Method and device for adjusting carrier frequency of multiple-input multiple output microwave device

• US 9,392,602 B2
• Filed: 12/26/2014
• Issued: 07/12/2016
• Est. Priority Date: 06/30/2012
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Zeng, Zhuo, Lv, Wenlong, Luo, Yanxing, Liu, Yu, Yan, Min
• Primary Examiner(s): Puente, Eva
• Application Number:
  US14/583,383
• Publication Number:
  US 20150110214A1
• Time in Patent Office: 564 Days
• Field of Search: 375/340, 455/118, 455/207, 455/9, 455/3.02
• US Class Current: 1/1
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04L 2027/0016 Stabilisation of local oscillators
• CPC Class Codes: H04L 7/033 using the transitions of the received signal to control the phase of the synchronising-signal-generating means, e.g. using a phase-locked loop
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

The present invention provides a method and a device for adjusting a carrier frequency of a multiple-input multiple-output microwave device. The method includes: obtaining, by an indoor unit IDU, a frequency of a radio frequency-reference crystal oscillator and a first frequency multiplication factor of each outdoor unit ODU; selecting, by the indoor unit IDU, one of the frequencies of the radio frequency-reference crystal oscillator as a reference frequency; adjusting, by the indoor unit IDU, a carrier frequency of the multiple-input multiple-output microwave device according to the first frequency multiplication factor and a radio frequency offset between the reference frequency and the frequency of the radio frequency-reference crystal oscillator of each ODU.

Claims

1. A method for adjusting a carrier frequency of a multiple-input multiple-output microwave device, comprising:

obtaining, by an indoor unit (IDU), a frequency of a radio frequency-reference crystal oscillator and a first frequency multiplication factor of each outdoor unit (ODU), wherein the first frequency multiplication factor is a ratio of a transmit frequency design value of a remote radio frequency unit corresponding to each ODU to the frequency of the radio frequency-reference crystal oscillator of the ODU;

selecting, by the IDU, one of the frequencies of the radio frequency-reference crystal oscillators as a reference frequency, wherein an ODU corresponding to the reference frequency is a reference ODU; and

adjusting, by the IDU, a carrier frequency of the multiple-input multiple-output microwave device according to the first frequency multiplication factor and a radio frequency offset between the reference frequency and the frequency of the radio frequency-reference crystal oscillator of each of the other ODUs, wherein the other ODUs refer to all the ODUs except the reference ODU.

2. The method for adjusting a carrier frequency of a multiple-input multiple-output microwave device according to claim 1, wherein the adjusting the carrier frequency of the multiple-input multiple-output microwave device according to the first frequency multiplication factor and the radio frequency offset between the reference frequency and the frequency of the radio frequency-reference crystal oscillator of each of the other ODUs comprises:

obtaining a radio frequency offset of each ODU according to a difference between the frequency of the radio frequency-reference crystal oscillator of the ODU and the reference frequency;

adjusting, according to the radio frequency offset, an intermediate frequency of an intermediate-frequency signal output to a corresponding ODU, wherein the adjusted intermediate frequency=an intermediate frequency corresponding to the reference frequency−

the radio frequency offset×

the first frequency multiplication factor; and

sending the adjusted intermediate-frequency signal to each ODU, so that carrier frequencies output by the ODUs are the same.

3. The method for adjusting a carrier frequency of a multiple-input multiple-output microwave device according to claim 2, wherein the adjusting, according to the radio frequency offset, the intermediate frequency of the intermediate-frequency signal output to the corresponding ODU, wherein the adjusted intermediate frequency=the intermediate frequency corresponding to the reference frequency−

the radio frequency offset×

the first frequency multiplication factor comprises;

adjusting the intermediate frequency of each intermediate-frequency signal by using a frequency offset correction phase-locked loop according to each radio frequency offset between the reference frequency and the frequency of the radio frequency-reference crystal oscillator of each ODU; and

when a difference between the intermediate frequency and a reference intermediate frequency corresponding to the reference frequency equals a product of the radio frequency offset and the first frequency multiplication factor, locking the frequency offset correction phase-locked loop.

4. The method for adjusting a carrier frequency of a multiple-input multiple-output microwave device according to claim 1, wherein the obtaining the frequency of the radio frequency-reference crystal oscillator and the first frequency multiplication factor of each ODU comprises:

directly receiving a clock signal of the radio frequency-reference crystal oscillator and a value of the first frequency multiplication factor that are sent by the ODU and obtaining the frequency of the radio frequency-reference crystal oscillator according to the clock signal of the radio frequency-reference crystal oscillator;

or,

receiving a management information carrier signal, a value of the first frequency multiplication factor, and a value of a second frequency multiplication factor that are sent by the ODU, wherein a frequency of the management information carrier signal=the frequency of the radio frequency-reference crystal oscillator×

the second frequency multiplication factor, and the second frequency multiplication factor is a ratio of the frequency of the management information carrier signal to the frequency of the radio frequency-reference crystal oscillator, and

obtaining a value of the frequency of the radio frequency-reference crystal oscillator according to the management information carrier signal and the value of the second frequency multiplication factor;

or

receiving management information, a value of the first frequency multiplication factor, and a value of a second frequency multiplication factor that are sent by the ODU, wherein the management information comprises a value of the frequency of the radio frequency-reference crystal oscillator after frequency multiplication, and the value of the frequency of the radio frequency-reference crystal oscillator after frequency multiplication=the frequency of the radio frequency-reference crystal oscillator×

the second frequency multiplication factor,

obtaining, from a management information carrier packet through Clock Data Recovery (CDR), the value of the frequency of the radio frequency-reference crystal oscillator after frequency multiplication, and

obtaining the value of the frequency of the radio frequency-reference crystal oscillator according to the management information and the value of the second frequency multiplication factor.

5. An apparatus for adjusting a carrier frequency of a multiple-input multiple-output microwave device, comprising:

an obtaining module, configured to obtain a frequency of a radio frequency-reference crystal oscillator and a first frequency multiplication factor of each outdoor unit (ODU), wherein the first frequency multiplication factor is a ratio of a transmit frequency design value of a remote radio frequency unit corresponding to each ODU to the frequency of the radio frequency-reference crystal oscillator of the ODU;

a selecting module, configured to select one of the frequencies of the radio frequency-reference crystal oscillators as a reference frequency, wherein an ODU corresponding to the reference frequency is a reference ODU; and

an adjusting module, configured to adjust a carrier frequency of the multiple-input multiple-output microwave device according to the first frequency multiplication factor and a radio frequency offset between the reference frequency and the frequency of the radio frequency-reference crystal oscillator of each of the other ODUs, wherein the other ODUs refer to all the ODUs except the reference ODU.

6. The apparatus for adjusting a carrier frequency of a multiple-input multiple-output microwave device according to claim 5, wherein the adjusting module comprises:

a first obtaining sub-module, configured to obtain a radio frequency offset of each ODU according to a difference between the frequency of the radio frequency-reference crystal oscillator of the ODU and the reference frequency;

an intermediate frequency obtaining sub-module, configured to adjust, according to the radio frequency offset, an intermediate frequency of an intermediate-frequency signal output to a corresponding ODU, wherein the adjusted intermediate frequency=an intermediate frequency corresponding to the reference frequency−

the radio frequency offset×

the first frequency multiplication factor; and

a returning sub-module, configured to send the adjusted intermediate-frequency signal to each ODU, so that carrier frequencies output by the ODUs are the same.

7. The apparatus for adjusting a carrier frequency of a multiple-input multiple-output microwave device according to claim 6, wherein the intermediate frequency obtaining sub-module is configured to:

adjust the intermediate frequency of each intermediate-frequency signal by using a frequency offset correction phase-locked loop according to each radio frequency offset between the reference frequency and the frequency of the radio frequency-reference crystal oscillator of each ODU; and

when a difference between the intermediate frequency and a reference intermediate frequency corresponding to the reference frequency equals a product of the radio frequency offset and the first frequency multiplication factor, lock the frequency offset correction phase-locked loop.

8. The apparatus for adjusting a carrier frequency of a multiple-input multiple-output microwave device according to claim 5, wherein the obtaining module is configured to:

directly receive a clock signal of the radio frequency-reference crystal oscillator and a value of the first frequency multiplication factor that are sent by the ODU and obtain the frequency of the radio frequency-reference crystal oscillator according to the clock signal of the radio frequency-reference crystal oscillator;

or

receive a management information carrier signal, a value of the first frequency multiplication factor, and a value of a second frequency multiplication factor that are sent by the ODU, wherein a frequency of the management information carrier signal=the frequency of the radio frequency-reference crystal oscillator×

the second frequency multiplication factor, and the second frequency multiplication factor is a ratio of the frequency of the management information carrier signal to the frequency of the radio frequency-reference crystal oscillator, and obtain a value of the frequency of the radio frequency-reference crystal oscillator according to the management information carrier signal and the value of the second frequency multiplication factor;

or,

receive management information, a value of the first frequency multiplication factor, and a value of a second frequency multiplication factor that are sent by the ODU, wherein the management information comprises a value of the frequency of the radio frequency-reference crystal oscillator after frequency multiplication, and the value of the frequency of the radio frequency-reference crystal oscillator after frequency multiplication=the frequency of the radio frequency-reference crystal oscillator×

the second frequency multiplication factor,

obtain, from a management information carrier packet through Clock Data Recovery (CDR), the value of the frequency of the radio frequency-reference crystal oscillator after frequency multiplication, and

obtain the value of the frequency of the radio frequency-reference crystal oscillator according to the management information and the value of the second frequency multiplication factor.

9. An indoor unit (IDU), comprising the apparatus for adjusting a carrier frequency of a multiple-input multiple-output microwave device according to claim 5.