CN101340647B - Wireless access system and carrier moving method based on centralized base station - Google Patents
Wireless access system and carrier moving method based on centralized base station Download PDFInfo
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Abstract
The invention discloses a wireless access system based on a centralized base station, which comprises a centralized base station and a remote antenna unit. The centralized base station is used for the dynamic configuration or virtual carrier frequency shifting of a carrier frequency signal, and the carrier frequency signal is modulated and multiplexed to light wave and then the light wave is multiplexed to an optical fiber link; the remote antenna unit is connected with the centralized base station by the optical fiber link as well as is used for extracting the carrier frequency signal modulated to an optical wave link and transmitting the signal to covered areas by a transmitting antenna. The invention also discloses a carrier frequency removal method based on the centralized base station. The system of the invention inherits the advantages of a distributed antenna system, enhances spectrum utilization rate and system capacity, and meanwhile realizes the functions of virtual carrier frequency removal and dynamic configuration of wireless resources.
Description
Technical field
The present invention relates to the wireless signal access technology in a kind of wireless communication field, specifically, relate to a kind of wireless access system and carrier moving method based on the centralization base station.
Background technology
Radio communication is one of most active branch in the communications field, also is the current communication technology with fastest developing speed.The proposition of honeycomb notion makes mobile communication obtain develop rapidly, no matter is first generation analog communication system, second generation digital communication system, or the network configuration that honeycomb fashion covers has all been continued to use in third generation communication.It is that the geographic area is divided into some sub-districts that honeycomb covers, and sets up a base station and antenna (situation that a shared base station, several sub-districts and antenna are also arranged) in each sub-district and covers whole sub-district, and all users in the sub-district insert this base station.This network configuration has played certain effect to improving the availability of frequency spectrum; Its conventional method is to carry out cell splitting and cell sectorization; But this method can only be alleviated the contradiction between limited frequency spectrum, power system capacity and the increasingly high communicating requirement to a certain extent, because; Cell splitting and sectorization can not unrestrictedly go on, and this can bring a lot of problems such as interference, frequent switching.
Distributing antenna system is a kind of new Radio Access Network structure, and it separates the base station with antenna, utilize optical fiber to be sent to antenna to base station signal, is transmitted into the user then.Compare with honeycomb; This system is the extension of abundant fiber resource as radio communication, and a large amount of spaced antennas are more near the user, and it is the sub-district at center with terminal use that several strip antennas around the user are formed one; Like this; The transmitting power at antenna and terminal can reduce significantly, simultaneously, can improve the availability of frequency spectrum and power system capacity greatly.
Most signal processing is accomplished in the base station in the distributing antenna system, exists relatively-stationary relation between CF signal in the base station and the spaced antenna, and this has just weakened system to burst service peak emergency processing ability greatly.For example, in a certain zone, hold megaevent, when theatrical performances etc. were movable, traffic carrying capacity was increased sharply, and power system capacity dynamically adjustment can cause conversation loss maybe can't insert.Usually the method that solves this type problem is that certain Radio Resource is reserved in the base station, and still, this can increase the equipment investment of operator greatly.
Summary of the invention
The technical problem that the present invention solved provides a kind of wireless access system based on the centralization base station, has realized the dynamic-configuration with Radio Resource of moving of virtual carrier frequency.
Technical scheme is following:
A kind of wireless access system based on the centralization base station comprises:
The centralization base station is used for CF signal is carried out dynamic-configuration or virtual carrier frequency is moved, with said CF signal modulation be multiplexed on the light wave, and with said optical wavelength multiplexing to optical fiber link;
The far-end antenna element is connected with said centralization base station through optical fiber link, is used to extract the said CF signal that is modulated to the light wave link, arrives institute's region covered via transmission antennas transmit.
Preferably, said optical fiber link comprises the WDM looped network that is connected successively, full fiber optic ring network, OADM optical node and optical fiber branch road.
Preferably, described far-end antenna element comprises optical fiber link interface unit, radio-frequency front-end and antenna system; Said optical fiber link interface unit is used for the light wave on the optical fiber link is downloaded to RAU, and perhaps, the uplink electrical signals that RAU is received changes light signal into, sends in the optical fiber link and goes; Radio-frequency front-end is used for descending baseband signal is modulated to radiofrequency signal, perhaps up radiofrequency signal is down-converted to baseband signal and forms radiofrequency signal, and said antenna system is used for radiofrequency signal is sent.
Preferably, said centralization base station comprises:
Baseband processing unit is used for changing CF signal into intermediate frequency or radiofrequency signal, and sends;
The radio frequency cross linkage unit is used for said intermediate frequency or radiofrequency signal are routed to the sub-carrier modulation unit;
The sub-carrier modulation unit is used to make the frequency of said intermediate frequency or radiofrequency signal to produce shift frequency formation modulating frequency, and said modulating frequency is multiplexed on one tunnel optical wavelength, and modulated process receives the frequency shift keying unit monitors;
Optical cross-connection unit is used for optical wavelength is routed to the wavelength division multiplexing unit;
The wavelength division multiplexing unit is used to accomplish optical wavelength and arrives the multiplexing of said optical fiber link;
The control maintenance unit is used for administering and maintaining of system, and each module is carried out associated treatment when being used for virtual carrier frequency and moving;
The frequency shift keying unit is used to detect the accuracy of sub-carrier modulation cells modulate.
Preferably, said frequency shift keying unit receives the frequency modulation information of sub-carrier modulation unit described in the said control maintenance unit; Said frequency shift keying unit detects the carrier wave frequency information after the sub-carrier modulation cells modulate; Modulation intelligence contrast with the sub-carrier modulation unit in itself and the said control maintenance unit; Both are consistent to explain that the SCM modulation is correct, otherwise, both explain that the carrier frequency after the SCM modulation exists mistake or error.
Preferably, said baseband processing unit comprises baseband pool, and dynamically is connected with said radio frequency cross linkage unit.
Preferably, said sub-carrier modulation unit has at least one optical wavelength input port and at least one optical wavelength output port; Described radio frequency cross linkage unit is used to accomplish the interconnection of said intermediate frequency or radiofrequency signal, CF signal is routed on the different optical wavelength input ports of said sub-carrier modulation unit; Described sub-carrier modulation unit is used for modulation behind the CF signal shift frequency and is multiplexed into one tunnel optical wavelength, and sends through different optical wavelength output ports.
Preferably, said optical cross-connection unit is routed to different wavelength division multiplexing unit according to service needed with different optical wavelength, realizes the dynamic assignment of optical wavelength.
Another technical problem that the present invention solved provides a kind of carrier moving method based on the centralization base station, has realized the dynamic-configuration with Radio Resource of moving of virtual carrier frequency.
Technical scheme is following:
A kind of carrier moving method based on the centralization base station comprises:
(1) dynamic-configuration is carried out with CF signal or virtual carrier frequency is moved in the centralization base station, then with the modulation of the CF signal behind the said shift frequency be multiplexed on the light wave, and is routed to different far-end antenna elements;
(2) said far-end antenna element extracts and is modulated to the said CF signal on the light wave, arrives institute's region covered via transmission antennas transmit.
Further; In the step (1), when virtual carrier frequency is moved, adopt and close on principle, said close on pay the utmost attention in the principle move sub-carrier modulation after the close CF signal of frequency; Consider to move the CF signal that closes on the optical wavelength then, consider to move the CF signal that closes on the optical fiber link at last.
Further, in the step (1), the step that said virtual carrier frequency is moved comprises:
(11) the mapping relation table is carried out initialization and renewal;
(12) mapping relations of change CF signal and subcarrier shift frequency frequency make said CF signal produce shift frequency and form modulating frequency, and on the road optical wavelength that said modulating frequency modulation is also multiplexing; In shift frequency, modulation and multiplex process, observe said mapping relations table;
(13) with said optical wavelength multiplexing to optical fiber link, in multiplex process, observe the said relation table of penetrating.
Further, in the step (11), the said relation table of penetrating comprises CF signal tabulation, shift frequency list of frequency, modulating frequency tabulation, optical wavelength tabulation, the tabulation of interconnection optical wavelength, wavelength division multiplexing tabulation, optical fiber link tabulation.
Further, in the step (11), when disposing said mapping relations table, avoid carrying on the optical wavelength two or more, perhaps avoid on an optical fiber, carrying two or more identical optical wavelength with wireless carrier signal frequently.
Further, in the step (12), the radio frequency cross linkage unit is routed to the sub-carrier modulation unit through calling said CF signal tabulation with said CF signal; The said shift frequency list of frequency of sub-carrier modulation cell call, modulating frequency tabulation and optical wavelength tabulation with the shift frequency frequency effect in said CF signal and the sub-carrier modulation unit, produce modulating frequency, then this modulating frequency are modulated and are multiplexed on the optical wavelength; In the step (13), optical cross-connection unit calls the tabulation of interconnection optical wavelength, and the optical wavelength of carrying CF signal is carried out the interconnection of optical wavelength, and sends; Wavelength division multiplexing cell call wavelength division multiplexing tabulation, with said optical wavelength multiplexing to optical fiber link.
The proposition that the present invention proposes has been inherited the advantage of distributing antenna system based on the wireless access system of centralization base station, has improved the availability of frequency spectrum and power system capacity, simultaneously, has realized that virtual carrier frequency moves the function with the Radio Resource dynamic-configuration.All carrier frequency resources have been concentrated in the centralization base station; Base band signal process and most of radio frequency processing are all accomplished in the centralization base station; Radio frequency cross linkage unit, sub-carrier modulation unit, optical cross-connection unit and WDM unit are accomplished modulation, CF signal route and the light wave routing function of CF signal to light wave; Realized not changing under the situation of centralization BTS hardware, according to business demand dynamic-configuration carrier frequency and adjustment Radio Resource.
Radio frequency cross linkage unit, sub-carrier modulation unit, optical cross-connection unit have been accomplished the routing function of CF signal to different far-end antenna elements; Realized that virtual carrier frequency moves and the Radio Resource dynamic-configuration, can solve the demand of burst peak business network.Realize the optimization that Internet resources dispose based on the wireless access system of centralization base station, reduced the equipment investment of operator.Because virtual carrier moving function, the carrier frequency of whole network need not dispose by maximum telephone traffic, and only need dispose by average telephone traffic, thereby reduces investment outlay greatly.In addition,, strengthened system robustness, can realize non-maintainingly, saved maintenance cost because far-end antenna element equipment simplifies greatly.
In the wireless access system based on the centralization base station, the centralization base station maintenance is easy, dilatation convenient; The WDM fiber optic network is safe and reliable, and frequency resource is abundant; Far-end antenna element hardware device is simple, easy mounting, robustness are good, can realize non-maintaining.Virtual carrier frequency is moved the investment that technology is saved operator greatly, and whole system can be carried the wireless access system of multiple standard, like GSM, and CDMA, UMTS, BWA, WiMAX and WLAN etc.
Description of drawings
Fig. 1 is based on the schematic network structure of the wireless access system of centralization base station;
Fig. 2 is a centralization base station logic module structure sketch map;
Fig. 3 is a far-end antenna unit structure sketch map;
Fig. 4 is a centralization base station system structure chart;
Fig. 5 is that centralization base station virtual carrier frequency is moved sketch map.
Embodiment
The wireless access system based on the centralization base station that the present invention proposes has been inherited the advantage of distributing antenna system, improves the availability of frequency spectrum and power system capacity, simultaneously, has realized that virtual carrier frequency moves the function with the Radio Resource dynamic-configuration.
In the metropolitan area scope, only establish a big capacity centralization base station (CB based on the wireless access system of centralization base station; Centralized BTS) and some far-end antenna element (RAU; Remote AntennaUnit); Both are connected through optical fiber, form a metropolitan area antenna distributed network (DAN, Distributed Antenna Network) jointly.The centralization base station is sent to distributed far-end antenna element to intermediate frequency or radiofrequency signal through optical fiber, and the sky bundle of lines CF signal through the far-end antenna element is transmitted into the overlay area again.(CB) concentrated all carrier frequency resources in the centralization base station; Base band signal process and most of radio frequency processing are all accomplished in the centralization base station; Through CF signal being arrived modulation, CF signal route and the light wave routing function of light wave; Realized that virtual carrier frequency moves and the Radio Resource dynamic-configuration, solved the demand of burst peak business network.
With reference to the accompanying drawings, the preferred embodiments of the present invention are described in detail.
As shown in Figure 1; In a bigger geographic area or metropolitan area scope; Wireless access system based on the centralization base station comprises a centralization base station (CB; Centralized BTS) and some far-end antenna elements, be connected through optical fiber link between CB and the RAU, form distributed metropolitan area aerial network.Optical fiber link comprises WDM looped network (WDM all fiber ring), full fiber optic ring network, OADM (optical add-drop multiplexer) optical node and optical fiber branch road.The far-end antenna element is through the optical wavelength on the optical fiber link at optical interface (selecting FC for use at this optical interface) download OADM node place; Carry out opto-electronic conversion; Then; Extract through band pass filter and to be modulated to the CF signal on the light wave, and carry out processing such as frequency conversion, accomplish the emission of CF signal at last through antenna.Up direction, the signal of RAU receiving terminal after down-conversion and filtering, is a light signal with conversion of signals, amplifying through EDFA, is transferred among the CB through optical fiber link, carries out processing such as demodulation.
At down direction, the optical fiber link interface unit is downloaded certain or some optical wavelength from optical fiber link, and changes light signal into the signal of telecommunication through PD (photodiode).Band pass filter BPF leaches the carrier signal that RAU needs from the signal of telecommunication, pass through the upconversion process of frequency mixer and the processing and amplifying of power amplifier then, launches from antenna; Up direction; RAU receives wireless signal from antenna, after amplifying through low noise amplifier, carries through the tuning Filtering Processing of selecting ripple and band pass filter of frequency mixer; Obtain up rf signal; LD (laser diode) changes the signal of telecommunication into light signal, and is modulated on the light wave, sends to CB through optical fiber link at last.
RAU is simple in structure, and radio-frequency front-end is only relevant with frequency with antenna system, therefore, adopts different radio frequency front end and antenna system just can support the different radio standard, like GSM, CDMA, UMTS, WLAN, BWA, WiMAX etc.Adopt the radio-frequency front-end and the antenna system in broadband can support multiple wireless standard simultaneously.
In traditional cellular network architecture, one or several sub-district is responsible in a base station, needs a plurality of base stations to accomplish comprehensively in the metropolitan area scope or in the bigger geographic area and covers.By comparison, the centralization base station is equivalent to all base station resources are concentrated in together, and forms a jumbo base station, and the far-end antenna element is responsible for covering a little zone, and a plurality of far-end antenna elements form distributed overlay network.The far-end antenna element is connected to the centralization base station through the WDM optical networking, downloads different optical wavelength at optical network node OADM place, distributes through optical fiber Zhi Luxiang far-end antenna element then to be carried on the wireless carrier signal on this wavelength.
Down direction, all CF signals send by a centralization base station, are sent to described far-end antenna element through optical fiber, the far-end antenna element with the signal demodulation after, to the institute overlay area, the up direction process is in contrast via transmission antennas transmit.
As shown in Figure 2; Centralization base station (CB) mainly comprise baseband processing unit (BBU; BaseBand Unit), radio frequency cross linkage unit (RXC, Radio Cross-Connection), sub-carrier modulation unit (SCM, Sub-Carrier Multiplexing), optical cross-connection unit (OXC; OpticalCross-Connection), wavelength division multiplexing unit (WDM; Wavelength DivisionMultiplexing), control maintenance unit (CMM, Control Maintenance Module), frequency shift keying unit (FSK, Frequency Shift key).
FSK mainly is responsible for the monitoring work of SCM modulation, and CMM is the frequency modulation information of SCM, and for example the frequency bandwidth of the frequency of carrier wave, adjacent carrier etc. sends to FSK; FSK detects the carrier wave frequency information after the modulation, and with its SCM modulation intelligence contrast with CMM, both consistent SCM that explain modulate correctly, otherwise, explain that the carrier frequency after SCM modulates exists mistake or error.Can monitor the accuracy of SCM modulation through FSK.
Wherein, baseband processing unit (BBU, Base Band Unit) is mainly used in Base-Band Processing and the part radio frequency processing of accomplishing all CF signals, comprises baseband processing module and radio frequency processing module.Baseband processing module is with the work of resource sharing mode, and promptly baseband processing module forms a resource pool, dynamically is connected with the radio frequency processing module, and from baseband processing unit output is analog intermediate frequency or radiofrequency signal.It is that baseband signal with descending is modulated to radiofrequency signal that the radio frequency processing module mainly acts on, and perhaps up radiofrequency signal is down-converted to baseband signal.
Radio frequency cross linkage unit (RXC, Radio Cross-Connection) is accomplished analog intermediate frequency or the radiofrequency signal routing function to sub-carrier modulation unit (SCM).Sub-carrier modulation unit (SCM) comprises shift frequency module, modulation and Multiplexing module, and wherein, the effect of shift frequency module is to make the CF signal frequency of input produce shift frequency, has the local modulating frequency that is no less than the CF signal number; Modulation and Multiplexing module are modulated to one or more CF signal through shift frequency on the optical wavelength, and modulated process is monitored by FSK.Optical cross-connection unit (OXC, Optical Cross-Connection) is accomplished the cross connect function of different optical wavelength to the WDM unit.The multiplexing function of optical wavelength to optical fiber link accomplished in wavelength division multiplexing unit (WDM, Wavelength DivisionMultiplexing).
Control maintenance unit (CMM, Control Maintenance Module) is responsible for administering and maintaining of CB system, to each module be configured, monitoring, troubleshooting etc.The associated treatment of each module when particularly being responsible for virtual carrier frequency and moving, for example cross interconnected, the SCM modulation management of radiofrequency signal, light Cross module wavelength routing management etc.
The interconnection, radiofrequency signal frequency displacement processing, frequency-shift signaling that exist radiofrequency signal in CB inside are to the modulation multiplex of light wave, the various procedures such as interconnection of light signal.For reasonable disposition and management CB, at CMM or based on the network management system stored mapping relations table T of centralization base station access network, this is penetrated relation table T and comprises following parameter list:
CF signal tabulation S
n, CF signal is meant the analog intermediate frequency or the radiofrequency signal of BBU output, n is the CF signal sequence number;
The shift frequency list of frequency f of sub-carrier modulation unit
n, the shift frequency frequency makes CF signal generation frequency displacement, obtains the sub-carrier modulation list of frequency, and n is the sequence number of shift frequency frequency;
The modulating frequency tabulation f of sub-carrier modulation unit
Sn, f
SnWith f
nCorresponding one by one, sn is the sequence number of modulating frequency;
Optical wavelength tabulation λ
m, m is the sequence number of optical wavelength;
Interconnection optical wavelength tabulation λ
Sm, be light wavelength lambda
mThrough the light wave of exporting behind the optical cross-connection unit, sm is the optical wavelength sequence number;
The WDM WDM that tabulates
l, l is the sequence number of WDM unit;
Optical fiber link tabulation L
k, k is the optical fiber link sequence number, the WDM unit is corresponding one by one with optical fiber link;
The far-end antenna element ID R that tabulates
p, p is far-end antenna element ID number, there is the relation that is fixedly connected in the far-end antenna element with optical fiber link.
The mapping relations table T of parameter list has reflected the radio-resource-configuration situation of centralization base station access system.It has comprised S
nIn CF signal to f
nThe routing relation of middle shift frequency frequency, f
SnTo λ
mModulation and multiplexing relation, λ
mTo λ
SmInterconnection relation, λ
SmTo WDM
lMultiplexing relation, WDM
lWith L
kCorresponding relation, optical fiber link L
kTo far-end antenna element R
pAnnexation.Mapping relations table T has finally set up the radio carrier frequency signal to far-end antenna element mapping relations.
During the configuration mapping relation table, must avoid two kinds of situation: carry two or more on the first, one optical wavelength with the frequency wireless carrier signal; The second, be on an optical fiber, to carry two or more identical optical wavelength.In order to reach this purpose; Taked validity checking mechanism based on the wireless access system of centralization base station, before configuration or upgrading mapping relations table T, the mapping relation table has been examined by CMM or network management system; One of above-mentioned two kinds of situation occurring is regarded as illegally forbidding resource distribution.
In the wireless access system based on the centralization base station, the CF signal emission receives and virtual carrier frequency is moved through following process realization:
The radio frequency cross linkage unit is through calling CF signal tabulation S
n, CF signal is routed to the sub-carrier modulation unit; Sub-carrier modulation cell call shift frequency list of frequency f
n, modulating frequency tabulation f
SnWith optical wavelength tabulation λ
m, with CF signal S
nWith the shift frequency frequency f in the sub-carrier modulation unit
nEffect produces modulating frequency f
Sn, modulate and be multiplexed into light wavelength lambda then
mOn.Subcarrier shift frequency list of frequency f
nIn the frequency number be no less than CF signal tabulation S
nIn the CF signal number, f
nIn frequency have nothing in common with each other, purpose is to guarantee the modulating frequency f that produces after both mixing
SnHave nothing in common with each other.Subcarrier is to the multiplexing CF signal tabulation S that meets of light wave
nTo optical wavelength tabulation λ
mMapping relations.Through software control CF signal is multiplexed on the different optical wavelength, thereby realizes that CF signal is carrying moving on the optical wavelength.
Optical cross-connection unit calls interconnection optical wavelength tabulation λ
Sm, with the light wavelength lambda of carrying CF signal
mCarry out the interconnection of optical wavelength, output light wavelength λ
SmThe wavelength division multiplexing cell call WDM WDM that tabulates
l, with λ
SmBe multiplexed into WDM
iOn the unit, WDM
iThe unit is connected to optical fiber link L
kOn.Can make the optical wavelength multiplexing that is carrying CF signal through software control to different WDM unit, thereby realize optical wavelength moving at optical fiber link.
Optical fiber link L
kWith far-end antenna element R
pExist to be fixedly coupled relation, optical fiber link comprises the full fiber optic ring network of WDM, OADM optical node and optical fiber branch road (Fig. 1).The far-end antenna element is through downloading optical fiber link L at OADM node place
kOn light wavelength lambda
Sm, perhaps download light wavelength lambda through amplifying through optical interface (FC)
Sm, carry out opto-electronic conversion, then, extract through band pass filter and to be modulated to the CF signal on the light wave, and carry out processing such as frequency conversion, accomplish the emission of CF signal at last through antenna.
In whole process, the interconnection of the interconnection of CF signal, frequency conversion, sub-carrier modulation, light signal and the multiplexing parameter maps relation table T that strictly observes are to guarantee the correctness of radio carrier frequency signal transmitting and receiving and carrier moving.Pass through said process; Centralization base station radio connecting system can be accomplished CF signal and focus on and distributed emission, the more important thing is, under the condition that does not change Hardware configuration; The realization virtual carrier frequency is moved, and makes the wireless access system based on the centralization base station become dynamic distributed system.
In addition; For of the requirement of reduction system, particularly reduce the performance requirement of OADM in far-end antenna element median filter and the WDM looped network, when virtual carrier frequency is moved to the technical sophistication degree of equipment; Employing closes on principle; Promptly pay the utmost attention to and move the close CF signal of frequency after the sub-carrier modulation, consider to move the CF signal that closes on the optical wavelength then, consider to move the CF signal that closes on the optical fiber link at last.
As shown in Figure 3, the far-end antenna element is mainly used in completion light/electricity conversion (PD, Photo Detector)/(LD, Laser Diode), mainly comprises optical fiber link interface unit, radio-frequency front-end and antenna system (Antenna) etc.The optical fiber link interface unit is responsible for the light wave on the optical fiber link is downloaded to RAU, and perhaps, the uplink electrical signals that RAU is received changes light signal into, sends in the optical fiber link and goes.The optical fiber link interface unit comprises optical circulator, photodiode (PD), laser diode (LD), fiber amplifier devices such as (EDFA).Radio-frequency front-end is used for descending baseband signal is modulated to radiofrequency signal, perhaps up radiofrequency signal is down-converted to baseband signal, comprises filter (BPF), frequency mixer, power amplifier (PA), low noise amplifier (LNA) etc.Antenna system is used for sending or received RF signal.
In order to save optical fiber link, to avoid producing than long time delay between the CF signal transmitting-receiving, centralization base station and far-end antenna element all utilize optical circulator that the receiving and transmitting signal of one road carrier frequency is multiplexed on the optical fiber link.
With reference to shown in Figure 4, the system configuration and the handling process of CF signal in center base station of centralization base station are described in detail.
The inner resource pool that forms a completion Base-Band Processing of baseband processing unit (BBU), the dynamic process CF signal, from baseband processing unit (BBU) output is analog intermediate frequency or radio frequency (IF/RF) signal.The IF/RF signal is input to the RXC unit, and the IF/RF signal can be routed to different output ports from input port in RXC.Then, the IF/RF signal gets into the SCM unit, and local shift frequency frequency is carried out the shift frequency processing to CF signal in the SCM; Obtain the SCM modulating frequency, then, with the CF signal modulation multiplex behind the shift frequency on optical wavelength; Can the right demodulation CF signal in order to ensure the far-end antenna element; Here need guarantee that the modulating frequency that is carried on the same wavelength has nothing in common with each other, comprise photodiode (PD, Photo Detector), laser diode (LD in the SCM unit; Laser Diode), descending pass port filter (PFDL, pass filter of downlink).Lightwave signal gets into the OXC unit, and in the OXC unit, optical wavelength is carried out interconnection, and purpose is that every road optical wavelength can both be exported from the different output ports of OXC.The OXC output port directly is connected with WDM, and WDM to optical fiber link, sends to the far-end antenna element to the optical wavelength multiplexing of input after light amplification.In OXC and WDM unit, must guarantee two-way and optical wavelength identical more than the two-way to occur in the optical fiber link.Signal processing recited above is accomplished under the CMM unit monitors, and satisfies the legitimacy requirement of parameter maps relation table T.
In order to realize that one road signal transmitting and receiving realizes in an optical fiber link, add an optical circulator at the back at one group of WDM unit of being responsible for receiving and dispatching.
In the centralization base station, CF signal by frequency division multiplexing on optical wavelength, light wave by wavelength division multiplexing to optical fiber link.Like this, distinguish wavelength signals with tunable OADM,, realize the smooth transmission of CF signal to the far-end antenna element at the radio carrier frequency signal of remote terminal far-end antenna element through filter differentiation and download different frequency at the optical network node place.
Can realize under the hardware devices circumstances that virtual carrier frequency moves not changing based on the wireless access system of centralization base station, satisfy the professional requirement that changes radio-resource-configuration.
With reference to shown in Figure 5, the shift frequency process is described in detail.
Technical scheme of the present invention realizes virtual move of CF signal between different far-end antenna elements through the radio frequency cross linkage unit in the centralization base station, sub-carrier modulation unit, optical cross-connection unit and WDM unit under the situation that does not change the configuration of centralization BTS hardware.
When initial configuration, the centralization base station is to the CF signal S that tabulates
n, the sub-carrier modulation unit shift frequency list of frequency f
n, modulating frequency tabulation f
Sn, optical wavelength tabulation λ
m, interconnection optical wavelength tabulation λ
Sm, WDM unit tabulation WDM
l, optical fiber link tabulation L
k, far-end antenna element tabulation R
pAnd the mapping relations table T between each parameter list carries out initialization, and mapping relations table T is stored in the control maintenance unit or network management system of centralization base station.Footnote n, sn, m, l, k and the p of parameter list symbol represents parameter sequence number in the tabulation respectively, and the mapping relations table has reflected the corresponding relation of parameter between each tabulation.
Before virtual carrier frequency is moved; The control maintenance unit of centralization base station or network management system calculating are also upgraded described tabulation and mapping relations table; Assurance is avoided carrying two and plural identical subcarrier frequency on the optical wavelength, avoids carrying on the optical fiber optical wavelength identical more than two and two.Move according to new said tabulation and mapping relations table enforcement virtual carrier frequency.
CF signal S
nBe routed to the sub-carrier modulation unit through the radio frequency cross linkage unit, with the shift frequency frequency f in the sub-carrier modulation unit
nEffect produces the sub-carrier modulation frequency f
Sn, modulate and be multiplexed into light wavelength lambda then
mOn.During carrier moving, through changing CF signal S
nWith subcarrier shift frequency frequency f
nMapping relations realize CF signal moving on the different bearer optical wavelength.Carrying the light wavelength lambda of CF signal
mThrough output light wavelength behind the optical cross-connection unit is λ
Sm, λ
SmBe connected to WDM
lOn the unit, then, through WDM
lBe multiplexed into optical fiber link L
kOn.When virtual carrier frequency is moved, change light wavelength lambda through the control optical cross-connection unit
mWith λ
SmBetween interconnection relation, just can realize optical wavelength moving at optical fiber link.
Optical fiber link L
kWith far-end antenna element R
pHave corresponding relation, the far-end antenna element can be discerned and demodulation L
kOn CF signal, be transmitted into the overlay area after the processing.
Through said process, CF signal can dynamically be moved on wavelength, optical fiber link and far-end antenna element.
Be example with one road CF signal S1 below, explain that a concrete virtual carrier frequency moves process.
Before virtual carrier frequency was moved, radio carrier frequency signal S1 was transferred to ID number through path Line1 and is the far-end antenna element of R1.S1 is sent by the BBU unit, through the f of RXC elements exchange to the sub-carrier modulation unit
1Port, f
1Be the shift frequency frequency of sub-carrier modulation, S1 is through f
1Shift frequency handle after, frequency becomes f
S1, f
S1Be the modulating frequency of sub-carrier modulation unit, f
S1Radiofrequency signal is modulated onto light carrier λ
1On, λ
1Be multiplexed into WDM1 and go up, transmit far-end antenna element R1 through optical fiber link L1.Far-end antenna element R1 downloads λ through opto-electronic conversion and band pass filter
1On CF signal S1, through after the frequency conversion, be transmitted into the overlay area.
The transmission path Line1 of S1 is as follows among the mapping relations table T:
Have mapping relations between CF signal sequence number and the far-end antenna element ID number, and mapping satisfies the legitimacy requirement, this has just accomplished transmitting and receiving of CF signal.
After if virtual carrier frequency is moved, the transmission path of S1 changes Line2 into, and the parameter corresponding relation in the mapping relations table is as follows:
Radio carrier frequency signal S1 sends to far-end antenna element Ri, and mapping relations satisfy the legitimacy requirement.
CF signal S1 moves in the process, does not change the Hardware configuration of centralization base station, but has realized the migration of CF signal on different wave length and different fiber link through software control RXC, SCM and OXC.
Claims (12)
1. the wireless access system based on the centralization base station is characterized in that, comprising:
The centralization base station is used for CF signal is carried out dynamic-configuration or virtual carrier frequency is moved, with said CF signal modulation be multiplexed on the light wave, and with optical wavelength multiplexing to optical fiber link;
The far-end antenna element is connected with said centralization base station through optical fiber link, is used to extract the said CF signal that is modulated to the light wave link, arrives institute's region covered via transmission antennas transmit;
Said centralization base station comprises:
Baseband processing unit is used for changing CF signal into intermediate frequency or radiofrequency signal, and sends;
The radio frequency cross linkage unit is used for said intermediate frequency or radiofrequency signal are routed to the sub-carrier modulation unit;
The sub-carrier modulation unit is used to make the frequency of said intermediate frequency or radiofrequency signal to produce shift frequency formation modulating frequency, and said modulating frequency is multiplexed on one tunnel optical wavelength, and modulated process receives the frequency shift keying unit monitors;
Optical cross-connection unit is used for optical wavelength is routed to the wavelength division multiplexing unit;
The wavelength division multiplexing unit is used to accomplish optical wavelength and arrives the multiplexing of said optical fiber link;
The control maintenance unit is used for administering and maintaining of system, and each module is carried out associated treatment when being used for virtual carrier frequency and moving;
The frequency shift keying unit is used to detect the accuracy of sub-carrier modulation cells modulate.
2. the wireless access system based on the centralization base station according to claim 1 is characterized in that, said optical fiber link comprises the WDM looped network that is connected successively, full fiber optic ring network, OADM optical node and optical fiber branch road.
3. the wireless access system based on the centralization base station according to claim 1 is characterized in that, described far-end antenna element comprises optical fiber link interface unit, radio-frequency front-end and antenna system; Said optical fiber link interface unit is used for the light wave on the optical fiber link is downloaded to far-end antenna element RAU, and perhaps, the uplink electrical signals that RAU is received changes light signal into, sends in the optical fiber link and goes; Radio-frequency front-end is used for descending baseband signal is modulated to radiofrequency signal, perhaps up radiofrequency signal is down-converted to baseband signal, and said antenna system is used for radiofrequency signal is sent.
4. the wireless access system based on the centralization base station according to claim 1 is characterized in that, said frequency shift keying unit receives the frequency modulation information of sub-carrier modulation unit described in the said control maintenance unit; Said frequency shift keying unit detects the carrier wave frequency information after the sub-carrier modulation cells modulate; Modulation intelligence contrast with the sub-carrier modulation unit in itself and the said control maintenance unit; Both are consistent to explain that sub-carrier modulation cell S CM modulation is correct; Otherwise, explain that the carrier frequency after the SCM modulation exists mistake or error.
5. the wireless access system based on the centralization base station according to claim 1 is characterized in that said baseband processing unit comprises baseband pool, and dynamically is connected with said radio frequency cross linkage unit.
6. the wireless access system based on the centralization base station according to claim 1 is characterized in that, said sub-carrier modulation unit has at least one optical wavelength input port and at least one optical wavelength output port; Described radio frequency cross linkage unit is used to accomplish the interconnection of said intermediate frequency or radiofrequency signal, CF signal is routed on the different optical wavelength input ports of said sub-carrier modulation unit; Described sub-carrier modulation unit is used for modulation behind the CF signal shift frequency and is multiplexed into one tunnel optical wavelength, and sends through different optical wavelength output ports.
7. the wireless access system based on the centralization base station according to claim 1 is characterized in that, said optical cross-connection unit is routed to different wavelength division multiplexing unit according to service needed with different optical wavelength, realizes the dynamic assignment of optical wavelength.
8. carrier moving method based on the centralization base station comprises:
(1) dynamic-configuration is carried out with CF signal or virtual carrier frequency is moved in the centralization base station, then with the modulation of the CF signal behind the shift frequency be multiplexed on the light wave, and is routed to different far-end antenna elements;
(2) said far-end antenna element extracts and is modulated to the said CF signal on the light wave, arrives institute's region covered via transmission antennas transmit;
In the step (1), the step that said virtual carrier frequency is moved comprises:
(11) the mapping relation table is carried out initialization and renewal;
(12) mapping relations of change CF signal and subcarrier shift frequency frequency make said CF signal produce shift frequency and form modulating frequency, and said modulating frequency is modulated and is multiplexed on one tunnel optical wavelength; In shift frequency, modulation and multiplex process, observe said mapping relations table;
(13) with said optical wavelength multiplexing to optical fiber link, in multiplex process, observe said mapping relations table.
9. the carrier moving method based on the centralization base station according to claim 8; It is characterized in that; In the step (1), when virtual carrier frequency is moved, adopt and close on principle, said close on pay the utmost attention in the principle move sub-carrier modulation after the close CF signal of frequency; Consider to move the CF signal that closes on the optical wavelength then, consider to move the CF signal that closes on the optical fiber link at last.
10. the carrier moving method based on the centralization base station according to claim 8; It is characterized in that; In the step (11), said mapping relations table comprises CF signal tabulation, shift frequency list of frequency, modulating frequency tabulation, optical wavelength tabulation, the tabulation of interconnection optical wavelength, wavelength division multiplexing tabulation and optical fiber link tabulation.
11. the carrier moving method based on the centralization base station according to claim 8; It is characterized in that; In the step (11); When disposing said mapping relations table, avoid carrying on the optical wavelength two or more, perhaps avoid on an optical fiber, carrying two or more identical optical wavelength with wireless carrier signal frequently.
12. the carrier moving method based on the centralization base station according to claim 10 is characterized in that, in the step (12), the radio frequency cross linkage unit is routed to the sub-carrier modulation unit through calling said CF signal tabulation with said CF signal; The said shift frequency list of frequency of sub-carrier modulation cell call, modulating frequency tabulation and optical wavelength tabulation with the shift frequency frequency effect in said CF signal and the sub-carrier modulation unit, produce modulating frequency, then this modulating frequency are modulated and are multiplexed on the optical wavelength; In the step (13), optical cross-connection unit calls the tabulation of interconnection optical wavelength, and the optical wavelength of carrying CF signal is carried out the interconnection of optical wavelength, and sends; Wavelength division multiplexing cell call wavelength division multiplexing tabulation, with said optical wavelength multiplexing to optical fiber link.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
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| CN2007101229821A CN101340647B (en) | 2007-07-04 | 2007-07-04 | Wireless access system and carrier moving method based on centralized base station |
| PCT/CN2007/003952 WO2009003338A1 (en) | 2007-07-04 | 2007-12-29 | Wireless access system based on centralized base station and carrier shift method |
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| CN2007101229821A CN101340647B (en) | 2007-07-04 | 2007-07-04 | Wireless access system and carrier moving method based on centralized base station |
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| CN101340647B true CN101340647B (en) | 2012-02-29 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106358202A (en) * | 2016-10-13 | 2017-01-25 | 北京邮电大学 | Improved C-RAN network architecture and resource dispatching method |
Families Citing this family (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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| EP2842245A1 (en) | 2012-04-25 | 2015-03-04 | Corning Optical Communications LLC | Distributed antenna system architectures |
| US9455784B2 (en) | 2012-10-31 | 2016-09-27 | Corning Optical Communications Wireless Ltd | Deployable wireless infrastructures and methods of deploying wireless infrastructures |
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| US9681313B2 (en) | 2015-04-15 | 2017-06-13 | Corning Optical Communications Wireless Ltd | Optimizing remote antenna unit performance using an alternative data channel |
| US9948349B2 (en) | 2015-07-17 | 2018-04-17 | Corning Optical Communications Wireless Ltd | IOT automation and data collection system |
| CN106304419B (en) * | 2016-08-15 | 2020-06-12 | 上海交通大学 | Wireless forward transmission system for digital optical transmission based on multi-core optical fiber |
| CN110557613A (en) * | 2019-09-04 | 2019-12-10 | 深圳供电规划设计院有限公司 | Distributed video monitoring system and method |
| CN111246551B (en) * | 2020-01-13 | 2022-04-22 | 武汉信科移动通信技术有限公司 | Method and system for acquiring occupied frequency point of virtual multi-carrier communication system terminal |
| CN114039665B (en) * | 2021-11-12 | 2023-10-31 | 大连海事大学 | Multi-carrier frequency generation and reliable transmission method for RoF system |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1280450A (en) * | 1999-07-09 | 2001-01-17 | 现代电子产业株式会社 | Transmit-receiver base station of digit mobile communication system |
| US6222653B1 (en) * | 1997-04-02 | 2001-04-24 | Nec Corporation | Optical communication node and wavelength division multiplexing optical transmission device having ring structure comprising the optical communication nodes |
| CN1661941A (en) * | 2004-02-23 | 2005-08-31 | 华为技术有限公司 | Distributed base stations and data interactive method |
| CN1941955A (en) * | 2005-09-29 | 2007-04-04 | 日立通讯技术株式会社 | Wireless base station and communication method therefor |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100487215B1 (en) * | 2003-01-03 | 2005-05-04 | 삼성전자주식회사 | Wdm self-curable ring-type optical communication network |
-
2007
- 2007-07-04 CN CN2007101229821A patent/CN101340647B/en active Active
- 2007-12-29 WO PCT/CN2007/003952 patent/WO2009003338A1/en active Application Filing
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6222653B1 (en) * | 1997-04-02 | 2001-04-24 | Nec Corporation | Optical communication node and wavelength division multiplexing optical transmission device having ring structure comprising the optical communication nodes |
| CN1280450A (en) * | 1999-07-09 | 2001-01-17 | 现代电子产业株式会社 | Transmit-receiver base station of digit mobile communication system |
| CN1661941A (en) * | 2004-02-23 | 2005-08-31 | 华为技术有限公司 | Distributed base stations and data interactive method |
| CN1941955A (en) * | 2005-09-29 | 2007-04-04 | 日立通讯技术株式会社 | Wireless base station and communication method therefor |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106358202A (en) * | 2016-10-13 | 2017-01-25 | 北京邮电大学 | Improved C-RAN network architecture and resource dispatching method |
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| CN101340647A (en) | 2009-01-07 |
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