KR20050067298A - Method for controlling phase of multi-path transmitter and receiver - Google Patents

Abstract

The present invention relates to a method of controlling a phase of a transmitter or a receiver having a multipath. The present invention relates to a method for detecting a phase difference between channels by detecting an envelope of a multipath signal using a phase detection and a controller. The phase of the multipath signal is controlled by controlling the oscillator for each channel.

Description

Phase control method of multipath transceiver {METHOD FOR CONTROLLING PHASE OF MULTI-PATH TRANSMITTER AND RECEIVER}

The present invention relates to a transceiver of a mobile communication base station, and more particularly, to a phase control method of a multipath transceiver.

1 is a block diagram of a transmitter using a general digital up-converter (DUC).

As shown in FIG. 1, the transmitter has a structure in which channel signals output from a plurality of modems are combined and transmitted in a digital up-converter. The structure of the transmitter shown in FIG. 1 is configured with a digital predistorter function to reduce the size of the RF transmitter including the power amplifier of the mobile communication base station and increase efficiency.

2 and 3 are configuration diagrams of a transmitter of a mobile communication base station currently being developed and operated.

2 and 3 is formed of a combination of a plurality of transmitters. The channel signal of each transmitter output from multiple modems (modems # 1 to modem #n) is transmitted to the frequency (f1 to fn) of the local oscillator (LO # 1 to LO # n) in the RF up converter. The digital RF signals are combined in a high power combiner or a low power combiner and then transmitted through an antenna. In this case, a high power combiner is used when the power amplifier PA is connected to the output terminal of the RF up converter, and a low power combiner is used when the power amplifier is connected to the final stage.

However, when a plurality of transmitters as shown in FIG. 1 are used or in the transmitter structure as shown in FIGS. 2 and 3, a constant signal delay (phase error) is generated between output signals of the transmitters. Therefore, when combining multiple transmitters to increase the output power of the entire transmitter, the overall phase of each transmitter must be matched. If the phases are not matched, the power of the output signal is reduced or the signal is worst. This results in worse characteristics.

In addition, when using multiple antennas such as a smart antenna or a multi input multi output (MIMO), the signal phase of each channel must be matched or controlled for each transmitter.

Accordingly, an object of the present invention is to provide a phase control method of a multipath transceiver capable of matching the overall phase of a multipath transceiver.

Another object of the present invention is to provide a phase control method of a multipath transceiver capable of matching the signal phase of each channel when using multiple antennas such as smart antenna or MIMO.

In order to achieve the above object, in a transceiver having a multipath, a transceiver and a phase control method of a transceiver according to the present invention are provided in each transmitter by comparing a phase of an output signal of each transmitter using a phase detection and a controller. The phase of the channel signal for each path is controlled by controlling the oscillator.

Preferably, each transmitter is characterized in that the transceiver using a digital up converter (DUC).

Preferably, each transmitter is characterized in that the transceiver using a smart antenna or multiple antennas.

Preferably, the oscillator is characterized in that the digital oscillator.

Preferably, the digital oscillator is a NCO (Numerical Controlled Oscillatro) in a digital up converter (DUC).

Preferably, the oscillator is an analog oscillator for outputting an oscillation signal to the RF up converter.

Preferably, the analog oscillator comprises a phase shifter.

Hereinafter, preferred embodiments of the present invention will be described in detail.

In the current mobile communication base station, RF part occupies about half of the size of the entire base station. In particular, since the main RF unit reduces the power efficiency of the entire base station and increases the amount of heat generated, it is difficult to miniaturize the base station by adding an additional device considering heat dissipation. To overcome this drawback, Digital Up-Converter (DUC) technology, which combines channels (FA) in the digital part of the transmitter and transmits signals through one RF up-converter and power amplifier, Applied base stations are being developed.

In addition, the digital down-converter (DDC) technology, which converts multiple channels (FA) input through an antenna from a single RF down converter (Down-Converter) into digital signals and distributes them by channel, is applied to the receiver. have. Furthermore, in the 4th generation mobile communication systems, technologies such as smart antenna or multi input multi output (MIMO) are applied to increase channel capacity or to efficiently use resources. Accordingly, the present invention proposes a method capable of controlling the phase (delay) of a multipath transmitter required when applying the above techniques.

The multipath transmitter according to the present invention includes a phase detector and a phase controller for detecting an envelope of an output signal of each transmitter and outputting a phase difference, and an oscillator unit capable of controlling phase.

The phase detection and control unit controls a phase of a local oscillator or a NCO (Normal Controlled Oscillator) to minimize the detected phase error.

The oscillator is divided into analog and digital oscillators. An analog oscillator usually consists of a phase-locked loop (PLL) and usually includes a phase shifter that can control the phase of the output signal of the PLL. In addition, the digital oscillator (Digital Oscillator) is composed of NCO.

4 is a first embodiment of a multipath transmitter according to the present invention to which a digital oscillator is applied.

As shown in Fig. 4, in the multipath transmitter according to the present invention, the output signal of each modem is input to each transmitter through a digital routing multiplexer (DRM) 10, and the output signal of each transmitter is connected to the high power combiner 12. ) Is transmitted through the antenna. At this time, the phase detection and controller 13 receives a transmitter output signal (multipath signal) through a coupler, detects the phase difference of the multipath signal, and controls the DUCs 11-1 to 11-n to control the multipath signal. Control the phase difference.

That is, the phase detection and controller 13 compares the envelope of the output signal of the transmitters to detect the phase difference of the signal. First, the phase detection and controller 13 detects the phase difference between channel 1 (Ch 1) of DUC1 11-1 and DUC 2 (11-2), and then the NCO of DUC 2 (11-2) so that the phase difference is minimum. Adjust the phase of 2. When the phase difference is minimum, the phase detection and controller 13 detects the phase difference of Ch 2 and then adjusts the phase of NCO 2 of the DUC 2 11-2 so that the phase difference is minimum. Then adjust to Ch n in the same way.

In addition, the phase detection and controller 13 adjust the phase difference between DUC 1 and DUC 3 to Ch n in the same manner. Therefore, if the phase difference of the channel is adjusted to DUC 1 and DUC n, the phase difference of the entire transmission path will be the same.

5 is a diagram illustrating phase detection and characteristics of a phase detector in a controller.

In order to control the phase difference of the transmission path, the phase detection and controller 13 first set the NCO phase values of all paths to zero. In this state, the phase detection and the controller 13 store all phase values while changing the phases of all NCOs by 10 degrees, and then control the phase to the NCO value having the maximum phase detection value among them. Alternatively, phase detection and controller 13 may find the NCO value at which the value of the phase detector is maximum while varying all NCO phase values up and down by 10 degrees from the current value.

The phase detection and controller 13 adjusts the NCO phase of each transmission path so that the value of the phase detector is maximum while changing the current NCO phase value of each transmission path obtained by the above methods by 10 degrees up and down.

6 is a second embodiment of a multipath transmitter according to the present invention to which a digital oscillator is applied.

In the second embodiment of the present invention shown in FIG. 6, a plurality of power amplifiers PA and a high power coupling period connection structure shown in the first embodiment are changed between a low power combiner and a single power amplifier PA. The phase adjusting method is the same as in the first embodiment.

In the first and second embodiments of the present invention, the phase detection and controller controls the phase of the NCO, which is a digital oscillator in the DUC, but is not limited thereto, and may control the phase of the analog oscillator. An analog oscillator typically consists of a PLL and typically includes a phase shifter that can control the phase of the output signal from the PLL.

7 is a third embodiment of a multipath transmitter according to the present invention to which an analog oscillator is applied.

As shown in FIG. 7, each output signal of the modem 20 is converted into an analog signal and then converted into an RF signal in the RF up converters 21-1 to 21-n, and each RF signal is amplified by the power amplifier. And then coupled and transmitted at high power combiner 22. At this time, the phase detection and controller 23 detects the phase difference of each transmitter output signal and then connects the phase shifter connected between the local oscillators LO # 1 to LO # n and the RF upconverters 21-1 to 21-n. By controlling (24-1 to 24-n), the phases of the respective transmitters are matched by adjusting the phases of the oscillation signals f1 to fn inputted to the RF upconverters 21-1 to 21-n.

8 is a fourth embodiment of a multipath transmitter according to the present invention to which an analog oscillator is applied.

The fourth embodiment of the present invention shown in FIG. 8 is to change the connection structure between a plurality of power amplifiers (PA) and a high power coupling of the third embodiment to a connection structure between a low power combiner and a single power amplifier (PA), phase adjustment The method is the same as in the fourth embodiment.

9 is a fifth embodiment of a multipath transmitter according to the present invention to which a smart antenna is applied.

The structure of the multipath transmitter according to the present invention shown in FIG. 9 is a smart antenna transmission controller (SATC) 30 and the array antenna 32 in place of the DRM (10) and the high power combiner 12, FIG. It is identical to the structure of the multipath transmitter shown in Fig. 4.

Therefore, the phase detection and controller 33 compares the phase of each channel with respect to the transmission path and controls the phase of each path signal by controlling NCO # 1-NCO # n in the DUCs 31-1 to 31-n. .

In addition, although the present invention mainly describes a phase control method of a multipath transmitter, the phase control method is equally applicable to a receiver having a multipath, and a detailed description thereof will be omitted.

As described above, the present invention is generated when a plurality of transmitters are combined by detecting a phase error of an output signal (multipath signal) of each transmitter by using a phase detector and adjusting phases of digital and analog oscillators included in each transmitter. There is an effect that can match the phase error (time delay) between the new path.

In addition, although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely exemplary and will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. . Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a block diagram of a transmitter using a general digital up-converter (DUC).

2 and 3 is a block diagram of a transmitter of a mobile communication base station currently in operation.

4 illustrates a first embodiment of a multipath transmitter in accordance with the present invention having a digital oscillator.

5 shows phase detection and characteristics of a phase detector of a controller.

6 illustrates a second embodiment of a multipath transmitter in accordance with the present invention having a digital oscillator.

7 illustrates a third embodiment of a multipath transmitter in accordance with the present invention having an analog oscillator.

8 is a fourth embodiment of a multipath transmitter in accordance with the present invention having an analog oscillator.

9 illustrates a fifth embodiment of a multipath transmitter according to the present invention to which a smart antenna is applied.

***** Explanation of symbols for the main parts of the drawing *****

10: Digital Routing Multiplexer (DRM) 20: Modem

11-1 to 11-n, 31-1 to 31-n: DUC 21-1 to 21-n: RF upconverter

12: high power coupler 13, 23, 33: phase detection and phase controller

30: SATC 32: array antenna

34-1 to 34-n: phase shifter

Claims (18)

In the multi-path transmitter for combining and transmitting the signal for each path, Comparing the phase of the output signal of each transmitter to control the oscillator provided in each transmitter to adjust the phase of the channel signal for each path characterized in that the phase control method. The method of claim 1, wherein each transmitter is Phase control method characterized in that the transmitter using a digital up-converter (DUC). The method of claim 1, wherein each transmitter is Phase control method characterized in that the transmitter using a smart antenna or multiple antennas. The oscillator of claim 1, wherein the oscillator Phase control method characterized in that the digital oscillator. 5. The digital oscillator of claim 4 wherein the digital oscillator Phase control method characterized in that the NCO (Numerical Controlled Oscillatro) in a digital up converter (DUC). The oscillator of claim 1, wherein the oscillator A phase control method, characterized in that the analog oscillator for outputting the oscillation signal to the RF up converter. The method of claim 6, wherein the analog oscillator A phase control method comprising a phase shifter. A plurality of transmitters having an oscillator capable of controlling phase and converting and amplifying a modem signal into an RF signal and outputting channel signals for each path; A power combiner for combining and transmitting path-specific signals of a plurality of transmitters; And a phase detection and control unit for detecting a phase difference between output signals of the transmitter and controlling a phase of an oscillator in each transmitter to minimize the phase difference of each path signal. 9. The apparatus of claim 8, wherein each transmitter is A multi-way transmitter, characterized in that it is a transmitter using a digital up converter (DUC). 9. The apparatus of claim 8, wherein each transmitter is And a transmitter using a smart antenna or multiple antennas. 9. The oscillator of claim 8 wherein the oscillator Multipath transmitter, characterized in that the digital oscillator. 12. The digital oscillator of claim 11 wherein the digital oscillator A multipath transmitter characterized by a numerically controlled oscillatro (NCO) in a digital up converter (DUC). 9. The oscillator of claim 8 wherein the oscillator A multipath transmitter, characterized in that it is an analog local oscillator. The method of claim 13, wherein the analog local oscillator And a phase shifter for controlling the phase of the oscillation signal input to the RF up-converter. In a multipath transceiver having a multipath channel signal, Detecting a phase difference of each path signal by detecting an envelope of the multipath signal, and controlling a phase of the multipath signal by controlling an oscillator for each path based on the detected phase difference. 16. The oscillator of claim 15 wherein the oscillator A phase control method, characterized in that the local oscillator or NCO (Numerical Controlled Oscillator). A transceiver for transmitting and receiving a multipath channel signal; A multipath transceiver comprising: a phase detection and control unit for detecting a phase difference of a multipath signal and controlling an oscillator provided for each path in each transceiver to control a phase of the multipath. 18. The apparatus of claim 17, wherein the oscillator Multipath transceiver characterized in that the local oscillator or NCO (Numerical Controlled Oscillator).