The wireless multi-carrier communications method of tdd mode mimo wireless communication system and device
Technical field
The invention belongs to wireless communication technology field, be particularly related to a kind of time division duplex (Time Division Duplexing, TDD) wireless multi-carrier communications method and the device of pattern multiple-input and multiple-output (Multiple Input Multiple Output, MIMO) wireless communication system.
Background technology
3G (Third Generation) Moblie is as WCDMA technology, and it is non-MIMO technology, the mode of operation of Frequency Division Duplexing (FDD) (Frequency Division Duplexing, FDD), and its single carrier channel bandwidth 5MHz, realizes 3.84Mbps symbol transmission speed.For improving power system capacity, there is the mode that adopts multi-carrier transmission base station, but this technology is to realize under fdd mode, working frequency range 2110~the 2170MHz of its downlink signal, the working frequency range of uplink receiving signal: 1920~1980MHz, its downlink signal and uplink receiving signal frequency interval are very large, directly adopt in radio frequency part and close road or digital if technology can realize multi-transceiver technology.
Long Term Evolution (Long Term Evolution, LTE) and WLAN (wireless local area network) (Wireless Local Area Networks, WLAN) physical layer adopts OFDM (Orthogonal Frequency Division Multiplexing, OFDM) technology, it refers to Base-Band Processing part individual channel is divided into one group of mutually orthogonal subcarrier, in radio frequency part, is to use single carrier wave to send the signal of a channel.Multicarrier of the present invention refers to the radio frequency part of tdd mode mimo wireless communication system and uses a plurality of carrier waves to send the signal of a plurality of channels, and each carrier wave sends the signal of a channel.
The ultrahigh speed wireless local area network technology IEEE802.11ac of low-frequency range 5.8GHz is 80MHz in the maximum channel width of product in the market, outdoor double space flow transmission speed can reach 866.7Mbps, but the passback of the 4th third-generation mobile communication technology LTE base station in the market and multi-channel video flow transmission need transmission rate more than 1Gbps.China is 5.725~5.85GHz in 5.8GHz frequency range, only has the bandwidth of 125MHz, is less than the 80MHz bandwidth of 2 times, has no idea to realize multi-carrier transmission in this frequency range.
Low-frequency range (lower than 6GHz) wireless communication spectrum resource is day by day rare, the demand of Ultrahigh speed data transmission rate and the frequency resource of millimeter wave frequency band are very abundant, millimeter wave frequency band ultrahigh speed wireless communication technology is more and more received publicity, in December, 2013 for example, the frequency spectrum resource that Ministry of Industry and Information's approval amounts to 42.3~47GHz and 47.2~48.4GHz to 5.9GHz is for ultrahigh speed wireless access and without radio license.
Utilize the single carrier baseband chip of IEEE802.11ac to realize multi-carrier transmission under tdd mode, each intercarrier is nonsynchronous, can cause transmitting of a carrier wave to be directly leaked to the receiver of another one carrier wave, make its receiver saturated, can not work.The present invention will use frequency conversion to produce the carrier wave of different frequency, utilize the multi-transceiver technology of the separated intercarrier signal isolation producing of filter and different carrier antenna to overcome this problem, realize the transmission of tdd mode multi-carrier, the data transmission throughput of wireless communication system is multiplied, when Base Band Unit adopts IEEE802.11ac technical specification, the transmission rate of the wireless communication system of 2 carrier wave double space streams is up to 1.733Gbps.
Tdd mode generally adopts transceiver toggle switch to realize the separated of transmitter signal and receiver signal, due to millimeter wave frequency band transceiver toggle switch, to realize difficulty larger, loss is also larger, and the present invention uses the transmitting antenna method separated with reception antenna to realize the mode of operation of TDD.
Summary of the invention
Goal of the invention: low-frequency range (lower than 6GHz) wireless communication spectrum resource is day by day rare, be widely used interference very large, have a strong impact on systematic function, even can not effectively work, the present invention adopts frequency conversion to produce the carrier wave of different frequency, utilize filter, the multi-transceiver technology of the separation of different carrier antenna and dual-mode antenna separation, the transmitting of the asynchronous carrier wave causing overcoming between Transmit enable problem under tdd mode and multicarrier is leaked to the receiver of another one carrier wave, make its receiver saturated, the problem that can not work, effectively utilize the very abundant frequency resource of millimeter wave frequency band, the data transmission throughput of wireless communication system is multiplied, the passback of satisfied the 4th third-generation mobile communication technology LTE base station in the market and multi-channel video flow transmission are up to the requirement of transmission rate more than 1Gbps.
Technical scheme: for foregoing invention object, the present invention adopts following technical scheme:
A kind of wireless multi-carrier communications method of tdd mode mimo wireless communication system, described wireless communication system has N roadbed band signal, every roadbed band signal comprises two spatial flow signals, wherein, N is greater than 1 natural number, the method is by the separated mode of operation that realizes TDD of transmitting antenna and reception antenna, and the step of method is:
The frequency range that transmitter up-converts to two spatial flows by the baseband signal of each two spatial flow in road is F
1single carrier radiofrequency signal after up-convert to again two spatial flows frequency range be F
2single carrier microwave frequency band signal after synthesize again single channel orthogonal polarization double space stream single carrier microwave frequency band signal by a transmitting antenna, send, the single carrier microwave frequency band signal of the double space stream different frequency of the N road orthogonal polarization that the baseband signal of two spatial flows in N road produces sends by N transmitting antenna;
The single carrier microwave frequency band signal of the double space stream different frequency of N road orthogonal polarization is isolated in the isolation that receiver uses different antennas to bring by N filter and different carrier the signal of the double space stream microwave frequency band of the orthogonal polarization of the N receiving from a N reception antenna carrier wave, then the double space of each road orthogonal polarization is flowed to single carrier microwave frequency band signal is separated into the baseband signal that down-converts to again two spatial flows after the single carrier radiofrequency signal that down-converts to again two spatial flows after the single carrier microwave frequency band signal of two spatial flows.
Wherein, the concrete steps that transmitter signal is processed are:
1.1) each roadbed band signal spatial flow signal produces single carrier radiofrequency signal through I/Q modulator upconversion process, upconverts to more high band again and produce single carrier microwave frequency band signal after the filtering of single carrier radiofrequency signal; Another spatial flow signal of baseband signal is adopted to use the same method and is produced the single carrier microwave frequency band signal of another spatial flow;
1.2) the single carrier microwave frequency band signal of two spatial flows sends by a transmitting antenna synthesize the double space stream single carrier microwave frequency band signal of single channel orthogonal polarization by orthomode coupler (Orthogonal Mode Transducer, OMT) after.
The concrete steps that receiver signal is processed are:
2.1) receiver is separated into the single carrier microwave frequency band signal of two spatial flows by the double space stream single carrier microwave frequency band signal of each road orthogonal polarization by orthomode coupler;
2.2) by step 2.1) in the single carrier microwave frequency band signal of each spatial flow of single carrier microwave frequency band signal of two spatial flows down-convert to single carrier radiofrequency signal, after the filtering of single carrier radiofrequency signal, through i/q demodulator demodulation, produce baseband signal again.
Employing is a multi-carrier communication apparatus for the tdd mode mimo wireless communication system of method as above, comprises N transmitter processes path and N receiver processing path; Each transmitter processes path comprises a transmitter baseband processing unit, a radio frequency sending set processing unit, a microwave frequency band upconversion process unit, a transmitter orthomode coupler, a transmitter filter and a transmitting antenna; Each receiver is processed path and is comprised a receiver baseband processing unit, a radio-frequency transmitter processing unit, a microwave frequency band frequency conversion processing unit, a receiver orthomode coupler, a filter for receiver and a reception antenna;
Described transmitter baseband processing unit, receiver baseband processing unit, radio frequency sending set processing unit, radio-frequency transmitter processing unit, microwave frequency band upconversion process unit, microwave frequency band frequency conversion processing unit comprise respectively two signals processing subpaths, and each signal is processed subpath for the processing of a road spatial flow signal;
Described transmitter baseband processing unit produces the baseband signal of one group of two spatial flow, and exports radio frequency sending set processing unit to;
The input of described radio frequency sending set processing unit is connected with the output of transmitter baseband processing unit, for the baseband signal of two spatial flows being converted to the frequency range of two spatial flows, is F
1single carrier radiofrequency signal, and export microwave frequency band upconversion process unit to;
The input of described microwave frequency band upconversion process unit is connected with radio frequency sending set processing unit output, for the single carrier radiofrequency signal of two spatial flows being converted to the frequency range of two spatial flows, is F
2single carrier microwave frequency band signal; The single carrier microwave frequency band signal of the different frequency of two spatial flows in output N road, the N in N transmitter processes path microwave frequency band upconversion process unit;
Two inputs of described transmitter orthomode coupler are connected with the output of two the signal processing subpaths in microwave frequency band upconversion process unit respectively, the common port of transmitter orthomode coupler is connected with transmitter filter, and transmitter filter is connected with transmitting antenna; Transmitter orthomode coupler is for the single carrier microwave frequency band signal of two spatial flows being synthesized to the double space stream single carrier microwave frequency band signal of single channel orthogonal polarization, and the double space stream single carrier microwave frequency band signal of exporting single channel orthogonal polarization sends by transmitting antenna to transmitter filter;
The input of described filter for receiver is connected with reception antenna, for by antenna reception to the signal of double space stream multicarrier microwave frequency band of orthogonal polarization carry out filtering, and the double space stream single carrier microwave frequency band signal of output orthogonal polarization is to receiver orthomode coupler;
The common port of described receiver orthomode coupler is connected with the output of filter for receiver, the input that two outputs are processed subpaths with two signals of microwave frequency band frequency conversion processing unit is respectively connected, and receiver orthomode coupler is for being separated into the single carrier microwave frequency band signal of two spatial flows by the double space stream single carrier microwave frequency band signal of orthogonal polarization and exporting respectively two signals processing subpaths of microwave frequency band frequency conversion processing unit to;
Described microwave frequency band frequency conversion processing unit is used for converting the single carrier microwave frequency band signal of two spatial flows the single carrier radiofrequency signal of two spatial flows to, and exports radio-frequency transmitter processing unit to;
The input of described radio-frequency transmitter processing unit is connected with the output of microwave frequency band frequency conversion processing unit, for the single carrier radiofrequency signal of two spatial flows being converted to the baseband signal of two spatial flows, and exports receiver baseband processing unit to.
More common in transmitter baseband processing unit, receiver baseband processing unit, radio frequency sending set processing unit, radio-frequency transmitter processing unit prior art.The baseband signal of two spatial flows of transmitter baseband processing unit output is two inputs of processing subpath of input radio frequency transmitter processes unit respectively, the single carrier radiofrequency signal of two spatial flows of the output output of two processing subpaths of radio frequency sending set processing unit is the input of two signals processing subpaths of incoming wave frequency range upconversion process unit respectively, and the output of two signals processing subpaths of ripple frequency range upconversion process unit is exported the single carrier microwave frequency band signal of two spatial flows.Process two single carrier radiofrequency signals of processing two spatial flows of subpath output that subpath receives respectively microwave frequency band frequency conversion processing unit for two of radio-frequency transmitter processing unit, two baseband signals of processing two spatial flows of subpath output of radio-frequency transmitter processing unit are to receiver baseband processing unit.
Wherein, microwave frequency band upconversion process unit signal processing subpath comprises:
Radio-frequency signal filters, processes for a signal of received RF transmitter processes unit the radiofrequency signal that subpath is exported, and carries out exporting after filtering; Radiofrequency signal upconverter, for the radiofrequency signal of received RF signal filter output, exports after use microwave frequency band local oscillation signal up-converts to microwave frequency band signal by radiofrequency signal; Microwave frequency band traffic filter, the microwave frequency band signal for the output of received RF signal upconverter, carries out exporting after filtering; And microwave frequency band signal power amplifier, for receiving the microwave frequency band signal of microwave frequency band traffic filter output, carry out exporting after power amplification;
A signal of microwave frequency band frequency conversion processing unit is processed subpath and is comprised:
Microwave frequency band signal low noise amplifier, for receiving the microwave frequency band signal of transceiver toggle switch output, carries out exporting after low noise amplification; Microwave frequency band traffic filter, for receiving the microwave frequency band signal after the amplification of microwave frequency band signal low noise amplifier output, carries out exporting after filtering; Microwave frequency band signal low-converter, for receiving the microwave frequency band signal of microwave frequency band traffic filter output, exports after use microwave frequency band local oscillation signal down-converts to radiofrequency signal by microwave frequency band signal; And radiofrequency signal channel model, for receiving the radiofrequency signal of microwave frequency band signal low-converter output, carry out exporting after filtering.
The separation and Extraction of multi-carrier signal has been come together by the separation of different carrier antenna, transmitter filter, filter for receiver, radiofrequency signal channel model.The transmitter filter of same carrier frequencies is the same with filter for receiver design, transmitter filter is filtering spurious signal, the spurious signal that comprises other carrier wave frequency range, prevent from disturbing receiver and other wireless device of other carrier wave, after the separation of different carrier antenna, consider equipment size, distance between them can be closer, filter for receiver needs the transmitter signal of other carrier wave of filtering to disturb and the outer interference signal of other wireless device band, prevents that the saturated receiver sensitivity of receiver from reducing.The designing requirement of concrete filter and the isolation between different carrier antenna, between same carrier wave dual-mode antenna, insulation request is as follows:
The inhibition degree D of filter for receiver to adjacent carrier
1, isolation D between the transmitting antenna of different carrier and reception antenna
2and be isolated into D between same carrier wave dual-mode antenna
3the following formula of design consideration determine:
P
1-D
2-D
1≤-174-9 formula 1
D
1+ D
2>=183+P
1formula 2
P
tx-D
2-D
1≤ P
2formula 3
P
tx-D
3≤ P
3formula 4
D
1+ D
2>=P
tx-P
2formula 5
P
tx-(A
1+ A
2+ D
2+ D
1the 174+10log of)≤-(B)+60 formula 6
Wherein, the noise floor of receiver :-174dBm/Hz, for making reduction value that the spurious signal of transmitter affects receiver sensitivity not higher than 0.5dB, the spurious signal of transmitter must be lower than the noise floor 9dB of receiver at receiver end, after the radio-frequency signal filters of microwave frequency band upconversion process unit, the filtering of microwave frequency band traffic filter, the single carrier microwave frequency band signal of transmitter microwave frequency band upconversion process unit output is at the spurious signal level at adjacent another one carrier wave frequency range place: P
1dBm/Hz, the single carrier maximum input signal level of receiver microwave frequency band frequency conversion processing unit: P
2dBm, the maximum input of single carrier of receiver microwave frequency band frequency conversion processing unit does not damage signal level: P
3dBm, transmitter single carrier microwave frequency band signal output level: P
txdBm, the radiofrequency signal channel model in microwave frequency band frequency conversion processing unit at the inhibition degree of adjacent carrier is: A
1dB, the microwave frequency band traffic filter in microwave frequency band frequency conversion processing unit at the inhibition degree of adjacent carrier is: A
2dB, single carrier microwave frequency band signal bandwidth: BMHz.
The bandwidth of transmitter filter can be greater than single carrier channel bandwidth, and its bandwidth selection is according to millimeter wave frequency band F
2decide with the insertion loss of filter, be chosen as the width of 2% left and right of carrier wave.
Radiofrequency signal channel model, is used for completing together the separated of multi-carrier signal with filter for receiver, and the frequency range of radiofrequency signal channel model is F
1, this frequency range is compared with low-frequency range, is chosen as and is less than 6GHz, and the transceiver of each carrier wave is the same in the frequency of this frequency range, and the bandwidth of radiofrequency signal channel model is the channel width of single carrier radiofrequency signal.
Orthomode coupler, also claim orthomode transducer or bimodulus converter, be used for the device of polarized wave of isolated or synthesized two quadratures, solve under sighting distance (LOS) environment and can transmit with polarised direction channels different and isolation mutually the problem of 2 spatial flows on same frequency.Transmitter orthomode coupler is the same with the design of receiver orthomode coupler, and orthomode coupler has three physical ports, and public port is connected with antenna, and two other electrical port is distributed to respectively the transceiver of 2 spatial flows.
Wireless communication system comprises WAP (wireless access point), client.Wherein WAP (wireless access point) also can be described as central station, and client also can be described as remote terminal.WAP (wireless access point) can realize by the method for above-mentioned transmitter and receiver, and client also can realize by the method for above-mentioned transmitter and receiver.
Beneficial effect: compared with prior art, the present invention effectively utilizes the very abundant frequency resource of millimeter wave frequency band, the data transmission throughput of wireless communication system is multiplied, when Base Band Unit adopts IEEE802.11ac technical specification, the peak rate of the wireless communication system of 2 carrier wave double space streams can be brought up to 1.733Gbps.
Accompanying drawing explanation
Fig. 1 is the schematic diagram of mimo wireless communication network;
Fig. 2 is the structural representation of apparatus of the present invention embodiment;
Fig. 3 is principle schematic of the present invention;
Fig. 4 is the circuit block diagram of the baseband processor+5.8GHz radio-frequency (RF) transceiver in Fig. 3;
Fig. 5 be apparatus of the present invention embodiment in the structural representation of OMT.
Embodiment
Technology of the present invention can be for multiple system of broadband wireless communication, and the example of this communication system comprises tdd mode millimeter wave wireless MIMO communication system etc.
Method of the present invention can realize in multiple wired or wireless communication device, and the radio node that the method according to the present invention realizes can comprise access point or user terminal.
Access point (Access Point, AP) can comprise, be implemented as or be called base station transceiver, central station, base station, transceiver function, wireless router, transceiver, Basic Service Set (Basic Service Set, BSS), extended service set (Extended Service Set, ESS) or some other term.
User terminal (User Terminal, UT) can comprise, be implemented as or be called access terminal, remote terminal, subscriber station, subscriber unit, mobile radio station, user terminal, user's set, subscriber equipment or some other term.In some implementation, access terminal and can comprise phone, mobile phone, computer of possessing wireless connections ability etc.
The multiple access mimo system as shown in Figure 1, with access point and user terminal.In any given moment, access point can communicate with one or more user terminals in down link and up link.Down link is the communication link from access point to user terminal, and up link is the communication link from user terminal to access point.User terminal can also be communicated by letter point-to-pointly with another user terminal.System access controller is connected to access point, and provides and coordinate and control to access point.
Wireless MIMO communication system is tdd mode system, and for TDD system, down link and up link are shared identical frequency band.
Access point is for the transmitter of down link with for the receiver of up link.User terminal is for the receiver of down link with for the transmitter of up link." transmitter " is to send by wireless channel device or the equipment of the independent operation of data as used in this article, and " receiver " is to receive by wireless channel device or the equipment of the independent operation of data.
As shown in Figure 3 and Figure 4, the invention discloses a kind of wireless multi-carrier communications method and principle of device schematic diagram of tdd mode mimo wireless communication system.The inventive method comprises the following steps:
(1) transmitter baseband processing unit can generate baseband signal according to IEEE802.11ac technical specification, and the process I/Q modulator of baseband signal upconverts to F
1frequency range produces radiofrequency signal, F
1the following low-frequency range of optional 6GHz, is preferably 5.8GHz, and signal bandwidth is 80MHz, and this radiofrequency signal upconverts to higher F after filter filtering again
2frequency range produces microwave frequency band signal, F
2optional 10GHz, with super band, is preferably 45GHz frequency range, produces according to the method described above the microwave frequency band signal of N road single carrier, and its carrier frequency is respectively f
1..., f
n.During 2 carrier schemes, produce the microwave frequency band signal of 2 road single carriers, f
1be chosen as: 42.565GHz, f
2be chosen as: 47.3GHz; The baseband signal of two spatial flows in N road of N transmitter baseband processing unit generation is used respectively said method to produce the signal of the single carrier microwave frequency band of two spatial flows in N road.
The signal of the microwave frequency band of N carrier wave of (2) two spatial flows is inputted respectively the different input of OMT separately, after OMT is synthetic, connects the signal that N transmitting antenna just can send the multicarrier microwave frequency band of 2 road spatial flows.The double space stream signal of every road carrier wave is used an antenna to send, and N road single carrier needs N antenna to send, and during 2 carrier schemes, 2 carrier waves need 2 transmit antennas.
(3) receiver receives the signal of the microwave frequency band of multicarrier from N root reception antenna, while implementing 2 carrier schemes, receives the microwave frequency band signal of 2 carrier waves, wherein f from 2 antennas
1be chosen as: 42.565GHz, f
2be chosen as: 47.3GHz, this signal is inputted each road filter for receiver, and filter for receiver is isolated single carrier microwave frequency band signal separately, then inputs OMT, and OMT isolates the microwave frequency band F of single carrier of 2 road spatial flows of orthogonal polarization
2signal, F
2it can be 45GHz frequency range.
(4) after Jiang Mei road single carrier microwave frequency band signal microwave down-conversion, produce F
1the radiofrequency signal of frequency range, F
1be chosen as 5.8GHz, this signal carries out filtering through radiofrequency signal channel model, produce clean single carrier radiofrequency signal, the bandwidth of channel model is chosen as 80MHz, then this signal input i/q demodulator is carried out to demodulation and produce baseband signal, baseband signal input receiver baseband processing unit is processed.
As shown in Figure 2, a kind of multi-carrier communication apparatus of tdd mode mimo wireless communication system, comprises N transmitter processes path and N receiver processing path; Each transmitter processes path comprises transmitter baseband processing unit 1, radio frequency sending set processing unit 2, microwave frequency band upconversion process unit 3, transmitter orthomode coupler 4, transmitter filter 5 and transmitting antenna 6; Each receiver is processed path and is comprised receiver baseband processing unit 10, radio-frequency transmitter processing unit 20, microwave frequency band frequency conversion processing unit 30, receiver orthomode coupler 40, filter for receiver 50 and reception antenna 60.
Transmitter baseband processing unit 1, receiver baseband processing unit 10, radio frequency sending set processing unit 2, radio-frequency transmitter processing unit 20, microwave frequency band upconversion process unit 3, microwave frequency band frequency conversion processing unit 30 comprise respectively two signals processing subpaths, and each signal is processed subpath for the processing of a road spatial flow signal.
The baseband signal of two spatial flows that transmitter baseband processing unit 1 produces exports respectively two signals of radio frequency sending set processing unit 2 to and processes subpath, two signals of radio frequency sending set processing unit 2 are processed two signals processing subpaths that subpath is converted to the baseband signal of two spatial flows respectively the single carrier radiofrequency signal of two spatial flows and exports respectively microwave frequency band upconversion process unit 3 to, the frequency of the N road single carrier radiofrequency signal of N radio frequency sending set processing unit 2 outputs is identical, frequency range F
1for being less than 6GHz frequency range; Microwave frequency band upconversion process unit 3 is converted to the single carrier radiofrequency signal of two spatial flows the single carrier microwave frequency band signal of two spatial flows, the single carrier microwave frequency band signal of the N road different frequency of N microwave frequency band upconversion process unit 3 outputs, frequency range F
2for being greater than 10GHz microwave frequency band, the frequency of N road single carrier microwave frequency band signal is respectively f
1..., f
n; The single carrier microwave frequency band signal of two spatial flows of the signal processing subpath output of microwave frequency band upconversion process unit 3 sends by transmitting antenna 6 to transmitter filter 5 filtering by the double space stream single carrier microwave frequency band signal of the synthetic output orthogonal polarization of transmitter orthomode coupler 4.
The signal of double space stream microwave frequency band that receiver receives reception antenna 60 orthogonal polarization of multicarrier exports filter for receiver 50 to, and filter for receiver 50 carries out the double space stream single carrier microwave frequency band signal of output orthogonal polarization after filtering to receiver orthomode coupler 40, the single carrier microwave frequency band signal that receiver orthomode coupler 40 is separated into two spatial flows by the double space stream single carrier microwave frequency band signal of orthogonal polarization exports respectively two signals of microwave frequency band frequency conversion processing unit 30 to and processes subpaths, microwave frequency band frequency conversion processing unit 30 is converted to the single carrier microwave frequency band signal of two spatial flows the single carrier radiofrequency signal of two spatial flows and exports radio-frequency transmitter processing unit 20 to, radio-frequency transmitter processing unit 20 converts the single carrier radiofrequency signal of two spatial flows to the baseband signal of two spatial flows, and export receiver baseband processing unit 10 to.
Fig. 3 and Fig. 4 have provided the concrete structural representation of the present embodiment, below one of Yi Yi road signal process subpath and specifically describe Radio frequency Processing Unit, RF Processing Unit and the annexation of microwave frequency band frequency-conversion processing part and the transitive relation of signal:
One of radio frequency sending set processing unit 2 process subpath: baseband signal is converted to i/q signal by digital analog converter 21 and exports, i/q signal through two analog intermediate frequency filters 22, two analog intermediate frequency amplifiers 23, carry out filtering respectively and amplify after input to I/Q modulator 24 be modulated to input again variable gain amplifier 25 after radiofrequency signal and amplify after output single carrier radiofrequency signal.
Process subpath for one of microwave frequency band upconversion process unit 3: variable gain amplifier 25 output single carrier radiofrequency signals are by input radio frequency signal upconverter 32 after radio-frequency signal filters 31 filtering, carry out up-converting to after mixing the output of microwave frequency band signal with microwave frequency band local oscillation signal, then after microwave frequency band traffic filter 33, power amplifier 34 carry out filtering and power amplification output single carrier microwave frequency band signal.
Process subpath for one of microwave frequency band frequency conversion processing unit 30: single carrier microwave frequency band signal is inputted microwave frequency band signal low-converter 303 input 302 filtering of microwave frequency band traffic filter after low noise amplifier 301 carries out low noise amplification after again, carry out down-converting to after mixing radiofrequency signal output with microwave frequency band local oscillation signal, then after radiofrequency signal channel model 304 carries out filtering output single carrier radiofrequency signal.
Process subpath for one of radio-frequency transmitter processing unit 20: the single carrier radiofrequency signal of above-mentioned channel model 304 outputs is inputted i/q demodulator 202 after amplifying by amplifier 201 and carried out demodulation, output i/q signal, i/q signal respectively through two variable gain amplifiers 203, two analog intermediate frequency filters 204 amplify and filtering after input after analog-digital converter 205 is converted to baseband signal and export.
The separation and Extraction of multi-carrier signal has been come together by the separation of different carrier antenna, transmitter filter 5, filter for receiver 50, channel model 304.The transmitter filter 5 of same carrier frequencies is the same with filter for receiver 50 designs, transmitter filter 5 is filtering spurious signals, the spurious signal that comprises other carrier wave frequency range, prevent from disturbing receiver and other wireless device of other carrier wave, after the separation of different carrier antenna, consider equipment size, distance between them can be closer, filter for receiver 50 needs the transmitter signal of other carrier wave of filtering to disturb and the outer interference signal of other wireless device band, prevents that the saturated receiver sensitivity of receiver from reducing.
Below describing the parameter of isolation between the isolation between transmitter filter 5, filter for receiver 50, different carrier antenna, same carrier wave dual-mode antenna, channel model 304, transmitter orthomode coupler 4 and receiver orthomode coupler 40 while implementing 2 carrier schemes selects, wherein, the transmitter filter 5 of same carrier wave is the same with the design of filter for receiver 50, and transmitter orthomode coupler 4 is the same with the design of receiver orthomode coupler 40.F
1elect as: 42.565GHz, f
2elect as: 47.3GHz; F
1elect 5.8GHz as; Single carrier microwave frequency band signal bandwidth: 80MHz, baseband processor is selected the baseband processing chip of IEEE802.11ac technical specification.
The inhibition degree D of transmitter filter 5 or 50 pairs of adjacent carriers of filter for receiver
1, different carrier isolation between antennas D
2and be isolated into D between same carrier wave dual-mode antenna
3the above-mentioned formula 1 of design consideration to formula 6 determine.Wherein, the noise floor of receiver :-174dBm/Hz, after radio-frequency signal filters 31,33 filtering of microwave frequency band traffic filter, the single-carrier signal of transmitter microwave frequency band upconversion process unit output is at the spurious signal level at adjacent another one carrier wave frequency range place: P
1=-134dBm/Hz, the single carrier maximum input signal of receiver microwave frequency band frequency conversion processing unit: P
2=-20dBm, the maximum input of single carrier of receiver microwave frequency band frequency conversion processing unit does not damage signal level: P
3=2dBm, transmitter antenna mouth single-carrier signal output level: P
tx=20dBm, the channel model 304 in microwave frequency band frequency conversion processing unit at the inhibition degree of adjacent carrier is: A
1=50dB, the microwave frequency band traffic filter 302 in microwave frequency band frequency conversion processing unit at the inhibition degree of adjacent carrier is: A
2=30dB, single carrier microwave frequency band signal bandwidth: B=80MHz.
According to formula 4 and formula 6, D
1+ D
2>=49, can select D
1>=29dB, antenna isolation D between different carrier
2>=20dB; Antenna isolation D between same carrier wave
3>=18dB.
The bandwidth of transmitter filter 5 can be greater than single carrier channel bandwidth, and its bandwidth selection is according to millimeter wave frequency band F
2decide with the insertion loss of filter, be chosen as the width of 2% left and right of carrier wave.Single carrier separation is to use filter for receiver 50 and channel model 304 to come together, and in 2 carrier schemes, the bandwidth of each transmitter filter 5 is elected 1080MHz as, and centre frequency is respectively 42.565GHz and 47.3GHz.
Channel model 304, be used for completing together the separated of multi-carrier signal with filter for receiver 50, the frequency range of channel model is elected 5.8GHz as, the transceiver of each carrier wave is the same in the frequency of this frequency range, the bandwidth of channel model 304 is the channel width of single carrier radiofrequency signal, and its inhibition degree at adjacent carrier place is: A
1dB, the present embodiment design A
1=50dB.
Orthomode coupler, also claim orthomode transducer or bimodulus converter, be used for the device of polarized wave of isolated or synthesized two quadratures, solve under sighting distance (LOS) environment and can transmit with polarised direction channels different and isolation mutually the problem of 2 spatial flows on same frequency.Transmitter orthomode coupler 4 is the same with the design of receiver orthomode coupler 40, and orthomode coupler has three physical ports, and public port is connected with antenna, and two other electrical port is distributed to respectively the transceiver of 2 spatial flows.Orthomode coupler can be selected circle common waveguide diaphragm branch design, as shown in Figure 5, uses the evenly common circle waveguide of cut-off, and cross section is divided in the insertion of diaphragm equally.Diaphragm region (or local) after rectangle branch-waveguide is overlapping with branch-waveguide, and Waveguide branching is positioned at common waveguide with respect to the central authorities of the vertical sidewall of diaphragm, the longitudinal axis conllinear of the general and common waveguide of the wide wall of branch-waveguide.Be added to the TE of public port
10mould signal is divided into two equal portions by membrane areas in the porch of diaphragm, then reconfigures in waveguide subsequently.The TE of quadrature
01mould disappears and reflects in diaphragm region, is finally coupled in branch-waveguide.The reflection loss of two kinds of polarized waves is greater than 20dB, and isolation is greater than 40dB.
The BCM4352 of the QCA9892 of the optional Qualcomm of baseband signal processor+5.8GHz radio-frequency (RF) transceiver (Qualcomm) or Botong company (Broadcom) in Fig. 3, the QCA9558 of the optional QualCom of network processing unit company (Qualcomm).
The above is only the preferred embodiment of the present invention, for those skilled in the art, under the premise without departing from the principles of the invention, any modification of doing, is equal to replacement, improvement etc. and also should be considered as protection scope of the present invention.