CN1996785B - Forwarding system and its method for the broadband wireless access - Google Patents

Abstract

This invention relates to one wide band wireless interface system and discloses one transfer system and its method to improve the spectrum materials utility, wireless signal capacitor and data communication speed, which firstly using OFDM technique to change the frequency selective channel into flat anneal channel to form antenna MIMO system by use of one set transfer points antenna to realize one set of mutual distribution MIMO code transmission system.

Description

The transfer system and the method thereof of broadband wireless access

Technical field

The present invention relates to BWA, particularly the transfer system and method for broadband wireless access.

Background technology

Recent years, wireless access wide band technology caused people's extensive concern, with respect to other broadband access technology, and the BWA small investment, the construction period is short, provides professional fast, has lot of advantages.International institute of electrical and electronic engineers (Institute of Electrical and ElectronicEngineers; Abbreviation " IEEE ") committee has formulated the IEEE802.16 standard for this reason specially; Propose the broadband wireless access solution, but must guarantee line-of-sight transmission, for densely populated city; Owing to there are many barriers such as high building, trees; Cause coverage very limited, so in the IEEE802.16a standard of formulating afterwards, proposed a kind of broadband wireless access solution again based on wireless interface net (Mesh) technology; Wireless Mesh netword is actually a kind of multi-multipoint network of high-capacity high speed, and it is the distributed network of a kind of novel can solving " last kilometer " bottleneck problem.The Mesh network is different from traditional wireless network; Because each user node wherein all is the part of backbone network; Can transmit the information of other user node, and along with the increase of network node, the coverage of network and flexibility can increase thereupon also.

World Interoperability for Microwave Access, WiMax (World Interoperability for Microwave Access; Be called for short " WiMAX ") be an emerging wireless communication technology; Can provide towards the high speed of the Internet to connect, be a broadband wireless access metropolitan area network technology based on 802.16 standards.The transmission of wireless signals furthest of WiMAX can reach 50 kilometers.It is used for 802.11a wireless access focus is connected to the Internet, also can link environment to wired backbone circuits such as company and family.It can be used as the wireless extensions technology of cable and user data line, thereby realizes that WiMAX inserts.

802.16 technical advantage is: the interoperability of equipment makes operator buy WiMAX equipment from a plurality of equipment manufacturers; Stable measured platform will excite the innovation of technology such as each layer, network management, antenna, thereby improve the problem of running cost; Better spectrum efficiency under the farther distance; Newly-increased sector is simple and easy, and channel plan flexibly makes capacity reach maximization, and allows operator to develop into the basis expansion network that comes to upgrade gradually according to the user; Channel width planning flexibly meets the needs of the frequency allocation situation of the frequency range of license, and does not need the frequency allocation situation of the frequency range of license; To hundreds of user, medium Access Layer agreement keeps distribution mechanism efficiently from unique user; Various advanced technologies are improved the non line of sight performance; Outstanding system gain provides the stronger obstacle ability that penetrates at a distance.

Wireless access network is by NMS (Network Management System; Abbreviation " NMS "), base station controller (Base Station Contriller; Abbreviation " BSC "), base station (BaseStation; Be called for short " BS ") and subscriber station (Subscriber Station is called for short " SS ") composition.In the BRAN structure based on the Mesh technology, all BS and SS are called node.BS links to each other with other backbone network, realizes broadband access; The SS node both can have been realized local user's broadband access, can transmit the data of other node again, was sent to destination node to these data, and effect is similar to a transit node.In the Mesh network, also can direct communication between the SS, and can be through other SS indirect communication between BS and the SS.Be called the neighbor node of this node with the node that a node directly links to each other, the distance between them is called " one jumps ".Each node in the network all possesses routing function, and each node only communicates with adjacent node, therefore is a kind of self-organizing and the network managed certainly.In fact; The Mesh network more similarly is a kind of wireless version of Internet itself; Grouped data is routed to another route from one and transmits up to arriving its destination, and these characteristics make Mesh network and traditional cellular communications networks and fixed communication network that remarkable difference arranged.

For BRAN, when number of users increases,, increased the coverage of network potentially because each subscriber station can be used as a transit node based on the Mesh structure.Concerning operator, adopt wireless Mesh netword to have the following advantages: network coverage increases, the availability of frequency spectrum improves, power system capacity increases; The distinctive multirouting selectivity characteristic of Mesh network configuration has improved the pliability and the availability of network, when mistake appears in certain paths, can select other path; Network has scalability, is prone to dilatation, the initial stage construction cost is low, cost of investment approximately is 15% of a PMP network; Investment risk is less relatively, and be that recoverable cost obtains profit within a short period of time.In a word, this technology compared with traditional point-to-multipoint have such as energy-conservation, dispose and a lot of advantages such as easy dilatation automatically, a lot of companies have begun that this technology is used for broadband network and have inserted, and relevant products such as wireless router have also begun commercialization.

Multiple-input and multiple-output (Multi Input Multi Output is called for short " MIMO ") and space division multiplexing (Space Division Multiplex is called for short " SDM ") are one of forward position communication technologys of current development.Verified in theory, adopt a plurality of transmitting antennas to be divided into a plurality of parallel narrow band channels to wireless channel, have the potential that improves the channel bit transfer rate, and result of study shows that channel capacity increases and linear the increase with antenna amount.Compare with smart antenna with receive diversity, mimo system not only can provide diversity gain and the gain of battle array row, and can adopt the mode of spatial reuse to improve power system capacity.

Structure during dblast (Bell LAboratory Space-Time architecture is called for short " BLAST ") is to adopt space multiplexing technique to improve a kind of approach of bandwidth availability in the radio communication.The BLAST system utilizes a plurality of antennas to send parallel data flow simultaneously in same frequency range, and utilize abundant multipath transmisstion different data flow, and can separate at receiver, thus the space diversity of obtaining.Its principle is that a plurality of transmitters adopt identical modulation system, and a plurality of receivers also adopt identical demodulation mode.BLAST is divided into many substreams to the data flow of unique user, and utilizes a plurality of antennas to send these parallel son stream simultaneously, and all son streams send in same frequency band, so the frequency spectrum service efficiency is very high.Desired data has a plurality of copies to get into channel (transmitting antenna), and a plurality of outputs (reception antenna) are arranged simultaneously.At receiver end; A plurality of antennas are picked out a plurality of substream of data and the scattering copy thereof that sends; All substream of data that send that each reception antenna " visible " is superimposed; Utilize complicated signal processing technology, the difference through these subchannels can mask data stream and is detected.

Because transmitter still is the antenna number of receiver all is limited, therefore increasing diversity gain is a pair of contradiction with improving emission rate.Empty time-code (Space Time Code is called for short " STC ") and empty sign indicating number frequently (Space Frequency Code is called for short " SFC ") can solve this contradiction preferably.

The space diversity that empty time-code has utilized multiaerial system to provide, its performance depends on the antenna number and the coding of signal on room and time of system, and is most representative like Space-Time Block Coding and space-time grid code.Non-multipath channel condition has all been supposed in the design of these yards, belongs to the arrowband sign indicating number, and maximum obtainable diversity gain equals the product of number of transmit antennas and reception antenna number.Under the multipath channel condition of broadband, the performance of empty time-code is not best, because it has only utilized space diversity, and fails the channel frequency diversity of utilizing multipath to provide.Studying under the multi-path environment; Based on OFDM (Orthogonal FrequencyDivision Multiplex; The encoded question of multiaerial system abbreviation " OFDM "); Proposed the notion of empty frequency sign indicating number, the potential diversity gain that can realize of these yards is the product of number of transmit antennas, reception antenna number and channel impulse response length (channel multi-path number).

From the coherence time and the coherence bandwidth of fading channel, empty time-code require a code block crossing over several OFDM characters in the cycle channel fading keep approximate constant time response, promptly be the bigger the better coherence time; And empty sign indicating number frequently requires the channel fading frequency response of a code block of several number of sub-carrier of leap to keep approximate constant, and promptly coherence bandwidth is the bigger the better.See that from constraints empty time-code has better performance in flat fading channel, and empty sign indicating number frequently has better performance in fast fading channel.But in fact; Transmitter can't be foreseen channel condition information; Can integrate empty time-code and the empty advantage of sign indicating number frequently for this reason, adopt space-time frequency code (Space Time Frequency Code is called for short " STFC ") scheme; On spatial domain, time-domain and frequency domain, unite consideration, thereby realized the maximum diversity gain under many antennas fading channel.

For STFC, SFC and STC, can be divided into block code (Block Code is called for short " BC ") and grid code (Trellis Code is called for short " TC ") again.

Empty time-code is primarily aimed at flat fading channel, and the characteristic of channel is generally frequency selective fading in actual high speed data transmission system.OFDM (OFDM) technology can be divided into a plurality of parallel relevant flat fading channels to frequency selective fading channels, thereby presents non-frequency selective fading on each carrier wave.802.16 with empty time-code and orthogonal frequency division multiplexi combination utilization.

IEEE 802.16 is first broadband wireless access standard, mainly contains two versions: the broadband fixed wireless of 802.16 standards inserts version, and the broadband mobile wireless of " 802.16-2004 " and 802.16 standards inserts version, " 802.16e ".802.16-2004 only defined two kinds of network elements, BS and SS; 802.16e also only defined two kinds of network elements, BS and mobile subscriber station (Mobile SS is called for short " MSS ").Present 802.16 multi-hop transfer seminar (Multihop Relay SG) have only proposed WiMAX transit node (Relay Station; Abbreviation " RS ") notion; One of them important effect is as the transfer between BS and SS/MSS, increases the throughput of subscriber station.

What must solve based on the wireless access system of transfer is that source node arrives each transit node and the multiplexing problem from each transit node to destination node; Usually can only adopt two kinds of prior aries: frequency division multiplexing, BS takies different frequency ranges respectively with each transit node between SS/MSS; Time division multiplexing, each transit node between BS and SS/MSS uses identical frequency range, but takies the different time section.Technical disadvantages according to frequency division multiplexing is: spectrum requirement broad, frequency spectrum are the rare resource of operator, and the frequency spectrum resource waste is bigger.Conversely according to time-multiplexed technical disadvantages: spectrum requirement is few; But for subscriber station; Owing to the necessary time-sharing work of each transit node, reduced the average data traffic rate of each transit node, the throughput of subscriber station increases limited even possibly reduce on the contrary.

In practical application, there is following problem in such scheme:

Cause the main cause of this situation to be, a plurality of transit nodes adopt conventional communication techniques such as frequency division multiplexing or time division multiplexing.

Summary of the invention

In view of this; Main purpose of the present invention is to provide a kind of transfer system and method thereof of broadband wireless access; Make frequency spectrum resource utilization rate, wireless channel capacity and data communication rates be improved; Link reliability and stability improve, and anti-interference and antimierophonic performance is enhanced.

For realizing above-mentioned purpose, the invention provides a kind of transfer system of broadband wireless access, comprise source node, transit node, destination node, wherein,

Said transit node will be forwarded to destination node from the wireless communication data of source node through MIMO technique;

Said source node is used to indicate said transit node to carry out multiple-input and multiple-output communication;

Said destination node is used to receive and decode from the wireless communication data of said transit node.

Wherein, comprise at least two said transit nodes, form the transit node group of helping each other, each transit node comprises at least one transmitting antenna, a reception antenna, and the antenna of all transit nodes is formed the antenna sets of multiple-input and multiple-output communication.

In this external said system, source node is used for directly giving said transit node with data broadcasting;

Said transit node comprises distributed multiple-input and multiple-output coding unit; The receiver of said transit node is used to receive the data from source node, and the transmitter of each transit node is used for the counterpart through the data behind the distributed multiple-input and multiple-output coding is sent to destination node;

Destination node obtains communication data with corresponding decoding technique.

In this external said system; Source node is used for data are carried out corresponding multiple-input and multiple-output coding; And, the different coding part of multiple-input and multiple-output coding is sent to corresponding transit node on each orthogonal sub-channels according to the different transmit antennas of different help each other transit node and the different transit nodes of helping each other;

The receiver of each transit node is used to receive on the corresponding subchannel data from source node;

The transmitter of all transit nodes is used for the data that receive separately parallel destination node that sends on same subchannel;

Destination node obtains communication data with corresponding decoding technique.

In this external said system, comprise at least two said transit nodes, form at least the two-stage transit node group of helping each other, each transit node comprises at least one transmitting antenna, a reception antenna; Arbitrarily the help each other antenna of the transit node that the transit node group comprised of one-level is formed the antenna sets of multiple-input and multiple-output communication.

In this external said system, source node is used for directly data broadcasting to the first order transit node group of helping each other;

The first order transit node transit node that group comprises of helping each other comprises distributed multiple-input and multiple-output coding unit; Its receiver is used to receive the data from source node; And encode by its distributed multiple-input and multiple-output coding unit, its transmitter be used for through the data forwarding behind the distributed multiple-input and multiple-output coding to the second level transit node group of helping each other;

The transit node that any one-level comprises that the second level to afterbody is helped each other in the transit node group all comprises distributed multiple-input and multiple-output coding unit and multiple-input and multiple-output decoding unit; Its receiver is used to receive from the help each other data of transit node group of upper level; And decode by its multiple-input and multiple-output decoding unit; Encoded by its distributed multiple-input and multiple-output coding unit, its transmitter is used for the counterpart through the data behind the distributed multiple-input and multiple-output coding is sent to next stage help each other transit node group or destination node again;

Destination node obtains communication data with corresponding decoding technique.

In this external said system; Source node is used for data are carried out corresponding multiple-input and multiple-output coding; And, the different coding part of multiple-input and multiple-output coding is sent to the first order corresponding transit node that the transit node group comprised of helping each other on each orthogonal sub-channels according to the help each other different transmit antennas of transit node of the first order different help each other transit node and first order difference;

The help each other receiver of transit node transit node that group comprises of the first order is used on corresponding subchannel, receiving the data from source node, and its transmitter is used for the data that receive parallel second level transit node group of helping each other that sends on same subchannel;

The transit node that any one-level comprises that the second level to afterbody is helped each other in the transit node group all comprises distributed multiple-input and multiple-output coding unit and multiple-input and multiple-output decoding unit; Its receiver is used on same subchannel receiving from the help each other data of transit node group of upper level; And decode by its multiple-input and multiple-output decoding unit; Encoded by its distributed multiple-input and multiple-output coding unit, its transmitter is used for through the counterpart of the data behind the distributed multiple-input and multiple-output coding parallel next stage help each other transit node group or the destination node of sending on same subchannel again;

Destination node obtains communication data with corresponding decoding technique.

In this external said system, said subchannel is any one in OFDM subchannel, time-division subchannel, the sign indicating number branch subchannel.

In this external said system, the said distributed multiple-input and multiple-output coding unit that said transit node comprised and said multiple-input and multiple-output decoding unit adopt when empty, empty frequently, in empty time-frequency or the layering spatial reuse coding and decoding technology any one.

In this external said system, the transmitter of said source node, transit node, destination node all adopts the OFDM modulation technique, and receiver all adopts the OFDM demodulation techniques.

In this external said system, the receiver of said transit node comprises at least one group of OFDM demodulator, symbol de-maps unit, channel-decoding unit, reception antenna.

In this external said system, the receiver with transit node of multiple-input and multiple-output decoding function comprises at least one group of OFDM demodulator, symbol de-maps unit, channel-decoding unit, space-time/space-frequency/empty time-frequency/spatial reuse decoding unit, reception antenna;

Wherein, said units is by receiving signal flow to pressing following any one sequence arrangement successively:

Reception antenna, OFDM demodulator, symbol de-maps unit, channel-decoding unit, space-time/space-frequency/empty time-frequency/spatial reuse decoding unit;

Reception antenna, OFDM demodulator, symbol de-maps unit, space-time/space-frequency/empty time-frequency/spatial reuse decoding unit, channel-decoding unit;

Reception antenna, OFDM demodulator, space-time/space-frequency/empty time-frequency/spatial reuse decoding unit, symbol de-maps unit, channel-decoding unit;

Perhaps, reception antenna, space-time/space-frequency/empty time-frequency/spatial reuse decoding unit, OFDM demodulator, symbol de-maps unit, channel-decoding unit.

In this external said system, the transmitter with transit node of distributed multiple-input and multiple-output encoding function comprises at least one group of orthogonal frequency division multiplexing modulator, sign map unit, chnnel coding unit, distributed space time/space-frequency/empty time-frequency/spatial reuse coding unit, transmitting antenna;

Wherein, said units flows to successively by following any one sequence arrangement by transmitting:

Distributed space time/space-frequency/empty time-frequency/spatial reuse coding unit, chnnel coding unit, sign map unit, orthogonal frequency division multiplexing modulator, transmitting antenna;

Chnnel coding unit, distributed space time/space-frequency/empty time-frequency/spatial reuse coding unit, sign map unit, orthogonal frequency division multiplexing modulator, transmitting antenna;

Chnnel coding unit, sign map unit, distributed space time/space-frequency/empty time-frequency/spatial reuse coding unit, orthogonal frequency division multiplexing modulator, transmitting antenna;

Perhaps, chnnel coding unit, sign map unit, orthogonal frequency division multiplexing modulator, distributed space time/space-frequency/empty time-frequency/spatial reuse coding unit, transmitting antenna.

The present invention also provides a kind of middle shifting method of broadband wireless access, comprises step,

Source node sends to all transit nodes with wireless communication data;

All transit nodes will be forwarded to destination node from the wireless communication data of source node with MIMO technique;

Said destination node receives and decodes from the wireless communication data of said transit node.

Wherein, at least two said transit nodes are formed the transit node group of helping each other, and each transit node comprises at least one transmitting antenna, a reception antenna, and the antenna of all transit nodes is formed the antenna sets of multiple-input and multiple-output communication.

In this external said method, also comprise step,

Source node is directly given said transit node with data broadcasting;

Said transit node receives the data from source node, and carries out distributed multiple-input and multiple-output coding, and each transit node sends to destination node with its counterpart then.

In this external said method, also comprise step,

Source node carries out corresponding multiple-input and multiple-output coding to data; And, the different coding part of multiple-input and multiple-output coding is sent to corresponding transit node on each orthogonal sub-channels according to the different transmit antennas of different help each other transit node and the different transit nodes of helping each other;

Each transit node receives on the corresponding subchannel data from source node;

The data that all transit nodes will receive separately are the parallel destination node that sends on same subchannel.

In this external said method, at least two said transit nodes are formed at least the two-stage transit node group of helping each other, and each transit node comprises at least one transmitting antenna, a reception antenna; Arbitrarily the help each other antenna of the transit node that the transit node group comprised of one-level is formed the antenna sets of multiple-input and multiple-output communication.

In this external said method, also comprise step,

Source node directly with data broadcasting to the first order transit node group of helping each other;

The first order is helped each other the transit node group of received from the data of source node, and carries out distributed multiple-input and multiple-output coding, is transmitted to the second level transit node group of helping each other again;

Help each other any one-level in the transit node group of the second level to afterbody is helped each other the transit node group of received from the help each other data of transit node group of upper level; Carry out the multiple-input and multiple-output decoding earlier; Carry out distributed multiple-input and multiple-output coding again, the counterpart of data of will encode then afterwards sends to next stage help each other transit node group or destination node.

In this external said method; Source node carries out corresponding multiple-input and multiple-output coding to data; And according to the different first order help each other transit node and the different first order help each other in the different transmit antennas of trochanter, the different coding part of multiple-input and multiple-output coding is sent to the first order corresponding transit node that the transit node group comprised of helping each other on each orthogonal sub-channels;

The first order transit node transit node that group comprises of helping each other receives the data from source node on corresponding subchannel, and with the data that receive parallel second level transit node group of helping each other that sends on same subchannel;

The second level to afterbody any one-level in transit node group transit node group of helping each other of helping each other receives on same subchannel from the help each other data of transit node group of upper level; And carry out multiple-input and multiple-output and decode; Carry out distributed multiple-input and multiple-output coding again, the counterpart that will pass through the data behind the distributed multiple-input and multiple-output coding then is parallel next stage help each other transit node group or the destination node of sending on same subchannel.

In this external said method, said subchannel is any one in OFDM subchannel, time-division subchannel, the sign indicating number branch subchannel.

In this external said method, said multiple-input and multiple-output decode procedure, when distributed multiple-input and multiple-output cataloged procedure adopts sky respectively, empty frequently, in empty time-frequency or the layering spatial reuse coding and decoding technology any one.

Through relatively finding; The main distinction of technical scheme of the present invention and prior art is; At first utilize the OFDM technology that frequency-selective channel is become flat fading channel; Thereby can constitute the mimo system of many antennas through all antennas that utilize one group of transit node, thereby realize advanced technologies such as space division multiplexing;

The inner system configuration of transit node can realize the distributed MIMO encoding and decoding transmission system (wherein the ground floor transit node also can only carry out the distributed MIMO coding) of one group of transit node of helping each other; Can adopt space-time/space-frequency/empty time-frequency/spatial reuse coding method, make full use of the advantage of space division multiplexing;

The multiple input multiple output between the superior and the subordinate of single-stage or multistage transit node group has been realized the MIMO transmission of multi-hop transfer.

Difference on this technical scheme; Brought comparatively significantly beneficial effect; Promptly use a plurality of antennas to carry out distributed multiple-input and multiple-output (MIMO) technology of transfer of data helping each other between transit node group and destination node, through spatial reuse (SDM), as on original frequency range, having set up a plurality of subchannels that do not disturb mutually, walk abreast; Avoid different transit nodes all will apply for different frequency ranges; Can under the situation that does not increase bandwidth and antenna transmission power, improve the availability of frequency spectrum exponentially, and then improve wireless channel capacity, power system capacity and data communication rates exponentially.

Adopt MIMO to constitute multiplex (MUX) and can resist channel fading to a certain extent, less because a plurality of channel is in the possibility of deep fade simultaneously, thus improve link reliability.

Empty time-code, empty sign indicating number, space-time frequency code technology frequently combine coding techniques and antenna array technology; Space diversity, time diversity and frequency diversity have been realized; Improved anti-fading (particularly anti-frequency selective fading) performance of system, and can two-forty is provided, realize high-quality transfer of data through emission diversity gain and receive diversity gain.Compare with the coded system of not using the blending space technology, the blending space coding can obtain higher coding gain under the situation of not sacrificing bandwidth, and then has improved anti-interference and antimierophonic ability.

When transit node and subscriber station during all only with single transmit and reception antenna, system is the simplest, and cost is minimum, and it is technological but to use the common MIMO that must the many antennas of unit just can accomplish, is very suitable for the application scenarios of subscriber station as transit node.

Description of drawings

Fig. 1 is the single-hop of the first embodiment of the invention transfer system configuration sketch map of helping each other;

Fig. 2 realizes principle schematic according to the single-hop of the 3rd execution mode of the present invention OFDM of the transfer system subchannel of helping each other;

Fig. 3 realizes principle schematic according to help each other transfer system time-division subchannel of the single-hop of the 3rd execution mode of the present invention;

Fig. 4 divides subchannel to realize principle schematic according to the single-hop of the 3rd execution mode of the present invention transfer systematic code of helping each other;

Fig. 5 is according to the multi-hop of the 4th execution mode of the present invention transfer system configuration sketch map of helping each other;

Fig. 6 realizes principle schematic according to the multi-hop of the 6th execution mode of the present invention OFDM of the transfer system subchannel of helping each other;

Fig. 7 realizes principle schematic according to help each other transfer system time-division subchannel of the multi-hop of the 6th execution mode of the present invention;

Fig. 8 divides subchannel to realize principle schematic according to the multi-hop of the 6th execution mode of the present invention transfer systematic code of helping each other;

Fig. 9 is the transit node receiver structure sketch map according to the 8th execution mode of the present invention;

Figure 10 is the transit node receiver structure sketch map according to the no MIMO receiving function of the 8th execution mode of the present invention;

Figure 11 is the transit node transmitter architecture sketch map according to the 9th execution mode of the present invention;

Figure 12 is the simple transfer system configuration sketch map according to the tenth execution mode of the present invention.

Embodiment

For making the object of the invention, technical scheme and advantage clearer, will combine accompanying drawing that the present invention is done to describe in detail further below.

The present invention utilizes mutual-aid team of a plurality of antennas compositions of a plurality of transit nodes in the transfer wireless access system; Unite and (for example realize distributed MIMO technology and space encoding and decoding technique; The combination of layering spatial reuse sign indicating number, empty time-code, empty sign indicating number frequently or space-time frequency code), thus can on the basis of existing equipment condition, make full use of the technological advantage of sky branch such as MIMO uses in the field in the such forward position of broadband wireless access.Realize that through the sky that the uses MIMO technology of dividing a plurality of transit nodes insert the technology of same destination node; Support subscriber station to walk abreast transit node to insert same base station simultaneously with frequency through a plurality of parallel transit nodes or multi-hop; Can solve the problem of the spectrum requirement broad of prior art, the throughput that can solve subscriber station again increases problem limited even that possibly reduce on the contrary.

The present invention realizes the MIMO communication of the transit node group of helping each other through distributed MIMO codec unit (wherein the ground floor transit node can only be provided with the distributed MIMO coding unit) is set at each transit node.And in all net element communications, adopt the OFDM transmit-receive technology, and make the frequency selectivity fast fading channel become parallel flat fading channel, make the MIMO technology be able to practical application.In addition; Help each other MIMO communication between the transit node group of the superior and the subordinate is generalized to this system the situation of multi-hop transfer in multi-hop transfer system; In one-level MIMO communicates by letter arbitrarily; The channel of each transit node can be divided dual mode through direct method and subchannel and realize, its sub-channels is divided modes such as can dividing subchannel again according to OFDM subchannel, time-division subchannel, sign indicating number and implemented.At last, this paper has provided a simple execution mode with the explanation practical situations.

Basic innovation of the present invention is the MIMO technology implementation on a plurality of antennas of a plurality of transit nodes.Based on this, can be divided into two kinds of systems of single-hop and multi-hop again, these two kinds of systems do not have essential distinction.Every kind of system can be divided into direct method and subchannel method etc. by the superior and the subordinate's communication mode again; All adopt the ofdm communication technology for every kind of situation; Therefore the transceiver of each transit node and source node destination node has all been realized the OFDM technology, also comprises aforementioned distributed MIMO codec unit and other functional units in addition.

The first embodiment of the present invention is the single-hop transfer system model of helping each other, and is as shown in Figure 1.Comprise source node, one group of node such as transit node group, destination node of helping each other that transit node constitutes.Communicating by letter between source node and destination node done the parallel transfer of helping each other by a plurality of transit nodes.Transit node will be forwarded to destination node from the wireless communication data of source node with the MIMO technology.

Each transit node comprises at least one transmitting antenna, a reception antenna, and all transit nodes comprise the distributed MIMO codec unit, and the antenna of all transit nodes is formed the antenna sets of MIMO communication.As shown in the figure, transit node 1, transit node 2 ..., transit node N constitutes the transit node group of helping each other; Help each other a transit node group and a distributed MIMO system of a destination node formation; Promptly help each other transit node i (i=1 ..., T N) _iIndividual transmitting antenna is as the T of mimo channel _iIndividual input, the then total T=(T of mimo channel ₁+ T ₂+ ...+T _i+ ...+T _N) individual input, the R of destination node reception antenna receives R output of mimo channel.

The first embodiment of the present invention based on communicating method between the source node of distributed MIMO technology and destination node, three steps are arranged: source node sends to all transit nodes with wireless communication data; All transit nodes will be forwarded to destination node from the wireless communication data of source node with the MIMO technology; Destination node receives and decodes from the wireless communication data of transit node.Also can be divided into two stages: broadcasting stage and transfer stage.The broadcasting stage just is meant the step of will the transmission wireless communication data issuing each transit node of helping each other from source node; The transfer stage is exactly that the transit node group of helping each other is transmitted to the step of destination node with the MIMO technology.

On the basis of first embodiment, adopt direct method to realize two above-mentioned stages, the broadcasting stage: source node is directly given transit node with data broadcasting in the second embodiment of the present invention; The transfer stage: transit node receives the data from source node, and when carrying out distributed space, empty frequently, empty time-frequency or layering spatial reuse coding, each transit node sends to destination node with its counterpart then.

In the broadcasting stage: each the transit node broadcasting identical information sequence S of source node in the transit node group of helping each other.

In the transfer stage: the identical information sequence S of transit node 1...N to receiving that help each other, carry out distributed Space Time Coding (or space-frequency coding or space-time frequency coding or layering spatial reuse coding) respectively; Help each other transit node i (i=1 ..., N) form (T in the Matrix C ₁+ T ₂+ ...+T _I-1+ 1) row is to (T ₁+ T ₂+ ...+T _i) capable T altogether _iRow coded identification, wherein T ₀=0, the result of the transit node distribution type of helping each other coding forms a unified Space Time Coding (or space-frequency coding or space-time frequency coding or layering spatial reuse coding) sign matrix C:

$C=\left[\begin{array}{cccc}{c}_{11}& c_{12}& \mathrm{\&Lambda;}& c_{1s}\\ c_{21}& c_{22}& \mathrm{\&Lambda;}& c_{2s}\\ M& M& O& M\\ c_{m1}& {\mathrm{<figure-callout\; id="2"\; label="c\; m"\; filenames="H06105286820060209E000012.png,H06105286820060209E000032.png"\; state="\{\{state\}\}">c</figure-callout>}}_m& \mathrm{\&Lambda;}& c_{\mathrm{ms}}\end{array}\right]$

Wherein, the line number of matrix is m=T (by the number of transmit antennas decision of the transit node group of helping each other), and matrix column is counted s and then depended on concrete coding method; Then, the capable symbol of the T of coded identification matrix is from the T=(T of the transit node group of helping each other ₁+ T ₂+ ...+T _i+ ...+T _N) individual transmitting antenna, through T * R mimo channel, send to destination node respectively.

At last, destination node is carried out space-time/space-frequency/empty time-frequency/spatial reuse decoding to the received signal, obtains burst S.

In fact, the communication meeting between above-mentioned each transit node of broadcasting stage is overlapped, therefore also can replace direct broadcasting law through the method that takies subchannel separately.

The third embodiment of the present invention on the basis of first embodiment, when source node carries out sky to data, empty frequently, empty time-frequency or layering spatial reuse coding, and on each subchannel, send to corresponding transit node; Each transit node receives on the corresponding subchannel data from source node, and when carrying out distributed space, empty frequently, empty time-frequency or layering spatial reuse coding; The data of all transit nodes after with each own coding are the parallel destination node that sends on same subchannel.Here each subchannel has solved the overlapping collision problem of a plurality of transit nodes, but has only used a subchannel in the parallel MIMO communication of helping each other, and does not therefore reduce power system capacity and the speed of MIMO.

Here the subchannel of mentioning can be existing multiple mode, and such as the subchannel of OFDM subchannel, time-multiplexed subchannel, code division multiplexing, following mask body provides the ins and outs that this three subchannel is implemented.

Fig. 2 shows the realization principle of OFDM subchannel method, suppose the OFDM channel by sub carrier group i (i=1 ...; N) difference is divided 1...N the OFDM subchannel (subchannel) that is orthogonal, OFDM subchannel i (i=1; ...; N) distribute to source node to the transit node i that helps each other (i=1 ..., communication port N).

In the broadcasting stage, at first, source node carries out space-time/space-frequency/empty time-frequency/spatial reuse coding to source signal sequence S, forms space-time/space-frequency/empty time-frequency/spatial reuse coded identification Matrix C; Source node through OFDM subchannel i (i=1 ..., N), (T among the sending metrix C ₁+ T ₂+ ...+T _I-1+ 1) row is to (T ₁+ T ₂+ ...+T _i) capable T altogether _iThe space encoding symbol of row is to the transit node i that helps each other.Wherein, T ₀=0.

In the transfer stage, each node of the transit node group of helping each other can take whole OFDM channel, to improve transmission data rate; The transit node group of helping each other with each row space coded identification of space encoding sign matrix C, is sent to destination node respectively simultaneously through T transmitting antenna.That is, the transit node 1 of helping each other passes through T ₁Individual transmitting antenna is gone the 1st in the Matrix C to T respectively ₁Row is T altogether ₁The space encoding symbol of row is sent to destination node simultaneously; Help each other transit node 2 through T2 transmitting antenna, respectively with the (T in the Matrix C ₁+ 1) row is to (T ₁+ T ₂) capable T altogether ₂The space encoding symbol of row is sent to destination node simultaneously; By that analogy, the transit node i that helps each other passes through T _iIndividual transmitting antenna is respectively with the (T in the Matrix C ₁+ T ₂+ ...+T _I-1+ 1) row is to (T ₁+ T ₂+ ...+T _i) capable T altogether _iThe space encoding symbol of row is sent to destination node simultaneously; The transit node N that helps each other passes through T _NIndividual transmitting antenna is respectively with the (T in the Matrix C ₁+ T ₂+ ...+T _N-1+ 1) row is to (T ₁+ T ₂+ ...+T _N) capable T altogether _NThe space encoding symbol of row is sent to destination node simultaneously.

At last, destination node is carried out space-time/space-frequency/empty time-frequency/spatial reuse decoding to the received signal, obtains burst S.

Fig. 4 shows the realization principle of time-division subchannel method, suppose communication channel press time slot i (i=1 ..., difference N); Divide 1...N the time-division subchannel that is orthogonal, time-division subchannel i (i=1 ...; N) distribute to source node to the transit node i that helps each other (i=1 ..., communication port N).

In the broadcasting stage, at first, source node carries out space-time/space-frequency/empty time-frequency/spatial reuse coding to source signal sequence S, forms space-time/space-frequency/empty time-frequency/spatial reuse coded identification Matrix C; Source node through time-division subchannel i (i=1 ..., N), (T among the sending metrix C ₁+ T ₂+ ...+T _I-1+ 1) row is to (T ₁+ T ₂+ ...+T _i) the capable capable space encoding symbol of Ti altogether, to the transit node i that helps each other.Wherein, T ₀=0.

In the transfer stage, each node of the transit node group of helping each other can take time-division subchannel 0, to improve transmission data rate; The transit node group of helping each other with each row space coded identification of space encoding sign matrix C, is sent to destination node at time-division subchannel 1 respectively through T transmitting antenna.That is, the transit node 1 of helping each other passes through T ₁Individual transmitting antenna is gone the 1st in the Matrix C to T respectively ₁Row is T altogether ₁The space encoding symbol of row is sent to destination node at time-division subchannel 1; Help each other transit node 2 through T2 transmitting antenna, respectively with the (T in the Matrix C ₁+ 1) row is to (T ₁+ T ₂) capable T altogether ₂The space encoding symbol of row is sent to destination node at time-division subchannel 1; By that analogy, the transit node i that helps each other passes through T _iIndividual transmitting antenna is respectively with the (T in the Matrix C ₁+ T ₂+ ...+T _I-1+ 1) row is to (T ₁+ T ₂+ ...+T _i) capable T altogether _iThe space encoding symbol of row is sent to destination node at time-division subchannel 1; The transit node N that helps each other passes through T _NIndividual transmitting antenna is respectively with the (T in the Matrix C ₁+ T ₂+ ...+T _N-1+ 1) row is to (T ₁+ T ₂+ ...+T _N) capable T altogether _NThe space encoding symbol of row is sent to destination node at time-division subchannel 1.

At last, destination node is carried out space-time/space-frequency/empty time-frequency/spatial reuse decoding to the received signal, obtains burst S.

Fig. 5 shows the realization principle of yard molecule channel method, suppose communication channel press spreading code i (i=1 ..., difference N); Divide 1...N the spread spectrum subchannel that is orthogonal, spreading code i (i=1 ...; N) distribute to source node to the transit node i that helps each other (i=1 ..., communication port N).

In the broadcasting stage, at first, source node carries out space-time/space-frequency/empty time-frequency/spatial reuse coding to source signal sequence S, forms space-time/space-frequency/empty time-frequency/spatial reuse coded identification Matrix C; Source node press spreading code i (i=1 ..., N) the spread spectrum, (T among the sending metrix C ₁+ T ₂+ ...+T _I-1+ 1) row is to (T ₁+ T ₂+ ...+T _i) capable T altogether _iThe space encoding symbol of row is to the transit node i that helps each other.Wherein, T0=0.

In the transfer stage, each node of the transit node group of helping each other can adopt same spreading code (like spreading code 0) spread spectrum, to improve transmission data rate; The transit node group of helping each other with each row space coded identification of space encoding sign matrix C, by same spreading code (like spreading code 1), is sent to destination node respectively simultaneously through T transmitting antenna.That is, the transit node 1 of helping each other passes through T ₁Individual transmitting antenna is gone the 1st in the Matrix C to T respectively ₁Row is T altogether ₁The space encoding symbol of row by same spreading code (like spreading code 0) spread spectrum, is sent to destination node simultaneously; The transit node 2 of helping each other passes through T ₂Individual transmitting antenna is respectively with the (T in the Matrix C ₁+ 1) row is to (T ₁+ T ₂) capable T altogether ₂The space encoding symbol of row by same spreading code (like spreading code 0) spread spectrum, is sent to destination node simultaneously; By that analogy, the transit node i that helps each other passes through T _iIndividual transmitting antenna is respectively with the (T in the Matrix C ₁+ T ₂+ ...+T _I-1+ 1) row is to (T ₁+ T ₂++ T _i) capable T altogether _iThe space encoding symbol of row by same spreading code (like spreading code 0) spread spectrum, is sent to destination node simultaneously; The transit node N that helps each other passes through T _NIndividual transmitting antenna is respectively with the (T in the Matrix C ₁+ T ₂+ ...+T _N-1+ 1) row is to (T ₁+ T ₂+ ...+T _N) capable T altogether _NThe space encoding symbol of row, same spreading code (like spreading code 0) spread spectrum is sent to destination node simultaneously.

At last, destination node is carried out space-time/space-frequency/empty time-frequency/spatial reuse decoding to the received signal, obtains burst S.

Certain above-mentioned single-hop transfer system that helps each other can easily be generalized to the situation of multi-hop; The fourth embodiment of the present invention is exactly the multi-hop of similar first embodiment transfer system that helps each other; This system comprises a plurality of transit nodes and forms the multistage transit node group of helping each other, and each transit node comprises a plurality of dual-mode antennas; Arbitrarily the one-level transit node that the transit node group comprised of helping each other comprises the distributed MIMO codec unit, and the help each other antenna of the transit node that the transit node group comprised of one-level is formed the antenna sets of MIMO communication arbitrarily.

Fig. 5 shows this multi-hop transfer system model of helping each other, communicating by letter between source node and destination node by the multistage transit node group of helping each other, and the every grade of transit node group of helping each other is done the parallel transfer of helping each other by a plurality of transit nodes.Like Fig. 6, transit node 1, transit node 2 ..., transit node M _kConstitute the transit node group of helping each other; The transit node that every grade of help each other transit node group and next stage are helped each other in the transit node group can both constitute a distributed MIMO system; Then constitute a distributed MIMO system for the afterbody transit node group of helping each other with destination node; The help each other T of transit node i of every k level _{K, i}Individual transmitting antenna is as the T of corresponding mimo channel _{K, i}Individual input, the then total T of corresponding M IMO channel _k=(T _{K, 1}+ T _{K, 2}+ ...+T _{K, i}+ ...+T _{K, Mk}) individual input, the R of next stage (i.e. k+1 level) the transit node j that helps each other _{(k+1), j}Individual (or the R of destination node) reception antenna receives the R of mimo channel _{(k+1), j}(or R) individual output.

In like manner, corresponding implementation method also is generalized to the situation of multi-hop.The fourth embodiment of the present invention based on communicating method between the source node of distributed MIMO technology and destination node, different with single-hop is: the one-level transit node that the transit node group comprised of helping each other comprises the distributed MIMO codec unit arbitrarily; Arbitrarily the help each other antenna of the transit node that the transit node group comprised of one-level is formed the antenna sets of MIMO communication; One-level all receives from upper level arbitrarily, through issuing next stage behind the decoding and coding.Broadcasting stage and a plurality of transfer stage are equally also arranged, and the number in the transfer stage also number with the transit node group is identical, is: broadcasting stage, transfer stage 1 ..., transfer stage N.

In like manner broadcasting stage and transfer stage specifically also is divided into direct method and several kinds of schemes of subchannel method, and the fifth embodiment of the present invention adopts direct method to realize above-mentioned several stages on the basis of the 4th embodiment.

In the broadcasting stage: each the transit node broadcasting identical information sequence S of source node in the 1st grade of transit node group of helping each other.

1: the transfer stage, 1 grade of transit node 1...M that helps each other ₁To the identical information sequence S that receives, carry out distributed Space Time Coding (or space-frequency coding or space-time frequency coding or layering spatial reuse coding) respectively, the 1st grade of transit node i that helps each other forms (the T in the Matrix C _1,1+ T _1,2+ ...+T _{1, i-1}+ 1) row is to (T _1,1+ T _1,2+ ...+T _{1, i}) capable T altogether _{1, i}Row coded identification, the result of the 1st grade of transit node distribution type coding of helping each other are to form a unified Space Time Coding (or space-frequency coding or space-time frequency coding or layering spatial reuse coding) sign matrix C ₁, wherein the line number of matrix is T ₁(by the number of transmit antennas decision of the 1st grade of transit node group of helping each other), the matrix column number then depends on concrete coding method; Then, the T of coded identification matrix ₁The row symbol is from T ₁=(T _1,1+ T _1,2+ ...+T _{1, i}+ ...+T _{1, M1}) individual transmitting antenna, be sent to the 2nd grade of transit node j that helps each other through mimo channel.

2: the transfer stages, 2 grades of transit node 1...M that help each other ₂Carry out distributed decoding (or empty decoding frequently or the decoding of empty time-frequency or the decoding of layering spatial reuse) when empty respectively; The 2nd grade of transit node 1...M that helps each other then ₂To the identical information sequence S that receives; Carry out Space Time Coding (or space-frequency coding or space-time frequency coding or layering spatial reuse coding) respectively, the result of the 2nd grade of transit node distribution type coding of helping each other forms a unified Space Time Coding (or space-frequency coding or space-time frequency coding or layering spatial reuse coding) sign matrix C ₂, wherein the line number of matrix is T ₂(by the number of transmit antennas decision of the 2nd grade of transit node group of helping each other), the matrix column number then depends on concrete coding method; Then, the T of coded identification matrix ₂The row symbol is from T ₂=(T _2,1+ T _2,2+ ...+T _{2, i}+ ...+T _{2, M2}) individual transmitting antenna, send the 3rd level transit node j that helps each other respectively through mimo channel.

The rest may be inferred, transfer stage k: the k level transit node 1...M that helps each other _kCarry out distributed decoding (or empty decoding frequently or the decoding of empty time-frequency or the decoding of layering spatial reuse) when empty respectively, each k level transit node of helping each other all will obtain source node through the help each other information sequence S of transit node group transfer of k-1 level; The k level transit node 1...M that helps each other then _kTo the identical information sequence S that receives; Carry out Space Time Coding (or space-frequency coding or space-time frequency coding or layering spatial reuse coding) respectively, the help each other result of transit node distribution type coding of k level forms a unified Space Time Coding (or space-frequency coding or space-time frequency coding or layering spatial reuse coding) sign matrix C _k, wherein the line number of matrix is T _k(by the help each other number of transmit antennas decision of transit node group of k level), the matrix column number then depends on concrete coding method; Then, the T of coded identification matrix _kThe row symbol is from T _k=(T _{K, 1}+ T _{K, 2}+ ...+T _{K, i}+ ...+T _{K, Mk}) individual transmitting antenna, send the k+1 level transit node j that helps each other respectively through mimo channel.

Afterbody, transfer stage N: N level (afterbody) the transit node 1...M that helps each other _nCarry out distributed decoding (or empty decoding frequently or the decoding of empty time-frequency or the decoding of layering spatial reuse) when empty respectively, each N level transit node of helping each other all will obtain source node through the help each other information sequence S of transit node group transfer of N-1 level; The N level transit node 1...M that helps each other then _nTo the identical information sequence S that receives; Carry out Space Time Coding (or space-frequency coding or space-time frequency coding or layering spatial reuse coding) respectively, the help each other result of transit node distribution type coding of N level forms a unified Space Time Coding (or space-frequency coding or space-time frequency coding or layering spatial reuse coding) sign matrix C _n, wherein the line number of matrix is T _n(by the help each other number of transmit antennas decision of transit node group of N level), the matrix column number then depends on concrete coding method; Then, the T of coded identification matrix _nThe row symbol is from T _n=(T _{N, 1}+ T _{N, 2}+ ...+T _{N, i}+ ...+T _{N, Mn}) individual transmitting antenna, send to destination node respectively through mimo channel.

At last, destination node is carried out space-time/space-frequency/empty time-frequency/spatial reuse decoding to the received signal, obtains burst S.

The sixth embodiment of the present invention adopts the subchannel method to realize above-mentioned several stages on the basis of the 4th embodiment.

When source node carries out sky to data, empty frequently, empty time-frequency or layering spatial reuse coding, and on each subchannel, send to the first order corresponding transit node that the transit node group comprised of helping each other;

Arbitrarily one-level help each other on the corresponding subchannel of transit node group of received from source node or upper level help each other the transit node group data and decode, when carrying out distributed space then, empty frequently, empty time-frequency or layering spatial reuse coding;

Arbitrarily one-level each transit node of transit node group counterpart of data of will encode afterwards of helping each other sends to next stage help each other transit node group or destination node on corresponding subchannel; Afterbody will the encode counterpart parallel destination node that sends on same subchannel of back data of each transit node that the transit node group comprises of helping each other wherein.

The realization of OFDM subchannel, time-division subchannel, sign indicating number molecule channel three kind situation can be arranged equally.

Fig. 6 is a multihop system OFDM subchannel implementation sketch map, supposes that the OFDM channel is by sub carrier group i (i=1..., difference N); Divide 1...N the OFDM subchannel (subchannel) that is orthogonal; OFDM subchannel i (i=1 ..., N) distribute to 1 grade of source node to the transit node i (i=1 that helps each other; ..., communication port N).

In the broadcasting stage, at first, source node carries out space-time/space-frequency/empty time-frequency/spatial reuse coding to source signal sequence S, forms space-time/space-frequency/empty time-frequency/spatial reuse coded identification Matrix C ₁Source node through OFDM subchannel i (i=1 ..., N), sending metrix C ₁In (T _1,1+ T _1,2+ ...+T _{1, i-1}+ 1) row is to (T _1,1+ T _1,2+ ...+T _{1, i}) capable T altogether ₁, the space encoding symbol that i is capable is to the 1st grade of transit node i that helps each other.Wherein, T _1,0=0.

1: the transfer stage, 1 grade of each node of transit node group of helping each other can take whole OFDM channel or take same subchannel, to improve transmission data rate; The 1st grade of transit node group of helping each other passed through T ₁Individual transmitting antenna is respectively with space encoding sign matrix C ₁Each row space coded identification, be sent to the 2nd grade of transit node j that helps each other; Transfer stage 2-N: 2-N level each node of transit node group of helping each other can take whole OFDM channel, perhaps takies same subchannel.

Fig. 7 is a multihop system time-division subchannel schematic diagram.Suppose communication channel press time slot i (i=1 ..., difference N) is divided 1...N time-division subchannel being orthogonal, time-division subchannel i (i=1 ..., N) distribute to 1 grade of source node to the help each other transit node i (i=1 ..., communication port N).

In the broadcasting stage, at first, source node carries out space-time/space-frequency/empty time-frequency/spatial reuse coding to source signal sequence S, forms space-time/space-frequency/empty time-frequency/spatial reuse coded identification Matrix C ₁Source node through time-division subchannel i (i=1..., N), sending metrix C ₁In (T _1,1+ T _1,2+ ...+T _{1, i-1}+ 1) row is to (T _1,1+ T _1,2+ ...+T _{1, i}) capable T altogether _{1, i}The space encoding symbol of row is to the 1st grade of transit node i that helps each other.Wherein, T _1,0=0.

In the transfer stage, the 1st grade of each node of transit node group of helping each other can take time-division subchannel 1, to improve transmission data rate; The 1st grade of transit node group of helping each other passed through T ₁Individual transmitting antenna is respectively with space encoding sign matrix C ₁Each row space coded identification, be sent to destination node at time-division subchannel 1; Transfer stage 2-N: k (k=2 ..., N) level help each other each node of transit node group can take time-division subchannel k (k=2 ..., N).

Fig. 8 divides the subchannel schematic diagram for the multihop system sign indicating number.Suppose communication channel press spreading code i (i=1 ..., difference N) is divided 1...N spread spectrum subchannel being orthogonal, spreading code i (i=1 ..., N) distribute to 1 grade of source node to the help each other transit node i (i=1 ..., communication port N).

In the broadcasting stage, at first, source node carries out space-time/space-frequency/empty time-frequency/spatial reuse coding to source signal sequence S, forms space-time/space-frequency/empty time-frequency/spatial reuse coded identification Matrix C ₁Source node press spreading code i (i=1 ..., N) spread spectrum, sending metrix C ₁In (T _1,1+ T _1,2+ ...+T _{1, i-1}+ 1) row is to (T _1,1+ T _1,2+ ...+T _{1, i}) capable T altogether _{1, i}The space encoding symbol of row is to the 1st grade of transit node i that helps each other.Wherein, T _1,0=0.

In the transfer stage, the 1st grade of each node of transit node group of helping each other can adopt same spreading code (like spreading code 0) spread spectrum, to improve transmission data rate; The 1st grade of transit node group of helping each other passed through T ₁Individual transmitting antenna is respectively with space encoding sign matrix C ₁Each row space coded identification, by same spreading code (like spreading code 1), be sent to destination node simultaneously; Transfer stage 2-N: k (k=2 ..., N) level help each other each node of transit node group can adopt same spreading code (as spreading code k (k=2 ..., N)) spread spectrum.

Set forth each transit node inner implementation and formation thereof below.The seventh embodiment of the present invention adopts the OFDM technology on the basis of the foregoing description, so all websites: the transmitter of source node, transit node, destination node all adopts the OFDM modulation technique, and receiver all adopts the OFDM demodulation techniques.Empty time-code is primarily aimed at flat fading channel, and the characteristic of channel is generally frequency selective fading in actual high speed data transmission system.OFDM (OFDM) technology can be divided into a plurality of parallel relevant flat fading channels to frequency selective fading channels, thereby presents non-frequency selective fading on each carrier wave.802.16 with empty time-code and orthogonal frequency division multiplexi combination utilization.

In the above-described embodiments; Reception and forwarding step all need carry out the distributed encoding and decoding of MIMO basically; Only notice and jump in the transit node group of helping each other, need not carry out the MIMO decoding during reception, because at this moment source node only is directly to broadcast in the first order or first of direct method.In addition, the receiver section of the transmitter section of all transit nodes, other grades or other implementations all need use the distributed codec unit of MIMO.

Therefore, eighth embodiment of the invention is on the basis of the 7th embodiment, and the receiver section of transit node all comprises reception antenna, ofdm demodulator, symbol de-maps unit, channel-decoding unit, space-time/space-frequency/empty time-frequency/spatial reuse decoding unit.It is that one tunnel joint is merged in the multiple signals decoding from a plurality of reception antennas that its hollow is decomposed code element, and the unit that therefore is positioned at before this unit all is that each branch road all has corresponding cells, is positioned at then to have only a unit after this unit.

For i transit node to T should be arranged _iIndividual transmit/receive antenna, the transit node group of helping each other has T=(T ₁+ T ₂+ ...+T _i+ ...+T _M) individual transmitting antenna; The transit node group of helping each other forms space-time/space-frequency/empty time-frequency/spatial reuse sign matrix C jointly; Wherein the line number of matrix is T; Then help each other transit node i to carrying out distributed space time/space-frequency/empty time-frequency/spatial reuse encoding and decoding, form (the T in the Matrix C from the/signal of going to OFDM reception/transmitter ₁+ T ₂+ ...+T _I-1+ 1) row is to (T ₁+ T ₂+ ...+T _i) capable T altogether _iThe row coded identification, Here it is, and distributed space divides MIMO encoding and decoding principle.

Divide the residing position of decoding unit different according to sky, four kinds of schemes can be arranged, promptly press signal flow to following arrangement:

Reception antenna, ofdm demodulator, symbol de-maps unit, channel-decoding unit, space-time/space-frequency/empty time-frequency/spatial reuse decoding unit, therefore empty branch decoding unit in the end is called source bits level receiver;

Therefore reception antenna, ofdm demodulator, symbol de-maps unit, space-time/space-frequency/empty time-frequency/spatial reuse decoding unit, channel-decoding unit, the empty decoding unit that divides were called the superfine receiver of channel ratio before channel-decoding;

Reception antenna, ofdm demodulator, space-time/space-frequency/empty time-frequency/spatial reuse decoding unit, symbol de-maps unit, channel-decoding unit, therefore the empty decoding unit that divides was called source symbol level receiver before channel-decoding and symbol de-maps;

Perhaps, reception antenna, space-time/space-frequency/empty time-frequency/spatial reuse decoding unit, ofdm demodulator, symbol de-maps unit, channel-decoding unit, therefore empty branch decoding unit is called channel symbol level receiver up front.

The decoding least unit of bit-level decoder is a bit, and the decoding least unit of symbol level decoder is a symbol.Such as the third situation, the decoding least unit can be the symbol before quadrature amplitude modulation (QuadratureAmplitude Modulation is called for short " QAM ") symbol de-maps; The coding least unit can be the OFDM symbol before the OFDM demodulation in the 4th kind of situation.The receiver structure sketch map of above-mentioned four kinds of situation provides in Fig. 9 kind.

But the front is mentioned; All need carry out the empty decoding of dividing under not all situation; Above-mentioned situation is applicable to: source node adopts the help each other terminal (or multi-hop help each other the 1st grade of terminal of transfer system) of transfer system of the single-hop of Space Time Coding (or space-frequency coding or space-time frequency coding or layering spatial reuse coding) technology, perhaps multi-hop non-the 1st grade of terminal of transfer system of helping each other.And source node does not adopt the help each other terminal (or multi-hop help each other the 1st grade of terminal of transfer system) of transfer system of the single-hop of Space Time Coding (or space-frequency coding or space-time frequency coding or layering spatial reuse coding) technology; Then do not need the sky in the said structure to divide decoding unit; Promptly only have: reception antenna, ofdm demodulator, symbol de-maps unit, channel-decoding unit; Therefore there are not four kinds of different putting in order yet; And having only one road signal, comparison diagram 9 provides its structure such as Figure 10 easily.

In like manner; For transmitter; Only be that signal flow is to difference; General configuration is basic identical, and nineth embodiment of the invention is on the basis of the 7th embodiment, and the transmitter section of transit node all comprises transmitting antenna, OFDM modulator, sign map unit, chnnel coding unit, space-time/space-frequency/empty time-frequency/spatial reuse coding unit.Same empty to divide coding unit be the place that one road signal is divided into multichannel, and the unit that therefore is positioned at after this unit all is that each branch road all has corresponding cells, is positioned at then to have only a unit before this unit.

Divide the residing position of coding unit different according to sky, four kinds of schemes can be arranged, promptly press signal flow to following arrangement:

Space-time/space-frequency/empty time-frequency/spatial reuse coding unit, chnnel coding unit, sign map unit, OFDM modulator, transmitting antenna, therefore empty branch coding unit in the end is called source bits level transmitter;

Therefore chnnel coding unit, space-time/space-frequency/empty time-frequency/spatial reuse coding unit, sign map unit, OFDM modulator, transmitting antenna, the empty coding unit that divides were called the superfine transmitter of channel ratio before chnnel coding;

Chnnel coding unit, sign map unit, space-time/space-frequency/empty time-frequency/spatial reuse coding unit, OFDM modulator, transmitting antenna, therefore the empty coding unit that divides was called source symbol level transmitter before chnnel coding and sign map;

Perhaps, chnnel coding unit, sign map unit, OFDM modulator, space-time/space-frequency/empty time-frequency/spatial reuse coding unit, transmitting antenna, therefore empty branch coding unit is called channel symbol level transmitter up front.

The transmitter architecture sketch map of above-mentioned four kinds of situation provides in Figure 11.

At last, provide the single-hop transfer system embodiment of simple two transit nodes, the system model of ten embodiment of the present invention is shown in figure 12.Suppose to have between base station and subscriber station two terminals 1 and 2 to constitute help each other transit node group, wherein h _SjBe the multidiameter fading channel time-domain response of base station to terminal j (j=1,2); h _JdBe the multidiameter fading channel time-domain response of terminal j (j=1,2) to subscriber station.

Two terminal transmitters of helping each other respectively have 1 transmit antennas; Be at least λ/2 (λ is a wavelength) apart; Promptly sending the process that signal propagates in different paths should be able to be thought separate attenuation process at the subscriber station receiving terminal 1 reception antenna is arranged by approximate, and decoder needs the single output of many inputs (Multi Input Single Output during this scheme subscriber station receiver empty; Abbreviation " MISO ") channel estimating, MISO also belongs to a kind of special MIMO technology in a broad sense.

Is s by the base station to the paired OFDM symbol of terminal emission _i(i=1,2), the paired OFDM symbol that receives at terminal j (j=1,2) is r _1jAnd r _2j:

r ₁₁＝h _s1s ₁+n ₁₁

r ₂₁＝h _s1s ₂+n ₂₁

r ₁₂＝h _s2s ₁+n ₁₂

r ₂₂＝h _s2s ₂+n ₂₂

Wherein, n _1jAnd n _2jBe the additive white noise of base station to terminal j (j=1,2) communication channel.

Suppose to help each other the transit node group by following when empty Matrix C carry out Space Time Coding, promptly coding result is the 1st row of Matrix C during terminal 1 distributed space, coding result is the 2nd row of Matrix C during terminal 2 distributed spaces.At moment t, terminal 1 emission r ₁₁, terminal 2 emission-r* ₂₂At moment t+1, terminal 1 emission r ₂₁, terminal 2 emission r* ₁₂

$C=\left[\begin{array}{cc}{c}_1& c_2\\ -{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="H06105286820060209E000012.png,H06105286820060209E000032.png"\; state="\{\{state\}\}">c</figure-callout>}}_2^{*}& {\mathrm{<figure-callout\; id="1"\; label="c"\; filenames="H06105286820060209E000012.png,H06105286820060209E000032.png"\; state="\{\{state\}\}">c</figure-callout>}}_1^{*}\end{array}\right]=\left[\begin{array}{cc}{r}_{11}& r_{21}\\ -r_{22}^{*}& r_{12}^{*}\end{array}\right]$

Then the paired OFDM symbol that receives of subscriber station is:

${\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="H06105286820060209E000012.png,H06105286820060209E000032.png"\; state="\{\{state\}\}">r</figure-callout>}}_1=h_{1d}{r}_{11}-h_{2d}{r}_{22}^{*}+{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="H06105286820060209E000012.png,H06105286820060209E000032.png"\; state="\{\{state\}\}">n</figure-callout>}}_1$

${\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="H06105286820060209E000012.png,H06105286820060209E000032.png"\; state="\{\{state\}\}">r</figure-callout>}}_2=h_{1d}{r}_{21}+h_{2d}{r}_{12}^{*}+{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="H06105286820060209E000012.png,H06105286820060209E000032.png"\; state="\{\{state\}\}">n</figure-callout>}}_2$

Promptly

$\left[\begin{array}{c}{r}_1\\ {\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="H06105286820060209E000012.png,H06105286820060209E000032.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^{*}\end{array}\right]=H\left[\begin{array}{c}{s}_1\\ {\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="H06105286820060209E000012.png,H06105286820060209E000032.png"\; state="\{\{state\}\}">s</figure-callout>}}_2^{*}\end{array}\right]+\left[\begin{array}{c}{N}_1\\ {\mathrm{<figure-callout\; id="2"\; label="N"\; filenames="H06105286820060209E000012.png,H06105286820060209E000032.png"\; state="\{\{state\}\}">N</figure-callout>}}_2^{*}\end{array}\right]$

Wherein, (*) expression complex conjugate, n _jBe the additive white noise of terminal j (j=1,2) to the subscriber station communications channel,

$H=\left[\begin{array}{cc}{H}_1& -H_2\\ {\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="H06105286820060209E000012.png,H06105286820060209E000032.png"\; state="\{\{state\}\}">H</figure-callout>}}_2^{*}& {\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="H06105286820060209E000012.png,H06105286820060209E000032.png"\; state="\{\{state\}\}">H</figure-callout>}}_1^{*}\end{array}\right]$

H ₁＝h _s1h _1d

${\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="H06105286820060209E000012.png,H06105286820060209E000032.png"\; state="\{\{state\}\}">H</figure-callout>}}_2={\mathrm{<figure-callout\; id="2"\; label="h\; s"\; filenames="H06105286820060209E000012.png,H06105286820060209E000032.png"\; state="\{\{state\}\}">h</figure-callout>}}_s^2{h}_{2d}$

${\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="H06105286820060209E000012.png,H06105286820060209E000032.png"\; state="\{\{state\}\}">N</figure-callout>}}_1=h_{1d}{n}_{11}+h_{2d}{n}_{22}^{*}+{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="H06105286820060209E000012.png,H06105286820060209E000032.png"\; state="\{\{state\}\}">n</figure-callout>}}_1$

${\mathrm{<figure-callout\; id="2"\; label="N"\; filenames="H06105286820060209E000012.png,H06105286820060209E000032.png"\; state="\{\{state\}\}">N</figure-callout>}}_2=h_{1d}{n}_{21}+h_{2d}{n}_{12}^{*}+{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="H06105286820060209E000012.png,H06105286820060209E000032.png"\; state="\{\{state\}\}">n</figure-callout>}}_2.$

Pass through channel estimating thus, subscriber station just can correctly receive from the signal of source station through transfer.Thus it is clear that, in theory,, on the basis of existing equipment, can realize the transfer wireless access system of high power capacity, high reliability, two-forty through OFDM of the present invention, MIMO, transfer technology.

Those of ordinary skill in the art are appreciated that; In the description of the foregoing description for concrete lively description technique details; Quote some specific example, parameter, setting and solution in the practical application; But under other practical application scenes, can adopt various feasible alternative schemes, this does not influence essence of the present invention and scope.

Claims (19)

1. the transfer system of a broadband wireless access is characterized in that, comprises source node, transit node, destination node, wherein,

Said transit node will be forwarded to destination node from the wireless communication data of source node through MIMO technique; Wherein, at least two said transit nodes are formed the transit node group of helping each other, and each transit node comprises at least one transmitting antenna, a reception antenna, and the antenna of all transit nodes is formed the antenna sets of multiple-input and multiple-output communication;

Said source node is used to indicate said transit node to carry out multiple-input and multiple-output communication;

Said destination node is used to receive and decodes from the wireless communication data of said transit node;

Wherein, source node is used for directly giving said transit node with data broadcasting; Said transit node comprises distributed multiple-input and multiple-output coding unit; The receiver of said transit node is used to receive the data from source node, and the transmitter of each transit node is used for the counterpart through the data behind the distributed multiple-input and multiple-output coding is sent to destination node; Destination node obtains communication data with corresponding decoding technique;

Perhaps; Source node is used for data are carried out corresponding multiple-input and multiple-output coding; And, the different coding part of multiple-input and multiple-output coding is sent to corresponding transit node on each orthogonal sub-channels according to the different transmit antennas of different help each other transit node and the different transit nodes of helping each other; The receiver of each transit node is used to receive on the corresponding subchannel data from source node; The transmitter of all transit nodes is used for the data that receive separately parallel destination node that sends on same subchannel; Destination node obtains communication data with corresponding decoding technique.

2. the transfer system of broadband wireless access according to claim 1 is characterized in that, comprises at least two said transit nodes, forms at least the two-stage transit node group of helping each other, and each transit node comprises at least one transmitting antenna, a reception antenna; Arbitrarily the help each other antenna of the transit node that the transit node group comprised of one-level is formed the antenna sets of multiple-input and multiple-output communication.

3. the transfer system of broadband wireless access according to claim 2 is characterized in that, source node is used for directly data broadcasting to the first order transit node group of helping each other;

The first order transit node transit node that group comprises of helping each other comprises distributed multiple-input and multiple-output coding unit; Its receiver is used to receive the data from source node; And encode by its distributed multiple-input and multiple-output coding unit, its transmitter be used for through the data forwarding behind the distributed multiple-input and multiple-output coding to the second level transit node group of helping each other;

The transit node that any one-level comprises that the second level to afterbody is helped each other in the transit node group all comprises distributed multiple-input and multiple-output coding unit and multiple-input and multiple-output decoding unit; Its receiver is used to receive from the help each other data of transit node group of upper level; And decode by its multiple-input and multiple-output decoding unit; Encoded by its distributed multiple-input and multiple-output coding unit, its transmitter is used for the counterpart through the data behind the distributed multiple-input and multiple-output coding is sent to next stage help each other transit node group or destination node again;

Destination node obtains communication data with corresponding decoding technique.

4. the transfer system of broadband wireless access according to claim 2; It is characterized in that; Source node is used for data are carried out corresponding multiple-input and multiple-output coding; And, the different coding part of multiple-input and multiple-output coding is sent to the first order corresponding transit node that the transit node group comprised of helping each other on each orthogonal sub-channels according to the help each other different transmit antennas of transit node of the first order different help each other transit node and first order difference;

The help each other receiver of transit node transit node that group comprises of the first order is used on corresponding subchannel, receiving the data from source node, and its transmitter is used for the data that receive parallel second level transit node group of helping each other that sends on same subchannel;

The transit node that any one-level comprises that the second level to afterbody is helped each other in the transit node group all comprises distributed multiple-input and multiple-output coding unit and multiple-input and multiple-output decoding unit; Its receiver is used on same subchannel receiving from the help each other data of transit node group of upper level; And decode by its multiple-input and multiple-output decoding unit; Encoded by its distributed multiple-input and multiple-output coding unit, its transmitter is used for through the counterpart of the data behind the distributed multiple-input and multiple-output coding parallel next stage help each other transit node group or the destination node of sending on same subchannel again;

Destination node obtains communication data with corresponding decoding technique.

5. the transfer system of broadband wireless access according to claim 1 is characterized in that, said subchannel is any one in OFDM subchannel, time-division subchannel, the sign indicating number branch subchannel.

6. according to the transfer system of any described broadband wireless access in the claim 1 to 4; It is characterized in that, the said distributed multiple-input and multiple-output coding unit that said transit node comprised and said multiple-input and multiple-output decoding unit adopt when empty, empty frequently, in empty time-frequency or the layering spatial reuse coding and decoding technology any one.

7. the transfer system of broadband wireless access according to claim 6 is characterized in that, the transmitter of said source node, transit node, destination node all adopts the OFDM modulation technique, and receiver all adopts the OFDM demodulation techniques.

8. the transfer system of broadband wireless access according to claim 1 is characterized in that, the receiver of said transit node comprises at least one group of OFDM demodulator, symbol de-maps unit, channel-decoding unit, reception antenna.

9. the transfer system of broadband wireless access according to claim 7; It is characterized in that the receiver with transit node of multiple-input and multiple-output decoding function comprises at least one group of OFDM demodulator, symbol de-maps unit, channel-decoding unit, space-time/space-frequency/empty time-frequency/spatial reuse decoding unit, reception antenna;

Wherein, said units is by receiving signal flow to pressing following any one sequence arrangement successively:

Reception antenna, OFDM demodulator, symbol de-maps unit, channel-decoding unit, space-time/space-frequency/empty time-frequency/spatial reuse decoding unit;

Reception antenna, OFDM demodulator, symbol de-maps unit, space-time/space-frequency/empty time-frequency/spatial reuse decoding unit, channel-decoding unit;

Reception antenna, OFDM demodulator, space-time/space-frequency/empty time-frequency/spatial reuse decoding unit, symbol de-maps unit, channel-decoding unit;

Perhaps, reception antenna, space-time/space-frequency/empty time-frequency/spatial reuse decoding unit, OFDM demodulator, symbol de-maps unit, channel-decoding unit.

10. the transfer system of broadband wireless access according to claim 7; It is characterized in that the transmitter with transit node of distributed multiple-input and multiple-output encoding function comprises at least one group of orthogonal frequency division multiplexing modulator, sign map unit, chnnel coding unit, distributed space time/space-frequency/empty time-frequency/spatial reuse coding unit, transmitting antenna;

Wherein, said units flows to successively by following any one sequence arrangement by transmitting:

Distributed space time/space-frequency/empty time-frequency/spatial reuse coding unit, chnnel coding unit, sign map unit, orthogonal frequency division multiplexing modulator, transmitting antenna;

Chnnel coding unit, distributed space time/space-frequency/empty time-frequency/spatial reuse coding unit, sign map unit, orthogonal frequency division multiplexing modulator, transmitting antenna;

Chnnel coding unit, sign map unit, distributed space time/space-frequency/empty time-frequency/spatial reuse coding unit, orthogonal frequency division multiplexing modulator, transmitting antenna;

Perhaps, chnnel coding unit, sign map unit, orthogonal frequency division multiplexing modulator, distributed space time/space-frequency/empty time-frequency/spatial reuse coding unit, transmitting antenna.

11. the middle shifting method of a broadband wireless access is characterized in that, comprises step,

Source node sends to all transit nodes with wireless communication data;

All transit nodes will be forwarded to destination node from the wireless communication data of source node with MIMO technique; Wherein, at least two said transit nodes are formed the transit node group of helping each other, and each transit node comprises at least one transmitting antenna, a reception antenna, and the antenna of all transit nodes is formed the antenna sets of multiple-input and multiple-output communication;

Said destination node receives and decodes from the wireless communication data of said transit node;

Wherein, source node is directly given said transit node with data broadcasting; Said transit node receives the data from source node, and carries out distributed multiple-input and multiple-output coding, and each transit node sends to destination node with its counterpart then;

Perhaps; Source node carries out corresponding multiple-input and multiple-output coding to data; And, the different coding part of multiple-input and multiple-output coding is sent to corresponding transit node on each orthogonal sub-channels according to the different transmit antennas of different help each other transit node and the different transit nodes of helping each other; Each transit node receives on the corresponding subchannel data from source node; The data that all transit nodes will receive separately are the parallel destination node that sends on same subchannel.

12. the middle shifting method of broadband wireless access according to claim 11 is characterized in that, at least two said transit nodes are formed at least the two-stage transit node group of helping each other, and each transit node comprises at least one transmitting antenna, a reception antenna; Arbitrarily the help each other antenna of the transit node that the transit node group comprised of one-level is formed the antenna sets of multiple-input and multiple-output communication.

13. the middle shifting method of broadband wireless access according to claim 12 is characterized in that, also comprises step,

Source node directly with data broadcasting to the first order transit node group of helping each other;

The first order is helped each other the transit node group of received from the data of source node, and carries out distributed multiple-input and multiple-output coding, is transmitted to the second level transit node group of helping each other again;

Help each other any one-level in the transit node group of the second level to afterbody is helped each other the transit node group of received from the help each other data of transit node group of upper level; Carry out the multiple-input and multiple-output decoding earlier; Carry out distributed multiple-input and multiple-output coding again, the counterpart of data of will encode then afterwards sends to next stage help each other transit node group or destination node.

14. the middle shifting method of broadband wireless access according to claim 12; It is characterized in that; Source node carries out corresponding multiple-input and multiple-output coding to data; And according to the different first order help each other transit node and the different first order help each other in the different transmit antennas of trochanter, the different coding part of multiple-input and multiple-output coding is sent to the first order corresponding transit node that the transit node group comprised of helping each other on each orthogonal sub-channels;

The first order transit node transit node that group comprises of helping each other receives the data from source node on corresponding subchannel, and with the data that receive parallel second level transit node group of helping each other that sends on same subchannel;

The second level to afterbody any one-level in transit node group transit node group of helping each other of helping each other receives on same subchannel from the help each other data of transit node group of upper level; And carry out multiple-input and multiple-output and decode; Carry out distributed multiple-input and multiple-output coding again, the counterpart that will pass through the data behind the distributed multiple-input and multiple-output coding then is parallel next stage help each other transit node group or the destination node of sending on same subchannel.

15. the middle shifting method of broadband wireless access according to claim 11 is characterized in that, said subchannel is any one in OFDM subchannel, time-division subchannel, the sign indicating number branch subchannel.

16. middle shifting method according to any described broadband wireless access in the claim 11 to 15; It is characterized in that, said multiple-input and multiple-output decode procedure, when distributed multiple-input and multiple-output cataloged procedure adopts sky respectively, empty frequently, in empty time-frequency or the layering spatial reuse coding and decoding technology any one.

17. a transit node is characterized in that, comprising:

Receiver is used at the subchannel corresponding to this transit node, receives a coded portion of multiple-input and multiple-output coding from source node;

Transmitter is used for receiving that from said source node data send to destination node at the subchannel of appointment, has other transit node on the subchannel of this appointment at least at parallel other coded portion that sends said multiple-input and multiple-output coding.

18. transit node according to claim 17 is characterized in that, said subchannel is any one in OFDM subchannel, time-division subchannel, the sign indicating number branch subchannel.

19. the middle shifting method of a broadband wireless access is characterized in that, may further comprise the steps:

Receive a coded portion of multiple-input and multiple-output coding from source node;

To receive that data send to destination node at the subchannel of appointment from said source node, have other transit node on the subchannel of this appointment at least at parallel other coded portion that sends said multiple-input and multiple-output coding.

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