total wideband power is compared with the equivalent noise floor to obtain a compensation value and saved for calibration.

In the received total broadband power calibration method of the present invention, the matching load is 50 ohms. In the case of engineering site calibration, the matching load is an external load. In the case of remote control calibration, the matching load is the built-in load. The receiving total broadband power detection unit detects signals according to frequency steps.

Through the present invention, the calibration accuracy of RTWP is improved, and the method can improve the calibration accuracy to within ±1dB, which is far superior to the requirements of the 3GPP agreement, and at the same time, no other instruments and equipment are needed, and the operation is simpler and easier than before.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention and constitute a part of the application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention. In the attached picture:

Fig. 1 is a schematic diagram of an RTWP calibration method according to the prior art.

2 is a block diagram of a PTWP calibration device according to an embodiment of the invention; and

FIG. 3 is a flowchart of an RTWP calibration method according to an embodiment of the present invention.

Detailed ways

The specific implementation manners of the present invention will be described in detail below with reference to the accompanying drawings.

The invention relates to a method for calibrating the received total wideband power (RTWP) of a mobile communication base station, belongs to the field of mobile communication systems, and in particular relates to base station equipment in the mobile communication system.

Fig. 2 is a block diagram of an apparatus for calibrating received total broadband power according to an embodiment of the present invention. As shown in Figure 2, the receiving total broadband power calibration device of the present invention includes: a matching load 202, connected to a duplexer; a duplexer 204, used to transmit the signal received by the antenna to a down converter; a down converter 206 , used to convert the frequency of the signal, and transmit the frequency-converted signal to the receiving total broadband power detection unit; the receiving total broadband power detection unit 208 is used to detect the receiving total broadband power according to the signal and report the receiving total broadband power to the control unit and a control unit 210, configured to compare the received total broadband power with the equivalent noise floor to obtain a compensation value and store the compensation value for calibration.

Wherein, the matching load is 50 ohms. In the case of engineering site calibration, the matching load is an external load. In the case of remote control calibration, the matching load is the built-in load. The receiving total broadband power detection unit detects signals according to frequency steps.

A specific embodiment of the present invention is described below, as shown in Figure 2, the total noise power of receiver is:

N0＝KBT+Nf＝-174+10LogBW+Nf＝-174+10log3840000+Nf

In the above formula, KBT is the thermal noise power in the receiving broadband (-174dBm is the thermal noise power per Hz bandwidth at room temperature), if the bandwidth is 3.84M, plus the total noise figure of our current receiving channel (measured in 2.8dB ), then N0=-174+10LogBW+Nf=-174+65.84+2.8=-105.36dBm.

Therefore, -105.36dBm is the theoretical value of the equivalent noise floor of the uplink channel. The actual value may have a slight deviation, but the deviation should be within ±0.5dBm. Otherwise, it indicates that the noise figure has deteriorated and will exceed the allowable range of the required sensitivity.

The RTWP (RSSI) reported value of the uplink receiving channel is used to reflect the input signal amplitude of the antenna port (duplexer port) in real time, and is reported to the RNC through a public measurement report. The noise floor of the RTWP module of the transceiver board is about -65dBm, the channel gain is 49dB, and the line loss with the duplexer is calculated as 2dB. The equivalent floor noise of the antenna port is -105.4dBm, and the power before reaching the RTWP module is -58.4dBm, which is 6.6dB less than its floor noise. Therefore, the equivalent floor noise power at the input end is fully detected by the RTWP module after being amplified by the RF channel. , and is more accurate. In this way, after adding a 50-ohm matching load to the antenna port of the duplexer, the RTWP can be calibrated using the equivalent noise floor as a benchmark.

This method of calibrating the total broadband power received by the communication base station can be carried out directly at the project site, or remotely calibrated by controlling the background. When calibrating on site, connect a 50-ohm matching load to the antenna port of the duplexer for calibration; during remote calibration, switch to the built-in 50-ohm load for calibration. During calibration, the RTWP functional unit of the transceiver board performs signal detection sequentially according to the frequency step (such as 200KHz), and then reports to the CPU (that is, the control unit), and then calculates the RTWP detection value, which is equivalent to the bottom Noise -105.4dBm is compared to get the compensation value, which is written into the storage unit to complete the calibration of the entire frequency band.

The specific calibration steps are as follows.

Step 1: After logging into the system, if there is a cell at this time, block or delete the cell first.

Step 2: Select the antenna port to be calibrated. If it is on-site calibration, you need to connect a 50-ohm matching load to the corresponding antenna port.

Step 3: After the system is connected, you can calibrate the antenna port. After the calibration is successfully completed, switch to other antenna ports for calibration until all calibrations are completed.

FIG. 3 is a flowchart of an RTWP calibration method according to an embodiment of the present invention. As shown in Figure 3, the receiving total broadband power calibration method of the present invention includes the following steps: step S302, connecting the matching load to the duplexer; step S304, the duplexer transmits the signal received by the antenna to the down converter, and the down converter The frequency converter converts the signal and transmits the frequency-converted signal to the receiving total broadband power detection unit; step S306, the receiving total broadband power detection unit detects the receiving total broadband power according to the signal and reports the receiving total broadband power to the control unit; and the steps S308, the control unit compares the received total broadband power with the equivalent noise floor to obtain a compensation value and saves the compensation value for calibration.

In the received total broadband power calibration method of the present invention, the matching load is 50 ohms. In the case of engineering site calibration, the matching load is an external load. In the case of remote control calibration, the matching load is the built-in load. The receiving total broadband power detection unit detects signals according to frequency steps.

The device and method for calibrating the received total broadband power (RTWP) of a mobile communication base station proposed by the present invention are simple and easy to operate, do not need the support of other instruments and equipment, and have high calibration accuracy.

Compared with the prior art, the method of the present invention improves the calibration accuracy of RTWP, and the method can improve the calibration accuracy to within ±1dB, which is far superior to the requirements of the 3GPP agreement. At the same time, no other instruments and equipment are needed, and the operation is easy. Simpler than the original.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A receiving total broadband power calibration device, characterized in that the device comprises: a matching load connected to a duplexer; The duplexer is used to transmit the signal received by the antenna to the down converter; The down-converter is used to convert the frequency of the signal received by the antenna, and transmit the frequency-converted signal to the receiving total broadband power detection unit; The receiving total broadband power detecting unit is configured to detect the receiving total broadband power according to the frequency-converted signal and report the receiving total broadband power to a control unit; and The control unit is configured to compare the received total broadband power with an equivalent noise floor to obtain a compensation value and store the compensation value for calibration. 2. The receiving total broadband power calibration device according to claim 1, wherein the matching load is 50 ohms. 3. The receiving total broadband power calibration device according to claim 1 or 2, characterized in that, in the case of engineering site calibration, the matching load is an external load. 4. The receiving total broadband power calibration device according to claim 1 or 2, characterized in that, in the case of remote control calibration, the matching load is a built-in load. 5. The device for calibrating received total broadband power according to claim 1 or 2, characterized in that the received total broadband power detection unit detects signals according to frequency steps. 6. A method for receiving total broadband power calibration, characterized in that the method comprises the following steps: Step S302, connecting the matching load to the duplexer; Step S304, the duplexer transmits the signal received by the antenna to the down converter, and the down converter converts the frequency of the signal received by the antenna and transmits the frequency converted signal to the receiving total broadband power detection unit; Step S306, the received total broadband power detection unit detects the received total broadband power according to the frequency-converted signal and reports the received total broadband power to the control unit; and Step S308, the control unit compares the received total broadband power with the equivalent noise floor to obtain a compensation value and saves the compensation value for calibration. 7. The method for calibrating received total broadband power according to claim 6, wherein the matching load is 50 ohms. 8. The receiving total broadband power calibration method according to claim 6 or 7, characterized in that, in the case of engineering field calibration, the matching load is an external load. 9. The receiving total broadband power calibration method according to claim 6 or 7, characterized in that, in the case of remote control calibration, the matching load is a built-in load. 10. The receiving total broadband power calibration method according to claim 6 or 7, characterized in that the receiving total broadband power detection unit detects signals according to frequency steps.

Images