WO2010069235A1

WO2010069235A1 - Method for signal processing, central station, base station and network system

Info

Publication number: WO2010069235A1
Application number: PCT/CN2009/075436
Authority: WO
Inventors: 于弋川
Original assignee: 华为技术有限公司
Priority date: 2008-12-15
Filing date: 2009-12-09
Publication date: 2010-06-24
Also published as: CN101431373A

Abstract

This invention discloses a method for signal processing, a central station, a base station and a network system. The method includes the following steps: a subcarrier signal carrying communication data is multiplexed; and the multiplexed subcarrier signal is transmitted. Wherein the multiplexing processing comprises single subcarrier multiplexing, a combination of subcarrier multiplexing and optical wavelength division multiplexing, and a combination of subcarrier multiplexing and optical add drop multiplexing. Only downlink carrier is multiplexed during optical wavelength division multiplexing, or downlink carrier and uplink carrier can be multiplexed simultaneously. Through the embodiment of this invention, the capacity of the optical fiber wireless system can be improved.

Description

Signal processing method, central station, base station and network system The present application claims to be Chinese patent issued on December 15, 2008, the application number is 200810239704.9, and the invention name is "signal processing method, central station, base station and network system" Chinese patent Priority of application. Technical field

The present invention relates to fiber optic wireless communication technologies, and more particularly to a signal processing method, a central station, a base station, and a network system. Background technique

At present, the working frequency bands of most wireless communication services are concentrated below 5 GHz, and the existing low-band frequency resources have almost been allocated. In the future, the operating frequency of the wireless carrier needs to be increased to increase the capacity of the wireless communication system, and the next generation is ultra-wide. The communication frequency used by wireless communication technology will extend to the millimeter band. However, when the electromagnetic wave of the millimeter wave band propagates in the atmosphere, the loss due to absorption and reflection will increase significantly, and the transmission distance will be limited. At the same time, the cost of the millimeter wave communication device is high, which is not conducive to personal communication; these factors limit the millimeter wave communication. The development of technology has introduced a Radio Over Fiber (ROF) system for this purpose.

In ultra-wideband wireless communication networks based on fiber-optic wireless technology, the number of base stations needs to be increased both from the high-quality effective coverage of wireless signals and from the perspective of system optimization. The inventors found in the process of implementing the present invention that the number of base stations in a fiber-optic wireless communication system is very large, and the corresponding demand for the number of optical fibers is relatively large, which will increase the construction cost of the network. Summary of the invention

Embodiments of the present invention provide a signal processing method, a central station, a base station, and a network system, which are used to solve a high-cost construction problem caused by increasing the number of optical fibers in a wireless system, such as a fiber-optic wireless network. question.

The embodiment of the invention provides a signal processing method, including:

The subcarrier signal carrying the communication data is multiplexed; the multiplexed subcarrier signal is transmitted through one or more optical fibers.

The embodiment of the invention provides a signal processing method, including:

Demodulating an optical carrier signal carrying a subcarrier signal to obtain a multiplexed subcarrier signal; demultiplexing the multiplexed subcarrier signal to obtain each subcarrier signal.

An embodiment of the present invention provides a central station, including:

a multiplexing module, configured to perform multiplexing processing on a subcarrier signal carrying communication data, and a sending module, configured to send the multiplexed subcarrier signal.

An embodiment of the present invention provides a base station, including:

a demodulation module, configured to demodulate an optical carrier signal carrying a subcarrier signal to obtain a multiplexed subcarrier signal;

And a demultiplexing module, configured to demultiplex the multiplexed subcarrier signals to obtain respective subcarrier signals. The embodiment of the invention provides a network system, including:

a first central station, configured to separately modulate communication data of each channel on a corresponding subcarrier, to obtain respective subcarrier signals; and modulate each subcarrier signal to an optical carrier of a single wavelength to obtain an optical carrier signal;

The first base station is configured to perform optical electrolytic modulation and subcarrier demultiplexing processing on the optical carrier signal corresponding to the optical carrier of the single wavelength.

The embodiment of the invention further provides a network system, including:

a second central station, configured to separately modulate communication data of each channel on a corresponding subcarrier to obtain each corresponding subcarrier signal; and respectively modulate each subcarrier signal to a downlink optical carrier of a different wavelength to obtain each corresponding a downlink optical carrier signal; performing optical wavelength division multiplexing processing on each downlink optical carrier signal to obtain a multiplexed optical carrier signal;

a light wave decomposition multiplexer, configured to demultiplex the multiplexed optical carrier signal, To each downlink optical carrier signal;

The second base station is configured to perform optical electrolytic modulation and subcarrier demultiplexing processing on the corresponding downlink optical carrier signals corresponding to the downlink optical carrier signals.

The embodiment of the invention further provides a network system, including:

a third central station, configured to separately modulate communication data of each channel on a corresponding subcarrier to obtain each corresponding subcarrier signal; and respectively modulate each subcarrier signal to a downlink optical carrier of a different wavelength to obtain each corresponding a downlink optical carrier signal; performing optical wavelength division multiplexing processing on the generated uplink optical carrier and each downlink optical carrier signal.

And a third base station, configured to perform optical add/drop multiplexing, optical electrolytic modulation, and subcarrier demultiplexing processing on the downlink optical carrier signal.

According to the foregoing technical solution, in the embodiment of the present invention, by multiplexing the subcarrier signals carrying data signals that need to be transmitted to each base station, signals that need to be transmitted to each base station can be multiplexed into one optical fiber, thereby improving The system capacity increases the number of base stations without increasing the number of fibers, reducing network costs. DRAWINGS

1 is a schematic flow chart of a method according to a first embodiment of the present invention;

2 is a schematic flow chart of a method according to a second embodiment of the present invention;

3 is a schematic diagram of a network structure corresponding to FIG. 2;

4 is a schematic flow chart of a method according to a third embodiment of the present invention;

FIG. 5 is a schematic diagram of a network structure corresponding to FIG. 4;

6 is a schematic flow chart of a method according to a fourth embodiment of the present invention;

7 is a schematic diagram of a network structure corresponding to FIG. 6;

FIG. 8 is a schematic structural diagram of a central station according to a fifth embodiment of the present invention; FIG.

9 is a schematic structural diagram of a base station according to a sixth embodiment of the present invention;

FIG. 10 is a schematic structural diagram of a system according to a seventh embodiment of the present invention; FIG. 11 is a schematic structural diagram of a system according to an eighth embodiment of the present invention;

Figure 12 is a schematic structural view of a system according to a ninth embodiment of the present invention. detailed description

The ROF system includes a central station (CS), a fiber link, and a base station; the downlink high-speed data signal is modulated onto the millimeter wave of light generated by the CS, and the optical millimeter wave with data is transmitted to the base station through the optical fiber at the base station. In the photoelectric conversion, the optical millimeter wave is converted into an electric millimeter wave, and transmitted through the antenna; in the uplink, the base station performs electro-optical conversion on the received uplink signal, and then transmits the signal to the central station for signal processing through the optical fiber. Since the loss of the optical fiber is extremely low and the capacity is large, the millimeter wave and the high speed data are simultaneously modulated on the optical carrier, and the transmission distance of the millimeter wave can be extended; and each base station shares the signal processing unit of the central station, thereby reducing expensive signal processing. The number of units saves costs and simplifies the structure of the system. Therefore, the ROF system can fully utilize the huge bandwidth of the optical fiber to reduce the cost and combine the flexibility of the wireless network, and integrate the wireless network and the optical network into a new type of connection that can increase the capacity and mobility of the access network and reduce the operating cost. Into the network, has broad prospects in the next generation of ultra-wide wireless communication technology

FIG. 1 is a schematic flowchart of a method according to a first embodiment of the present invention, including:

Step 11: The transmitting device, for example, a central station in the fiber-optic wireless network, performs multiplexing processing on the subcarrier signal carrying the communication data.

Among them, the subcarrier is the RF/millimeter wave generated by the central station.

Since the existing signal carriers are mainly concentrated in the low frequency band, the low frequency resources are tight, and even if it is adopted, it requires a great cost; and the millimeter wave belongs to the high frequency, and the communication frequency band that can be used is wide, for example, the millimeter wave at 60 GHz. There are about 7 GHz bands in the system that are free to use.

In this embodiment, a radio frequency/millimeter wave (subcarrier) is used as a carrier carrying communication data, which can cover an existing communication frequency band and a communication frequency band with a higher frequency that may be applied in the future.

Step 12: The transmitting end device sends the multiplexed subcarrier signal to the receiving end device, for example, a base station in the optical fiber wireless network. In this embodiment, by performing multiplexing processing, the system capacity can be increased, and then the network structure between the transmitting end and the receiving end can be optimized, and the cost can be reduced.

2 is a schematic flowchart of a method according to a second embodiment of the present invention, and FIG. 3 is a schematic diagram of a network structure corresponding to FIG. 2. This embodiment includes:

Step 21: The transmitting end, for example, the central station in the fiber-optic wireless communication system, generates RF/millimeter wave signals (ie, subcarriers) of different frequencies and optical carriers of a single wavelength, and the frequency of each subcarrier is _fsc , Λ ₂ , ..., f _SCm , the wavelength of the optical carrier is 4. Figure 3 takes two subcarriers as an example.

Step 22: Through the electrical modulator, the subcarriers are modulated by the data of the corresponding channel to obtain a subcarrier signal carrying data of the corresponding channel. For example, referring to Figure 3, the data of channel 1 is used to modulate the subcarriers of frequency f _sc , and the data of channel 2 is used to modulate the subcarriers of frequency / _se2 .

Step 23: Simultaneously modulating each subcarrier signal onto the optical carrier of the single wavelength by an optical modulator or a direct modulation laser, thereby realizing multiplexing of the multiple subcarrier signals in the same optical carrier. For example, referring to Figure 3, the two subcarrier signals are simultaneously modulated onto an optical carrier of wavelength Λ (the corresponding frequency is /.).

The subcarrier multiplexing of this embodiment can modulate the higher frequency subcarrier electrical signal onto the optical signal, i.e., modulate the analog signal on a higher frequency carrier. In the optical domain subcarrier multiplexing technology of this embodiment, each subcarrier signal is modulated on an optical carrier. Although analog signal modulation requires a larger bandwidth than digital signal modulation, the optical carrier can provide a bandwidth of the order of magnitude. Therefore, it is still possible to simultaneously multiplex a larger amount of subcarrier signals.

The current optical modulator is mainly used for optical communication technology, that is, for modulating digital signals. When modulating digital signals, the main performance indicators of the application of the optical modulator may include bandwidth and extinction ratio, etc. The optical modulator may also It is used to modulate the analog signal. When modulating the analog signal, it includes the linearity index of the modulator in addition to the bandwidth and extinction ratio. In another embodiment of the present invention, in order to achieve better performance, a linearity optimization scheme can be used to further optimize the linearity of the optical modulator.

Step 24: transmitting the subcarrier signal multiplexed on a single optical carrier to the receiving end through the optical fiber. For example, a base station corresponding to the optical carrier in a fiber-optic wireless communication system.

Step 25: At the receiving end, photoelectric conversion is performed by using a direct detection method of the photodetector, so that demodulation of the multiple subcarrier signals modulated onto the optical carrier can be completed at the same time.

Step 26: Demultiplexing the subcarrier signal by filter filtering. In order to improve the transmission of the signal in the wireless environment, a method of enhancing the transmission power may be adopted, that is, the RF/millimeter wave amplifier may be further amplified and directly fed to the antenna. Launched.

In this embodiment, the optical domain subcarrier multiplexing technology is adopted, wherein the optical carrier can select a frequency band of 4 艮 wide, so that the freely used frequency band can be fully utilized under existing conditions, for example, the free use of 7 GHz in a 60 GHz millimeter wave system can be fully utilized. Frequency band. At the same time, the signals of each channel can be modulated onto subcarriers in various different modulation formats, so that various broadband communication services can be carried. Moreover, no clock synchronization and fast sampling are required, and the structure is simple and the cost is low.

4 is a schematic flowchart of a method according to a third embodiment of the present invention, and FIG. 5 is a schematic diagram of a network structure corresponding to FIG. 4. This embodiment includes:

Step 41: At the transmitting end, using subcarrier multiplexing technology, at least two subcarriers (frequency are respectively

Or λ ₂ , ... or λ _η ). For a specific implementation of the multiple subcarrier signals being simultaneously modulated onto an optical carrier of a single wavelength, refer to the implementation of the second embodiment.

Step 42: At the transmitting end, each of the optical carriers carrying the subcarrier signals of at least two channels (wavelengths are respectively Λ, ..., ), wherein each optical carrier corresponds to the base station, such as a wavelength! ^ The optical carrier will be processed by the first base station. The optical carriers each carrying the subcarrier signal are wavelength division multiplexed by an optical wavelength division multiplexer (or multiplexer) to obtain a multiplexed subcarrier signal. Since the chirp subcarrier signals are respectively multiplexed onto the optical carriers of the loop, after the wavelength division multiplexing, a signal of the chirped loop is transmitted in the optical fiber.

Specifically, the subcarrier signals that are multiplexed in this embodiment are analog signals, and therefore, a large bandwidth is a necessary special requirement for devices and systems as compared with the prior art. At present, the wavelength division multiplexer used in optical transmission in optical communication technology particularly emphasizes a small channel spacing, that is, a so-called dense wavelength division multiplexing technology; and this embodiment needs to have a foot between each channel of the wavelength division multiplexer. Sufficient spacing can well isolate two adjacent channels carrying a large bandwidth subcarrier signal, requiring coarse wavelength division multiplexing.

During transmission, the optical signal can be amplified using a fiber amplifier to enhance the link gain of the RF/millimeter wave signal.

Step 43: The transmitting end combines the optical wave division multiplexed optical carriers into one optical fiber for transmission. Since optical carrier signals of different wavelengths can be regarded as independent of each other, multiplexing transmission of multiple optical carrier signals can be realized in one optical fiber.

Step 44: At the receiving end, an optical wave splitting multiplexer (or a splitter) is used to separate optical carriers carrying at least two subcarriers of different wavelengths to implement demultiplexing of the multiple optical carriers. Each optical carrier after demultiplexing will be sent to the corresponding base station, for example, the wavelength is! The optical carrier of ₁ is sent to the first base station, and the optical carrier of wavelength _η is sent to the second base station.

The frequencies of the subcarrier signals multiplexed onto the optical carrier of a single wavelength are different, and the frequencies of the subcarrier signals carried on the optical carriers of any two different wavelengths may be the same or different. The optical wavelength division multiplexer/demultiplexer can be an integrated optical wavelength division multiplexer/demultiplexer, a fiber type optical multiplexer/demultiplexer, and a thin film type optical multiplexer/demultiplexer.

Step 45: At each receiving end (base station), performing photoelectric conversion by using a direct detection method of the photodetector, and simultaneously performing demodulation of at least two subcarriers modulated on the optical carrier of the wavelength, and filtering is performed after filtering The demultiplexing of the subcarriers is amplified by the RF/millimeter wave amplifier and directly fed to the antenna for transmission. For details, refer to optical carrier demodulation and subcarrier demultiplexing in Embodiment 2.

In this embodiment, optical wavelength division multiplexing is further performed on the basis of the second subcarrier multiplexing. The optical wavelength division multiplexing technology can fully utilize the huge bandwidth resources of the optical fiber, and can effectively increase the communication capacity of the system without upgrading the existing transmission line. That is, when the base station is added, one fiber can still be used, and each base station is corresponding. The optical carriers are all multiplexed into the fiber. The optical carrier of each base station can be dynamically and optimally allocated according to the embodiment, so that the optical carrier carries different subcarrier signals according to requirements, and the optical fiber does not need to be added when the base station is added, which can greatly simplify the system network topology and facilitate the system. And the upgrade of the service, at the same time achieve effective management of the network. In addition, for some typical solutions in current wireless communication systems: solutions with different carriers of the same standard, for example, multi-carrier and multi-operator co-site, etc., or solutions of different systems and common sites, for example, global mobile communication System ( Global System for Mobile

Communications, GSM), Wideband Code Division Multiple Access (WCDMA) systems, Long Term Evolution (LTE) systems. These scenarios are the most widely used scenarios in the current and future. The common feature is that the same site uses multiple different wavelengths of radio carriers. The current solution is mainly to use completely different RF processing units, or to develop a new RF processing unit to support Different carrier requirements. Because the base station is deployed in a large amount in the network, the use of different RF processing units greatly increases the network construction cost. Even with the new RF processing unit, the deployment cost is high, and the related technologies are currently immature and the development cost is high. In summary, current solutions require a large number of complex RF processing units at the base station to increase costs. With the solution proposed by the embodiment of the present invention, the radio frequency processing unit can be set to the central station and shared by all the base stations, which can effectively reduce the deployment cost. In the embodiment shown in FIG. 2 and FIG. 4, the optical carrier sent by the transmitting end (such as the central station) is a downlink optical carrier, and the central optical station can also generate an uplink optical carrier, and the uplink optical carrier and the downlink optical carrier signal are simultaneously multiplexed. In an optical fiber; at the receiving end (such as a base station), the received uplink data is modulated onto the uplink optical carrier and sent to the central station. Alternatively, the central station does not generate an uplink optical carrier, and each base station generates a respective uplink optical carrier to modulate the corresponding uplink data. That is, the light source that generates the upstream optical carrier and the light source that generates the downstream optical carrier may be collectively disposed in the central station, or only the light source that generates the downstream optical carrier is disposed in the central station, and the light source that generates the upstream optical carrier is disposed in the base station. .

FIG. 6 is a schematic flowchart of a method according to a fourth embodiment of the present invention, and FIG. 7 is a schematic diagram of a network structure corresponding to FIG. 6. This embodiment includes:

Step 61: At the transmitting end, all optical carriers having different wavelengths (for transmission to each base station) for uplink and downlink are combined into one optical fiber through a wavelength division multiplexer. All of the optical carriers for the downlink are respectively modulated by a corresponding set of downlink subcarrier signals that have carried data. That is, as in the third embodiment, the multiplexing of the subcarrier signals on the optical carrier is implemented. In FIG. 7, the padded triangle represents the optical carrier carrying the data; and all the optical carriers used for the uplink remain unmodulated. The status is used for the uplink signals of the respective base stations, and the un-imposed triangles are represented in Fig. 7 by unfilled triangles.

Step 62: The transmitting end sends the uplink and downlink optical carrier signals after the optical wavelength division multiplexing to the receiving end. Step 63: At the receiving end, a pair of optical add/drop multiplexers (OADMs) in the base station (BS) selects

In (EAT), for example, the first base station selects a pair of downlink/uplink optical carriers with a wavelength of ^.

Step 64: The optical transceiver performs photoelectric conversion on the modulated optical wave to implement demultiplexing of multiple different frequency subcarriers modulated onto the optical carrier of the wavelength, and each is amplified by an amplifier (the arrow in FIG. 7 indicates the downlink RF/millimeter wave signal) is radiated by the antenna. At the same time, the uplink data received by the base station (such as the uplink RF/millimeter wave signal indicated by the unfilled arrow in FIG. 7) is modulated by the unmodulated upstream optical carrier number, and then re-entered through the optical add/drop multiplexer. The ring optical network is sent back to the central station. That is, the optical transceiver has a dual role of downlink demodulation and uplink modulation. .

The optical transceiver in the base station may be an electric absorption type optical transceiver or may be an optical modulator

An optical transceiver consisting of (sending an upstream optical carrier into the optical modulator) and a photodetector (sending a downstream optical carrier into the optical detector). The optical add/drop multiplexer may be an integrated optical add/drop multiplexer or a fiber type add/drop multiplexer.

In this embodiment, the optical add/drop multiplexing technology is adopted, and the central station can form a ring network topology structure by using a single fiber direct connection to multiple base stations, and all required light sources in the system are centrally placed in the central station, and each The base station does not need to configure the light source, which effectively controls the network construction cost. Meanwhile, if the optical transceiver in the base station is an electric absorption type optical transceiver, a modulation function of modulating the multiple subcarrier signals onto the optical carrier of a single wavelength can be realized, and the optical carrier to be modulated to a single wavelength can also be realized. The demodulation function of the subcarrier signal demultiplexing can greatly simplify the structure of the base station and reduce the construction cost.

In this embodiment, both the uplink optical carrier and the downlink optical carrier are generated by the central station, and this embodiment can also The central station generates a downlink optical carrier, and the upstream optical carrier is generated by each base station. That is, the light source generating the upstream optical carrier and the light source generating the downstream optical carrier may be disposed at the central station, or may be separately disposed at the central station and the base station.

A person skilled in the art can understand that all or part of the steps of implementing the above method embodiments may be completed by using hardware related to program instructions, and the foregoing program may be stored in a computer readable storage medium, and the program is executed when executed. The foregoing storage medium includes: ROM, RAM, magnetic disk or optical disk, and the like, which can store program codes, FIG. 8 is a schematic structural diagram of a central station according to a fifth embodiment of the present invention, including Module 81 and transmitting module 82 are used. The multiplexing module 81 is configured to perform multiplexing processing on the subcarrier signals carrying the communication data, and the transmitting module 82 is configured to transmit the multiplexed subcarrier signals.

The multiplexing module 81 may include an electrical modulator and an optical modulator/direct modulation laser; the electrical modulator is configured to separately modulate communication data of each channel on a corresponding subcarrier to obtain each corresponding subcarrier signal; A light modulator/direct modulation laser is used to modulate each subcarrier signal onto a single wavelength optical carrier; or

The multiplexing module 81 may include an electric modulator, a light modulator/direct modulation laser, and an optical wavelength division multiplexer; the electrical modulator is configured to separately modulate communication data of each channel on corresponding subcarriers to obtain respective corresponding pairs. a carrier signal; the optical modulator/direct modulation laser is configured to modulate each subcarrier signal onto an optical carrier of a different wavelength to obtain each corresponding optical carrier signal; and the optical wavelength division multiplexer is configured to perform each optical carrier signal Optical wavelength division multiplexing; or

The multiplexing module 81 may include an electric modulator, a light modulator/direct modulation laser, and an optical wavelength division multiplexer; the electrical modulator is configured to separately modulate communication data of each channel on corresponding subcarriers to obtain respective corresponding pairs. a carrier signal; the optical modulator/direct modulation laser is configured to modulate each subcarrier signal onto a downlink optical carrier of a different wavelength to obtain each corresponding downlink optical carrier signal; and the optical wavelength division multiplexer is configured to use the uplink optical carrier And performing optical wavelength division multiplexing processing on the downlink optical carrier signal.

By multiplexing the subcarrier signals in this embodiment, the capacity of the system can be increased. FIG. 9 is a schematic structural diagram of a base station according to a sixth embodiment of the present invention, including a demodulation module 91 and a demultiplexing module 92. The demodulation module 91 is configured to demodulate the optical carrier signal carrying the subcarrier signal to obtain a multiplexed subcarrier signal; the demultiplexing module 92 is configured to demultiplex the multiplexed subcarrier signal to obtain each subcarrier signal. . The demodulation module 91 demodulates the optical carrier signal carrying the subcarrier signal, which may be: Demodulating a single wavelength optical carrier signal carrying the subcarrier signal.

Or the base station further includes an optical add/drop multiplexer, configured to receive an optical carrier signal corresponding to the base station after the optical wavelength division multiplexing, where the optical carrier signal includes a downlink optical carrier signal, and the downlink optical carrier signal is sent Give the demodulation module. The optical carrier received by the optical add/drop multiplexer further includes an uplink optical carrier, or the base station further includes an optical carrier generating module, where the optical carrier generating module is configured to generate an uplink optical carrier, and the base station further includes a modulation module. The modulation module is configured to modulate the received uplink data onto the received or generated uplink optical carrier, and transmit the optical data by using the optical add/drop multiplexer.

Alternatively, the above-described demodulation module and modulation module are replaced by an optical transceiver, and the optical transceiver performs dual functions of demodulation and modulation according to downlink/uplink.

According to this embodiment, the multiplexed signal transmitted by the central station can be demultiplexed and demodulated correctly to obtain a signal corresponding to the base station.

FIG. 10 is a schematic structural diagram of a system according to a seventh embodiment of the present invention, including a first central station 101 and a first base station 102. The first central station 101 is configured to separately modulate communication data of each channel on corresponding subcarriers, obtain corresponding subcarrier signals, and modulate each subcarrier signal onto an optical carrier of a single wavelength to obtain an optical carrier signal. A base station 102 corresponds to the optical carrier of the single wavelength, and is configured to perform optical electrolytic modulation and subcarrier demultiplexing processing on the optical carrier signal. Specifically, the first central station 101 includes an electrical modulator and an optical modulator/direct modulation laser; the first base station 102 includes a photodetector and a filter. The first central station 101 is provided with a downlink optical carrier generating module for generating the optical carrier modulated with the subcarrier signal. Further, the first central station 101 may further be configured with an uplink optical carrier generating module for generating an uplink optical carrier, and the first central station 101 simultaneously sends the uplink optical carrier and the optical carrier modulated with the subcarrier signal to the optical carrier. a base station 102; Alternatively, the first base station 102 sets the uplink optical carrier generating module for generating an uplink optical carrier; the first base station 102 modulates the received uplink data to the received or self-generated uplink optical carrier, and then sends the uplink data to the first central station. 101.

In this embodiment, by implementing subcarrier multiplexing by the first central station, the number of subcarrier signals transmitted to the first base station can be increased, and the capacity between the first central station and the first base station can be improved.

Figure 11 is a block diagram showing the structure of a system according to an eighth embodiment of the present invention, including a second central station 111, a light wave splitting multiplexer 112, and a second base station 113. The second central station 111 is configured to separately modulate the communication data of each channel on the corresponding subcarriers to obtain corresponding subcarrier signals; and respectively modulate each subcarrier signal to a downlink optical carrier of a different wavelength to obtain each corresponding a downlink optical carrier signal; performing optical wavelength division multiplexing processing on each downlink optical carrier signal to obtain a multiplexed optical carrier signal; and the optical wave decomposition multiplexer 112 is configured to perform demultiplexing processing on the multiplexed optical carrier signal Obtaining each downlink optical carrier signal; the second base station 113 is at least one, corresponding to each downlink optical carrier signal, configured to perform optical electrolytic modulation and subcarrier demultiplexing processing on the corresponding downlink optical carrier signal; The carrier modulates the received uplink data onto the uplink optical carrier.

Or the second central station 111 is further configured to generate an uplink optical carrier that is paired with the downlink optical carrier, and simultaneously perform optical wavelength division multiplexing processing on the uplink optical carrier and the downlink optical carrier signal; the optical wave decomposition multiplexer 112 The pair of uplink optical carriers and the downlink optical carrier signals are obtained by demultiplexing the optical carriers, and the second base station 113 is corresponding to each pair of uplink optical carriers and downlink optical carrier signals, and is used for corresponding downlink optical signals. The carrier signal performs optical electrolytic modulation and subcarrier demultiplexing, and modulates the received uplink data onto the uplink optical carrier.

Specifically, the second central station 111 includes an electrical modulator, a light modulator/direct modulation laser, and an optical wavelength division multiplexer and a downlink optical carrier generation module; the second base station 113 includes a photodetector, a filter, and an uplink. Optical carrier generation module. Alternatively, the second central station 111 includes an electrical modulator, a light modulator/direct modulation laser and an optical wavelength division multiplexer, and a downlink optical carrier generation module and an uplink optical carrier generation module; the second base station 113 includes a photodetector And filters.

This embodiment can implement subcarrier multiplexing and optical wavelength division multiplexing, and can be demultiplexed by optical wave decomposition. The device implements WDM. The light source of the upstream optical carrier may be set in the central station or may be disposed in the base station.

Figure 12 is a block diagram showing the structure of a system according to a ninth embodiment of the present invention, including a third central station 121 and a third base station 122. The third central station 121 is configured to separately modulate the communication data of each channel on the corresponding subcarriers to obtain corresponding subcarrier signals; and respectively modulate each subcarrier signal to a downlink optical carrier of a different wavelength to obtain each corresponding a downlink optical carrier signal; performing optical wavelength division multiplexing processing on the generated uplink optical carrier and each downlink optical carrier signal. The third base station 122 corresponds to the downlink optical carrier, and is configured to perform optical add/drop multiplexing, optical electrolytic modulation, and subcarrier demultiplexing processing on the downlink optical carrier signal. The uplink data is modulated onto the upstream optical carrier.

Or the third central station 121 is further configured to generate an uplink optical carrier that is paired with the downlink optical carrier, and perform optical wavelength division multiplexing processing on the uplink optical carrier and the downlink optical carrier signal simultaneously; After the received uplink optical carrier is modulated with the uplink data, the optical wavelength division multiplexing process is performed.

Specifically, the third central station 121 includes an electrical modulator, a light modulator/direct modulation laser, and an optical wavelength division multiplexer and a downlink optical carrier generation module. The third base station 122 includes an optical add/drop multiplexer and light. Transceiver and filter and upstream optical carrier generation module. Alternatively, the third central station 121 includes an electrical modulator, a light modulator/direct modulation laser and an optical wavelength division multiplexer, and a downlink optical carrier generation module and an uplink optical carrier generation module; the third base station 122 includes optical add/drop. Multiplexers, optical transceivers, and filters.

In this embodiment, subcarrier multiplexing, optical wavelength division multiplexing, and optical add/drop multiplexing can be implemented, and the wavelength division multiplexing can be implemented by the optical add/drop multiplexer. The light source of the upstream optical carrier can be set in the central station or in the base station.

The embodiment of the present invention can increase the capacity by using the multiplexing technology, improve the utilization efficiency of the transmitting end and the receiving end, and reduce the construction cost.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than The present invention has been described in detail with reference to the preferred embodiments. It will be understood by those skilled in the art that the invention may still be modified or substituted, and the modifications or equivalents may not be modified. The latter technical solution departs from the "God and scope" of the technical solution of the present invention.

Claims

Rights request

A signal processing method, comprising:

Performing multiplexing processing on subcarrier signals carrying communication data;

The multiplexed subcarrier signal is transmitted.

2. The method according to claim 1, wherein the multiplexing processing the subcarrier signal carrying the communication data comprises:

The communication data of each channel is separately modulated on the corresponding subcarrier to obtain a corresponding subcarrier signal; each subcarrier signal is modulated onto an optical carrier of a single wavelength to obtain a multiplexed optical carrier carried on a single wavelength optical carrier. Subcarrier signal; or,

The communication data of each channel is separately modulated on the corresponding subcarriers to obtain corresponding subcarrier signals; each subcarrier signal is separately modulated onto a downlink optical carrier of a different wavelength corresponding to different base stations, to obtain corresponding downlink optical carriers. a signal; performing wavelength division multiplexing processing on each downlink optical carrier signal to obtain a multiplexed subcarrier signal; or

The communication data of each channel is separately modulated on the corresponding subcarriers to obtain corresponding subcarrier signals; the paired uplink optical carrier and the downlink optical carrier are determined; and each subcarrier signal is separately modulated to different wavelengths corresponding to different base stations. Each downlink optical carrier signal is obtained on the downlink optical carrier, and each of the uplink optical carrier and each downlink optical carrier signal is subjected to optical wavelength division multiplexing processing to obtain a multiplexed subcarrier signal.

3. A signal processing method, comprising:

The method according to claim 3, wherein the demodulating the optical carrier signal carrying the subcarrier signal comprises: demodulating a single wavelength optical carrier signal carrying the subcarrier signal.

5. The method according to claim 3, further comprising:

Receiving the optical carrier signal directly sent by the central station; or Receiving, by the central station, the optical carrier signal sent by the optical decomposition multiplexer; or receiving the optical carrier signal sent by the central station through the optical add/drop multiplexer.

The method according to claim 5, wherein the optical carrier signal sent by the receiving central station through the optical demultiplexing multiplexer comprises:

The optical wave decomposition multiplexer receives the multiplexed optical carrier signal sent by the central station, and the multiplexed optical carrier signal is composed of a downlink optical carrier signal corresponding to each base station;

Demultiplexing the multiplexed optical carrier signal by the optical wave decomposition multiplexer to obtain a downlink optical carrier signal corresponding to each base station;

The optical wave demultiplexer transmits the downlink optical carrier signals corresponding to the respective base stations to the corresponding base station.

The optical wave demultiplexer receives the multiplexed optical carrier signal sent by the central station, and the multiplexed optical carrier signal is composed of a pair of uplink optical carriers and downlink optical carrier signals corresponding to the base stations;

The optical wave decomposition multiplexer demultiplexes the multiplexed optical carrier signals to obtain a pair of uplink optical carriers and downlink optical carrier signals corresponding to the base stations;

The optical wave demultiplexer transmits the pair of uplink optical carriers and downlink optical carrier signals corresponding to the respective base stations to the corresponding base stations.

The method according to claim 5, wherein the optical carrier signal sent by the receiving central station through the optical add/drop multiplexer comprises:

The optical add/drop multiplexer in the base station receives the multiplexed optical carrier signal sent by the central station, and the multiplexed optical carrier signal is composed of downlink optical carrier signals corresponding to the base stations;

Demultiplexing the multiplexed optical carrier signal by the optical add/drop multiplexer to obtain a downlink optical carrier signal corresponding to the base station;

The optical add/drop multiplexer transmits the downlink optical carrier signal corresponding to the base station to the photodetector in the base station.

The optical add/drop multiplexer in the base station receives the multiplexed optical carrier signal sent by the central station, and the multiplexed optical carrier signal is composed of a pair of uplink optical carriers and downlink optical carrier signals corresponding to the base stations; Dissolving the multiplexed optical carrier signal by the optical add/drop multiplexer to obtain a pair of uplink optical carriers and downlink optical carrier signals corresponding to the base station;

The method according to claim 6 or 8, further comprising:

The base station generates an uplink optical carrier, and modulates the received uplink data to be transmitted on an uplink optical carrier generated by the base station.

The method according to claim 7 or 9, further comprising:

The base station receives the uplink data and modulates the received uplink data onto the received uplink optical carrier.

12. A central station, comprising:

13. The central station of claim 12, wherein:

The multiplexing module includes an electric modulator and an optical modulator/direct modulation laser; the electrical modulator is configured to respectively modulate communication data of each channel on corresponding subcarriers to obtain respective subcarrier signals; a direct modulation laser for modulating each subcarrier signal onto a single wavelength optical carrier to obtain a multiplexed subcarrier signal; or

The multiplexing module includes an electric modulator, a light modulator/direct modulation laser, and an optical wavelength division multiplexer; the electrical modulator is configured to separately modulate communication data of each channel on corresponding subcarriers to obtain corresponding pairs. a carrier signal; the optical modulator/direct modulation laser is configured to modulate each subcarrier signal to a downlink optical carrier of a different wavelength corresponding to different base stations, to obtain each corresponding downlink optical carrier. The optical wavelength division multiplexer is configured to perform optical wavelength division multiplexing processing on each downlink optical carrier signal to obtain a multiplexed subcarrier signal; or

The multiplexing module includes an electric modulator, a light modulator/direct modulation laser, and an optical wavelength division multiplexer; the electrical modulator is configured to separately modulate communication data of each channel on corresponding subcarriers to obtain respective corresponding pairs. a carrier signal; the optical modulator/direct modulation laser is configured to modulate each subcarrier signal to a downlink optical carrier of a different wavelength corresponding to different base stations to obtain each corresponding downlink optical carrier signal; the optical wavelength division multiplexer is used for Performing optical wavelength division multiplexing on the uplink optical carrier and the downlink optical carrier signal corresponding to the downlink optical carrier generated by the central station to obtain a multiplexed subcarrier signal.

A base station, comprising:

And a demultiplexing module, configured to demultiplex the multiplexed subcarrier signals to obtain respective subcarrier signals.

The base station according to claim 14, further comprising:

An optical add/drop multiplexer, configured to demultiplex the optical carrier signal of the optical wavelength division multiplexing transmitted by the central station, obtain a downlink optical carrier signal corresponding to the base station, and send the downlink optical carrier signal to the demodulation Module

An optical carrier generating module, configured to generate an uplink optical carrier;

And a modulation module, configured to receive uplink data, and modulate the uplink data onto the generated uplink optical carrier, and send the optical data through the optical add/drop multiplexer.

The base station according to claim 14, further comprising:

The optical add/drop multiplexer is configured to demultiplex the optical carrier signal of the optical wavelength division multiplexing transmitted by the central station, obtain an uplink optical carrier and a downlink optical carrier signal corresponding to the base station, and send the downlink optical carrier signal to The demodulation module;

And a modulation module, configured to receive uplink data, and modulate the uplink data onto the obtained uplink optical carrier, and send the optical data through the optical add/drop multiplexer.

17. A network system, comprising: a first central station, configured to separately modulate communication data of each channel on a corresponding subcarrier to obtain each corresponding subcarrier signal; and modulate each subcarrier signal to an optical carrier of a single wavelength to obtain an optical carrier signal;

18. The system of claim 17 wherein:

The first central station includes an electrical modulator and a light modulator/direct modulation laser;

The first base station includes a photodetector and a filter.

19. A network system, comprising:

a light wave decomposition multiplexer, configured to demultiplex the multiplexed optical carrier signal to obtain each downlink optical carrier signal;

20. The system of claim 19, wherein:

The second central station is further configured to generate an uplink optical carrier that is paired with the downlink optical carrier, and simultaneously perform optical wavelength division multiplexing processing on the uplink optical carrier and the downlink optical carrier signal;

The optical wave decomposition multiplexer is configured to demultiplex the optical carrier to obtain each pair of uplink optical carriers and downlink optical carrier signals;

Corresponding to the pair of uplink optical carriers and downlink optical carrier signals, the second base station is configured to perform optical electrolytic modulation and subcarrier demultiplexing on the corresponding downlink optical carrier signals, and modulate the received uplink data to the uplink optical carrier. on.

21. The system of claim 19, wherein: The second central station includes an electrical modulator, a light modulator/direct modulation laser, and an optical wavelength division multiplexer and a downlink optical carrier generation module; the second base station includes a photodetector and a filter and an uplink optical carrier generation module.

22. The system of claim 20, wherein:

The second central station includes an electric modulator, an optical modulator/direct modulation laser, and an optical wavelength division multiplexer, and a downlink optical carrier generation module and an uplink optical carrier generation module;

The second base station includes a photodetector and a filter.

23. A network system, comprising:

24. The system of claim 23, wherein:

The third central station is further configured to generate an uplink optical carrier that is paired with the downlink optical carrier, and simultaneously perform optical wavelength division multiplexing processing on the uplink optical carrier and the downlink optical carrier signal;

The third base station is further configured to perform modulation on the received or generated uplink optical carrier by using the uplink data and performing optical wavelength division multiplexing processing.

25. The system of claim 23, wherein:

The third central station includes an electrical modulator, an optical modulator/direct modulation laser, and an optical wavelength division multiplexer and a downlink optical carrier generation module;

The third base station includes an optical add/drop multiplexer, an optical transceiver and a filter, and an upstream optical carrier generating module.

26. The system of claim 24, wherein:

The third central station includes an electrical modulator, a light modulator/direct modulation laser, and optical wavelength division multiplexing And a downlink optical carrier generating module and an uplink optical carrier generating module; the third base station includes an optical add/drop multiplexer, an optical transceiver, and a filter.