CN103095351B - Multi-input and multi-output system based on single carrier and full duplex - Google Patents
Multi-input and multi-output system based on single carrier and full duplex Download PDFInfo
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- CN103095351B CN103095351B CN201310016132.9A CN201310016132A CN103095351B CN 103095351 B CN103095351 B CN 103095351B CN 201310016132 A CN201310016132 A CN 201310016132A CN 103095351 B CN103095351 B CN 103095351B
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Abstract
The invention provides a multi-input and multi-output system based on single carrier and full duplex. The system mainly solves the problems of hidden terminals, network congestion and system undercapacity in wireless networks. The system comprises a Multiple Input Multiple Output (MIMO) sending signal processing module (1), a transceiver (3), an MIMO receiving signal processing module (5), an echo canceling network (6), a strong self-interference elimination module (7) and a digital domain interference elimination module (8). After the MIMO sending signal processing module (1) outputs signals of multiple branches, signals of each branch are transmitted through the transceiver (3) after digital-to-analogue conversion and up-conversion and after being processed in the echo canceling network. Receiving signals of the transceiver (3) are transmitted to the MIMO receiving signal processing module (5) to be processed through down-conversion and analog-digital conversion after signal interference elimination through the echo canceling network (6), the strong self-interference elimination module (7) and the digital domain interference elimination module (8). The system is capable of reducing effect on useful signals by self-interference to the maximum extent and can be used for wireless packet communication.
Description
Technical field
The invention belongs to communication technical field, relate to the wireless communication system transmission in multiple-input and multiple-output MI MO system and single carrier communication, can be applicable in wireless communication link or wireless network, improve utilance and the power system capacity of frequency band, also can be used to the traditional problem solving the Media access contorl such as the concealed terminal in wireless network.
Background technology
Along with the development of the communication technology and the sharply increase of mobile communication subscriber quantity, available communications band is more and more crowded.Expect people the message transmission rate that future communication systems can not only provide higher, and more effectively can utilize frequency spectrum resource.Take duplex mode can take the connection of point-to-point between the transmit leg of transmitting apparatus and the recipient of receiving equipment, higher data transmission bauds can be obtained.
Duplex mode in the communication technology refer to communicating pair how to realize receiving-transmitting sides to communication.In traditional wired and wireless technology, in order to prevent the interference between receiving and transmitting signal, usually adopt the duplex mode of FDD or TDD.In FDD mode, transmitting-receiving adopts different carrier frequencies or frequency range to send signal simultaneously and realizes two-way communication; TDD adopts identical carrier wave in different directions, and receiving-transmitting sides sends in the different time respectively, very frequent due to what switch between transmitting-receiving, still feels carry out real-time two-way communication at the same time to user.
These two kinds of duplex modes of FDD and TDD at one time same carrier frequency only there will be the signal of single direction, avoid the self-interference between same node receiving and transmitting signal, the realization of receiver and transmitter is comparatively simple, constitutes the basis of present communications technology transceiver.But these two kinds of technology all fail to make full use of frequency resource, technically, it is feasible that single carrier wave frequency range carries out two-way communication simultaneously, and this mode is referred to as " single carrier full-duplex communication ".Single carrier full duplex can not only utilize frequency resource more fully, and can accomplish " saying while listen ", has more advantages in wireless packet communications.
Existing in single frequency full-duplex systematic research with in realizing, the problem of major concern has two aspects: one is how to improve snr of received signal by transceiver designs, receiving loop design and digital interference elimination; Two is how can improve frequency range and transmitting power on existing scheme basis.
The people such as Stanford Univ USA Jung Choi propose to utilize placement three antennas i.e. two receipts, and the distance precisely arranged between antenna, the wireless carrier signal that two transmit antennas are sent is cancelled out each other at reception antenna place just, thus reduces the effect of strong self-interference.The Ashutosh Sabharwal team of Rice University proposes the three kinds of assembled schemes eliminated by antenna, simulation interference is eliminated and digital interference is eliminated: ASAC is eliminated in antenna+simulation, antenna+numeral eliminates ASDC, antenna+simulation+numeral eliminates ASADC, and the ideal performance of three kinds of schemes is given by analysis and simulation, the poorest interference signal that can both obtain 70dB nearly eliminates ability.
Domestic aspect, Beijing Jiaotong University is in the patent proposed " one disappears and disturbs full duplex relay communications system and full duplex the trunking " (applying date: 2010.06.11, application number: 2010205580.X, publication No.: 101882965A) in, describe and carry out echo interference elimination to the received signal by the interference module that disappears.Its interference module that disappears comprises decoder and encoder, and decoder is used for carrying out decoding to the received signal, and corresponding decoding matrix is D, and encoder is used for encoding to the signal after decoding, and corresponding encoder matrix is P, and wherein D and P meets: D
heP=0, wherein E is the echo channel matrix in relay node equipment.
These related ends show, by comprehensive utilization antenna, analogue echo bucking circuit and Digital Signal Processing, the Received signal strength entering into numeric field can to avoid flood by strong self-interference signal, thus, more advanced Digital Signal Processing can be utilized on this basis to obtain more high-transmission capacity, improve spectrum utilization efficiency.There is multiple antenna in current proposed single frequency full-duplex technology, but but can only realize transceive communications, do not make full use of the ability of multiple antennas.
Summary of the invention
The object of the invention is to based on existing self-interference technology for eliminating and MIMO technology, a kind of mimo system that can realize full-duplex communication on single carrier is provided, to improve message capacity and the availability of frequency spectrum of single frequency full-duplex system.
For achieving the above object, system of the present invention comprises: MIMO sends signal processing module 1, MIMO Received signal strength processing module 5 and N number of parallel branch, wherein N >=2, comprise digital-to-analogue conversion up-converter module (2) in each branch road, transceiver 3 and analog-to-digital conversion down conversion module 4, it is characterized in that
Echo Cancellation network 6 is connected with, for eliminating the echo reflection because the reasons such as multiple scattering cause between digital-to-analogue conversion up-converter module 2 and transceiver 3;
Strong self-interference cancellation module 7 is connected with between Echo Cancellation network 6 and analog-to-digital conversion down conversion module 4, the information of signal is sent for utilizing known this locality, strong self-interference signal between local antenna is eliminated, to make the useful signal that receives by not covered by strong signal during analog-digital converter;
Being connected with numeric field interference cancellation module 8 between analog-to-digital conversion down conversion module 4 and MIMO Received signal strength processing module 5, for utilizing the local information sending signal, the residual interference after Echo Cancellation network and strong self-interference cancellation module further being eliminated.
As preferably, described Echo Cancellation network 6 is three port analog circuit networks, the input of its first port is through the transmission analog signal of ovennodulation, second port is bidirectionally coupled to transceiver 3, this port has and sends signal output and Received signal strength input, have the reflection echo input sending signal simultaneously; Utilize Huygens's electric bridge or other Echo Cancellation circuit, by the phase place of input signal and amplitude adjustment after and reflection echo signal offset, and by Received signal strength and unmatched fall residual echo signal export through the 3rd port.
As preferably, described strong self-interference cancellation module 7, comprise digital analog converter 71, filter 72 and adder 73, after transmission signal is carried out digital-to-analogue conversion by digital analog converter 71, carry out filtering by filter 72 to this signal, filtered signal is sent to adder 73 and is added with its Received signal strength, eliminates the self-interference in Received signal strength.
As preferably, described numeric field cancellation module 8, comprise and create interference duplicate module 81, compensating module 82, sef-adapting filter 83 and adder 84, create interference duplicate module 81 and create interference replica signal according to transmission signal and interference channel information, and carry out delay compensation by compensating module 82 to this interference replica signal, signal after compensation is sent to adder 84 by sef-adapting filter 83 and is added with its Received signal strength, eliminates the residual interference in Received signal strength.
The present invention compared with prior art owing to comprehensively employing Echo Cancellation technology, self-interference technology for eliminating and numeric field interference cancellation techniques, thus can from Received signal strength excavation useful signal as much as possible, make full use of the every bit useful signal obtained; In addition, also can convert the small-signal under strong jamming background to digital signal by analog-digital converter, be convenient to receive process.
Accompanying drawing explanation
Fig. 1 is the structured flowchart of present system;
Fig. 2 is the Echo Cancellation network diagram in the present invention;
Fig. 3 is the strong self-interference cancellation module block diagram in the present invention;
Fig. 4 is the numeric field interference cancellation module block diagram in the present invention.
Embodiment
Below in conjunction with accompanying drawing, the multi-input multi-output system that the present invention is based on single carrier full duplex is described further:
With reference to Fig. 1, the present invention is based on the multi-input multi-output system of single carrier full duplex, comprise MIMO and send signal processing module 1, MIMO Received signal strength processing module 5 and N number of parallel branch, wherein N >=2, digital-to-analogue conversion up-converter module 2 is comprised in each branch road, transceiver 3, analog-to-digital conversion down conversion module 4, Echo Cancellation network 6, strong self-interference cancellation module 7 and numeric field interference cancellation module 8, wherein:
MIMO sends signal processing module 1, forms multiple branch circuit signal and exports.On every bar branch road, after transmission digital signal is converted to analog baseband signal by digital-to-analogue conversion up-converter module 2, produces through up-conversion and send analog signal, be transferred to Echo Cancellation network 6.Echo Cancellation network 6 is through being bi-directionally connected transmission analog signal transmission to transceiver 3.Transceiver 3 is connected with transmitting antenna and reception antenna, transmission analog signal is sent by transmitting antenna, and the useful Received signal strength, reflection echo signal and the adjacent antenna high reject signal that are received by reception antenna are fed to Echo cancellation network 6 together.Echo cancellation network 6 pairs of reflection echo signals are eliminated, strong self-interference cancellation module 7 is given through the 3rd port transmission by the Received signal strength after the elimination of this antenna-reflected echo-signal, strong self-interference cancellation module 7 receives the digital baseband signal sent from other branch roads simultaneously, realize being added with the interference signal in Received signal strength the function offset, Received signal strength with residual interference signal is transferred to analog-to-digital conversion down conversion module 4 by strong self-interference cancellation module 7 simultaneously, converts digital baseband signal to and enter numeric field interference cancellation module 8 after the process such as frequency conversion conversion.Numeric field interference cancellation module 8 also receives the digital baseband signal sent from other branch roads simultaneously, utilize known transmission information, further residual interference signal is eliminated, the more useful Received signal strength of each branch road is transferred to together with faint residual interference, noise signal MIMO Received signal strength processing module 5 carry out reception process.
With reference to Fig. 2, Echo Cancellation network 6 of the present invention is three port analog circuit networks, and wherein, the first port accepts sends analog signal; Second port is bidirectionally coupled to transceiver 3, this port exports and sends analog signal, inputs the mixed signal that useful Received signal strength, transmitting echo-signal and adjacent antenna high reject signal are formed; By Echo Cancellation analog circuit, offset carrying out being added with reflection echo signal after the phase place of the first port input signal and amplitude adjustment, then by Received signal strength and unmatched fall residual echo signal export through the 3rd port.
With reference to Fig. 3, strong self-interference cancellation module 7 of the present invention, comprise digital analog converter 71, filter 72 and adder 73, this module introduces the digital baseband signal sending other branch roads that signal processing module 1 sends from MIMO, by it after digital analog converter 71 converts analog signal to, then realized and the anti-phase same width of self-interference signal in the Received signal strength of Echo Cancellation by filter 72, be added with the self-interference signal in Received signal strength by adder 73 again and offset, the Received signal strength with residual interference signal exported is sent to analog-to-digital conversion down conversion module 4.
With reference to Fig. 4, numeric field interference cancellation module 8, comprise and create interference duplicate module 81, compensating module 82, sef-adapting filter 83 and adder 84, this module utilizes the interference channel information sending the digital baseband signal of other branch roads of signal processing module 1 and the formation after analogue echo is offset and strong self-interference is eliminated from MIMO, the duplicate that numeric field remains local interference signal is created by creating interference duplicate module 81, and by compensating module 82, delay compensation is carried out to this replica signal, signal after compensation is by sef-adapting filter 83 filtering, make the same width of residual interference signal inversion in itself and Received signal strength, finally send into adder 84 to be added with Received signal strength, eliminate the residual interference in Received signal strength.
MIMO in the present invention sends signal processing module 1 can use digital signal processor or FPGA programming realization, this module carries out precoding processing to information source, form multiple branch circuit signal, coded modulation is carried out to every tributary signal, insert the transmission such as frame synchronization and pilot signal auxiliary signal in the data, then carry out a series of process such as framing, obtain digital baseband signal, and be dealt in the follow-up module of each branch road after shaping filter is carried out to digital baseband signal.
Digital-to-analogue conversion up-converter module 2 in the present invention, completes by the conversion of digital baseband signal to radio-frequency transmission signals.Wherein digital analog converter can adopt but the AD9862 chip being not limited to ADI company realizes, and this chip provides digital up converter and the digital to analog converter of PLC technology interpolation rate.Digital baseband signal is after digital up converter, and export digital medium-frequency signal, digital medium-frequency signal converts the analog radio-frequency signal that can transmit in space channel to after realizing up-conversion further by being multiplied with carrier signal.
Analog-to-digital conversion down conversion module 4 in the present invention, completes by the conversion of radio-frequency transmission signals to digital baseband signal.After radio-frequency transmission signals realizes a down-conversion by being multiplied with the carrier signal that local oscillator produces, the digital down converter of analog-digital converter and PLC technology sampling rate can be adopted to obtain digital baseband signal, and wherein digital down converter can adopt but be not limited to the level Four cascade integral comb filter of programming realization in FPGA.In the present embodiment, the digital analog converter in analog-to-digital conversion frequency-variable module also can adopt AD9862 chip to realize.
Transceiver 3 in the present invention, comprises a transmitting antenna and a reception antenna, and carry out signal transmission and reception simultaneously in same carrier wave frequency range.
MI MO Received signal strength processing module 5 in the present invention adopts digital signal processor or FPGA programming realization, this module receives the multi-path digital baseband signal after eliminating interference, after baseband signal being carried out to a series of Digital Signal Processing such as digital filtering, identification, synthesis, known channel information is utilized to carry out the process of MIMO Received signal strength to each tributary signal, such as improve signal gain by maximum-ratio combing MRC technology, then realize the operations such as digital demodulation decoding and frame recovery, obtain reception information.
It is more than example of the present invention; do not form any limitation of the invention; obviously for those skilled in the art; after understanding content of the present invention and principle; all may when not deviating from the principle of the invention, structure; carry out the various correction in form and details and change, but these corrections based on inventive concept and change are still within claims of the present invention.
Claims (4)
1. the multi-input multi-output system based on single carrier full duplex, comprise MIMO and send signal processing module (1), MIMO Received signal strength processing module (5) and N number of parallel branch, wherein N >=2, digital-to-analogue conversion up-converter module (2) is comprised in each branch road, transceiver (3) and analog-to-digital conversion down conversion module (4), is characterized in that
Echo Cancellation network (6) is connected with, for eliminating the echo reflection because multiple scattering reason causes between digital-to-analogue conversion up-converter module (2) and transceiver (3);
Strong self-interference cancellation module (7) is connected with between Echo Cancellation network (6) and analog-to-digital conversion down conversion module (4), the information of signal is sent for utilizing known this locality, strong self-interference signal between local antenna is eliminated, to make the useful signal that receives by not covered by strong signal during analog-digital converter;
Being connected with numeric field interference cancellation module (8) between analog-to-digital conversion down conversion module (4) and MIMO Received signal strength processing module (5), for utilizing the local information sending signal, the residual interference after Echo Cancellation network and strong self-interference cancellation module further being eliminated;
Described Echo Cancellation network (6) is three port analog circuit networks, the input of its first port is through the transmission analog signal of ovennodulation, second port is bidirectionally coupled to transceiver (3), second port has and sends signal output and Received signal strength input, have the reflection echo input sending signal simultaneously; Utilize Huygens's electric bridge or other Echo Cancellation circuit, by the phase place of input signal and amplitude adjustment after and reflection echo signal offset, and by Received signal strength and unmatched fall residual echo signal export through the 3rd port.
2. as claimed in claim 1 based on the multi-input multi-output system of single carrier full duplex, it is characterized in that, described strong self-interference cancellation module (7) comprises digital analog converter (71), filter (72) and adder (73), after transmission signal is carried out digital-to-analogue conversion by digital analog converter (71), by filter (72), filtering is carried out to this signal, filtered signal is sent to adder (73) and is added with its Received signal strength, eliminates the self-interference in Received signal strength.
3. as claimed in claim 1 based on the multi-input multi-output system of single carrier full duplex, it is characterized in that, described numeric field cancellation module (8), comprise and create interference transcript module (81), compensating module (82), sef-adapting filter (83) and adder (84), create interference transcript module (81) and create interference copy signal according to transmission signal and interference channel information, and by compensating module (82), delay compensation is carried out to this interference copy signal, signal after compensation is sent to adder (84) by sef-adapting filter (83) and is added with its Received signal strength, eliminate the residual interference in Received signal strength.
4., as claimed in claim 1 based on the multi-input multi-output system of single carrier full duplex, it is characterized in that, described transceiver (3), same carrier wave frequency range is carried out send and Received signal strength simultaneously.
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| CN104185186B (en) * | 2013-05-23 | 2018-02-23 | 华为技术有限公司 | The suppressing method and the network equipment of signal interference |
| US9793967B2 (en) | 2013-11-21 | 2017-10-17 | The Hong Kong University Of Science And Technology | Weighted sum data rate maximization using linear transceivers in a full-duplex multi-user MIMO system |
| RU2644396C2 (en) * | 2013-11-29 | 2018-02-12 | Хуавэй Текнолоджиз Ко., Лтд. | Device and method for self-interference signal reduction in communication system |
| CN105594131B (en) * | 2013-11-29 | 2018-02-06 | 华为技术有限公司 | The method and apparatus for reducing communication system self-interference signal |
| EP3103203B1 (en) * | 2014-02-27 | 2019-06-12 | Huawei Technologies Co., Ltd. | System and method for multiple-input and multiple-output (mimo) full-duplex precoding structures |
| WO2015139266A1 (en) * | 2014-03-20 | 2015-09-24 | 华为技术有限公司 | Apparatus and method for self-interference cancellation |
| CN104378177B (en) * | 2014-11-10 | 2018-04-27 | 上海交通大学 | A kind of collision alarm restoration methods based on iteration MIMO detections |
| CN105391664A (en) * | 2015-10-16 | 2016-03-09 | 哈尔滨工业大学深圳研究生院 | Method for counteracting analog interference in long term evolution (LTE) full duplex system based on multiple-input multiple-output (MIMO) |
| CN106817134B (en) * | 2016-10-25 | 2019-04-16 | 张慧 | A kind of configurable full duplex radio network radar communication system |
| CN109768823B (en) * | 2018-12-28 | 2020-05-15 | 长沙天仪空间科技研究院有限公司 | Narrow-band multi-channel satellite communication system |
| CN112398507B (en) * | 2019-08-15 | 2022-09-23 | 华为技术有限公司 | Noise signal processing device and method |
| CN116346151A (en) * | 2021-12-15 | 2023-06-27 | 中兴通讯股份有限公司 | Communication transceiver, signal transmitting/receiving method, electronic device, and storage medium |
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