CN1964217B - A multicarrier MIMO system and its communication method - Google Patents
A multicarrier MIMO system and its communication method Download PDFInfo
- Publication number
- CN1964217B CN1964217B CN2005101156249A CN200510115624A CN1964217B CN 1964217 B CN1964217 B CN 1964217B CN 2005101156249 A CN2005101156249 A CN 2005101156249A CN 200510115624 A CN200510115624 A CN 200510115624A CN 1964217 B CN1964217 B CN 1964217B
- Authority
- CN
- China
- Prior art keywords
- user
- launching beam
- signal
- multicarrier
- receiving terminal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Radio Transmission System (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
The provided multi-carrier MIMO communication system comprises: a sending end to send data frame included at least channel estimation signal and user data; and at least one receiving end to receive data frame and generate relative feedback signal and analyze data user. Wherein, the sending end generates scheduling information contained target user and code flow and appointed emission beam according to said feedback signal for adaptive user scheduling. This invention can provide maximal channel capacity, and reduces cost and algorithm complexity.
Description
Technical field
The present invention relates to the wireless communication technology of using multi-input multi-output antenna system, particularly relate to a kind of multicarrier MIMO communication system and communication means thereof.
Background technology
Following wireless communication system need be supported the very data service of two-forty, such as video conference, video request program, looks recreation or the like alternately.According to the requirement of mentioning in the ITU-R M1645 file: high-speed radio business (High Mobility), need to support to be up to the speed of 100Mbps, and, more need to reach the speed of 1Gbps for low speed (LowMobility) or fixed wireless (Fixed Wireless) business.
The speed of a channel equals the product of the spectrum efficiency of the spectral bandwidth of this channel and its application technology in the radio communication.In order to improve speed, need to improve its spectral bandwidth or the spectrum efficiency of institute's application technology.Yet frequency resource is limited, so can not unrestrictedly increase traffic rate by increasing spectral bandwidth, best method is the spectrum efficiency that increases institute's application technology.
Usually, can improve spectrum efficiency by two approach.A kind of approach is to wait the spectrum efficiency that improves link level by the technology of physical layer such as advanced person's coding techniques, signal processing technology.Another kind of approach is that the control by high level reaches resource allocation more flexibly and realizes system-level spectrum efficiency.(Multiple Input Multiple Output is corresponding two kinds of methods that realize these targets MIMO) with based on channel user dispatching method (Channel-Aware User Scheduling) to MIMO technique.Accidental beam shaping is a kind of method that is used for improving user's dispatching patcher performance, and it can be united the method for these two different agreement layers more effectively, thereby realizes the optimization of systematic function.Yet, modern communication system is all based on honeycomb, basic communication pattern is that a base station in the honeycomb is that (Mobile Station MS) provides service to a lot of users, this access problem-multi-access mode (Multiple Access) with regard to relating to the multi-user simultaneously.Traditional access way has FDMA, TDMA and CDMA, and they all are based on circuit switching (Circuit Switch) principle, and promptly each user gives and distributed a fixing frequency band (FDMA), time slot (TDMA) or spreading code (CDMA).
With GSM is example, and base station method with fixing time slot allocation in the channel of a 200K communicates to 8 time slot allocation of a frame 8 users.The advantage of this method is exactly the delay character that can guarantee communication service, relatively is suitable for this class of voice communication business relatively more responsive to time delay.Its shortcoming is that fixed resource distributes the radio channel state when not considering telex network.Because the variation of wireless channel is very big, if the user has been assigned to channel when its channel is in deep fade, will cause systemic loss of energy.
Following communication system will be based on data service, is not too strict to the requirement of time delay.Like this can adopt the multi-access mode of packet switching (Packet Switch).When adopting packet switching, the base station needs to give different users channel allocation in real time, is called user's scheduling (User Scheduling) here.There are two kinds of user scheduling methods the most basic to be applied in the wireless communication system at present.A kind of is circulation (Round Robin) scheduling, and promptly channel is distributed to all users by the mode of circulation.The effect of this method is the same with circuit switching, has guaranteed the fairness between delay character and user, but does not improve performance.Another kind of user's dispatching technique is channel-aware scheduling (Channel-aware Scheduling), and it can be according to user's channel fading situation h
k(in a single aerial system, it is a complex scalar) dynamically distributed to the right to use of current channel and had maximum Carrier interference ratio and (can simply think max|h
k|) the user.Like this, the performance of system can be greatly improved.The performance gain that obtains by the max carrier to interference scheduling is called multi-user diversity (Multiuser Diversity).
But because the channel-aware scheduling is the distribution that decides common signal channel according to channel situation, its dependence to channel conditions is bigger.Like this, under some special channel conditions, the performance of system just has significant decline.
Fig. 1 (a) and 1 (b) have provided the system construction drawing when base station (transmitting terminal) has a transmitting antenna and have two users (receiving terminal).In this system, the channel-aware scheduling is the distribution that decides common signal channel according to channel situation.
In Fig. 2, (a) be illustrated in the situation of channel conditions channel gain when good; (b) there are sight line path (Line of Sight, the situation of channel gain in the time of LoS) in the expression channel; (c) the expression system is in the situation of channel gain when decaying slowly.
In Fig. 2, curve 1 expression user's 1 time dependent channel gain curve, curve 2 expression users' 2 time dependent channel gain curve, dotted line is represented the time dependent average channel gain curve of current system.As can be seen, in the different moment, system decides the distribution of common signal channel according to user 1 and user's 2 channel gain, promptly at 0-t from (a)
1Period is distributed to user 1, t
1-t
2Period is distributed to user 2 or the like, represents with " 1 ", " 2 " on time shaft respectively.At last, the channel gain of system then is the coenvelope of curve 1 and curve 2, asks it on average to obtain the system's average channel gain curve shown in the dotted line.
Relatively (a) and (b) can learn that when having a sight line path in the channel, because this sight line path will reduce the fluctuation of channel coefficients, it causes the average channel gain reduction of attainable system.And from (b) and (c) (period that bracket is indicated) as can be seen, when system declines when slow, propagation delay time will be bigger.
For addressing this problem, people such as P.Viswanath, D.N.C.Tse and R.Laroia have proposed a kind of solution and (have consulted " Opportunistic beamforming using dumb Anntennas ", IEEETrans.Infor.Theory, Vol.48, No.6, pp.1277-1294.June.2002 calls " list of references 1 " in the following text).
In the method, suppose that the base station is equipped with n
TThe root antenna, and each user is a reception antenna, and user's channel is a vector
Before emission, data-signal is multiplied by a n
TDimension random complex vector
Then, with this data-signal from all n
TThe root antenna is launched.At this moment, each user detects channel gain and is actually an equivalent channel gain that combines real channel and emission vector
Each user feeds back to the base station to its detected equivalent channel gain, and then channel allocation is given the user with maximum equivalent channel gain in the base station.
For example, in Fig. 1 a and Fig. 1 b, the user with maximum equivalent gain just in time is positioned at by the vectorial h of emission
kIn the main lobe of the launching beam that forms.Like this,, just can change the statistical property (for example correlation properties, time-varying characteristics etc.) of equivalent channel gain, make it satisfy the requirement of user's scheduling by changing random complex vector W.
The performance of system also depends on the probability distributing density function f of random vector to a great extent
Pdf(w).Said method is in narrowband systems, provides under the flat fading channel situation.Yet present system is generally broadband system, and very strong frequency selective fading is arranged, and therefore directly adopts the impossible wave beam that forms on certain direction of said method.Simultaneously, according to multi-carrier modulation technology, signal bandwidth can be divided into a lot of subcarriers, and each subcarrier can experience a flat fading channel.Like this, can realize accidental beam shaping at each subcarrier.The user can compete each subcarrier by the equivalent channel gain of measuring on each subcarrier.
Fig. 3 has provided the schematic diagram of the signal processing of transmitting terminal in this case.Can see the data d on each subcarrier
iAll to be multiplied by a vectorial w who produces at random
n, n=1 ..., Nc forms the frequency-region signal that is input to different antennae.Frequency-region signal on the different antennae forms time-domain signal through IFFT again.This time-domain signal is launched by corresponding antenna after adding Cyclic Prefix.We can see from Fig. 3, to this system, need to produce Nc n altogether
TThe random vector of dimension, and need carry out n
TInferior IFFT.This will produce following problem:
1. the generation of random number is generally by some pseudorandom methods.And what need here all is some random sequences with time correlation characteristic.Producing so many random numbers needs a lot of corresponding pseudo-random generators, causes the increase of hardware resource or the raising of algorithm complex;
2. the performance of this system should depend on the joint probability density function f of all random vectors
Pdf(w
1..., w
Nc).In principle, this function is that certain optimization space is arranged, but goes autotelic optimization that very multivariable function is arranged, and very large difficulty is arranged on mathematics;
3. this scheme needs and the number of times of the as many IFFT of number of transmit antennas, and the complexity of algorithm is o (n
TNcLogNc), than higher.
Therefore, need provide a kind of communication system and communication means thereof that can overcome above-mentioned shortcoming.
Summary of the invention
The objective of the invention is to, a kind of multicarrier MIMO communication system is provided.
Another object of the present invention is to, a kind of communication means that is used for above-mentioned multicarrier MIMO communication system is provided.
According to a first aspect of the invention, multicarrier MIMO communication system of the present invention, it comprises the transmitting terminal that is used to send the Frame that has channel estimating signal and user data at least, and is used for Frame that receiving end/sending end sends, produces corresponding feedback signal and reduces at least one receiving terminal of user data.Wherein, this transmitting terminal comprises: duplexer group and position transmitting antenna thereon are used to send Frame, and receive the feedback signal from receiving terminal; The multicarrier MIMO scheduler is used for producing schedule information according to this feedback signal; The multicarrier MIMO data processor is used for selecting according to schedule information the user of needs scheduling, and selected user's data is formed corresponding multicarrier transmits.This receiving terminal comprises: duplexer group and position reception antenna thereon are used to receive the Frame from transmitting terminal, and send field feedback; Multicarrier received signal processor is used for producing user feedback data and reduction user data according to Frame; Feedback information processor is used for field feedback is changed into feedback signal.
According to second aspect present invention, the communication means of multicarrier MIMO communication system of the present invention, it may further comprise the steps:
(a), produce feedback signal according to the channel fade condition between the reception antenna of the transmitting antenna of transmitting terminal and receiving terminal, and this feedback signal is fed back to transmitting terminal at receiving terminal;
(b) at transmitting terminal, receive this feedback signal, produce schedule information according to this feedback signal;
(c) at transmitting terminal, according to schedule information the data of institute's dispatched users are formed corresponding multicarrier and transmit, the transmitting antenna by correspondence sends signal with this multicarrier and sends; And
(d) at receiving terminal, according to the launching beam reduction user data that receives.
Compared with prior art, multicarrier MIMO communication system of the present invention and channel capacity that communication means provided thereof are higher than the channel capacity that existing multicarrier MIMO communication means can provide.In addition, multicarrier MIMO communication system of the present invention is owing to adopted a kind of new multicarrier beam-shaper and random vector generator, it can overcome existing multicarrier MIMO communication system needs a lot of pseudo-random generators to produce the shortcoming of a large amount of random numbers, can optimize simultaneously the joint probability density function of random vector, and the complexity of algorithm is also lower.
Description of drawings
The present invention please refer to accompanying drawing described below for further explaining:
Fig. 1 (a) and (b) be system construction drawing when the base station has a transmitting antenna and has two users.
Fig. 2 (a) is for being illustrated in the situation of channel conditions channel gain when good; The situation of channel gain when (b) having sight line path in the expression channel; (c) the expression system is in the situation of channel gain when decaying slowly.
Fig. 3 is the schematic representation of apparatus that realizes the multicarrier accidental beam shaping in traditional mimo system.
Fig. 4 is the frame diagram that the present invention is based on random emitting beam formed multicarrier MIMO communication system.
Fig. 5 is the flow chart of user's scheduling of multicarrier MIMO communication system shown in Figure 4.
The schematic diagram of the frame structure that Fig. 6 is adopted for multicarrier MIMO communication system of the present invention.
Fig. 7 has further described the structural representation of the transmitting terminal 10 of MIMO communication system of the present invention.
Fig. 8 is the concrete structure figure of multicarrier beam-shaper 114 shown in Figure 7.
Fig. 9 is the structural representation of the transmission radio frequency link group of transmitting terminal 10.
Figure 10 is the schematic diagram of the duplexer group 130 of transmitting terminal 10 of the present invention.
Figure 11 has further described the structural representation of the receiving terminal 20 of MIMO communication system of the present invention.
Figure 12 to Figure 14 is the performance comparison diagram of different dispatching methods under the actual channel situation.
Embodiment
Below the present invention is just described in conjunction with the accompanying drawings.
Fig. 4 is the frame diagram of multicarrier MIMO communication system of the present invention, and wherein, this MIMO communication system comprises a transmitting terminal 10 (base station) and a plurality of receiving terminal 20 (user).Fig. 5 is the flow chart of user's scheduling of MIMO communication system shown in Figure 4.The schematic diagram of the frame structure that Fig. 6 is adopted for multicarrier MIMO communication system of the present invention.
Shown in Fig. 4-6, transmitting terminal 10 has multicarrier MIMO data processor 110, multicarrier MIMO scheduler 120, duplexer group 130 and n
TThe root transmitting antenna.Each receiving terminal 20 has multicarrier received signal processor 210, feedback information processor 220, duplexer group 230 and n
RThe root reception antenna.Wherein, the reception antenna quantity of each receiving terminal 20 can be different.This frame structure comprises: channel estimating time slot, channel feedback time slot and transfer of data time slot, and other time slot can be set according to system requirements, be to simplify for convenience of description here.
The schedule information acquisition process
As can be seen from Figure 6, transmitting terminal 10 at first can be by duplexer group 130 from n before sending user data signal
TThe root transmitting antenna is with the form of launching beam, to receiving terminal 20 transmitting channel estimated signal.
The transmission signal of supposing transmitting terminal 10 is a n
TThat ties up is complex vector located
That each receiving terminal 20 receives is a n
RThat ties up is complex vector located
There is a n between transmitting terminal 10 and the receiving terminal 20
R* n
TThe channel fading matrix of dimension:
Wherein,
Channel transfer characteristic (wherein k represents k user) between expression transmitting terminal 10 i root transmitting antennas and the receiving terminal 20 j root antennas.
Then, system transter can be expressed as:
y
k＝H
kx
k+μ
k
(2)
k＝1，...，K
Wherein
Be a n
RThat ties up is complex vector located, represents the white noise of receiving terminal 20.
Like this, for each receiving terminal 20, it knows definite channel fade condition, and in fact this channel fade condition combines the random complex vector of real channel decline situation and transmitting terminal.According to this channel fade condition, each receiving terminal 20 can be handled it by multicarrier received signal processor 210, thereby obtains field feedback, and sends it to feedback information processor 220.
After the antenna of transmitting terminal 10 receives this feedback signal, send it to multicarrier MIMO scheduler 120.Multicarrier MIMO scheduler 120 produces schedule information according to this signal, and utilizes the operation of the schedule information control multicarrier MIMO data processor 110 that is produced, thus the dispatch state when making the MIMO communication system reach maximum system capacity.That is, carry out optimized user's scheduling according to schedule information.
The method of above-mentioned acquisition channel fade condition is by utilizing channel estimating signal (being pilot signal) to carry out, it inserts the channel estimating signal in Frame, receiving terminal 20 is further handled the back field feedback that obtains by 210 pairs of channel fade condition of multicarrier received signal processor according to the channel fade condition between this channel estimating signal acquisition transmitting terminal 10 and the receiving terminal 20.
Yet, also can utilize the blind estimation mode of channel to obtain channel fade condition among the present invention.Promptly, do not need to be provided with the channel estimating time slot in the Frame, receiving terminal 20 obtains channel fade condition receiving the data while that transmitting terminal 10 sends by the blind estimation of channel, handles the back field feedback that obtains by 210 pairs of channel fade condition of multicarrier received signal processor then.Can avoid the waste of the frequency spectrum resource that insertion caused of channel estimating signal this moment.
Fig. 7 has further described the structural representation of the transmitting terminal 10 of MIMO communication system of the present invention.Fig. 8 is a kind of concrete structure figure of multicarrier beam-shaper 114 shown in Figure 7.Fig. 9 is the structural representation of the transmission radio frequency link group of transmitting terminal 10, and Figure 10 is the schematic diagram of the duplexer group 130 of transmitting terminal 10 of the present invention.Figure 11 has further described the structural representation of the receiving terminal 20 of MIMO communication system of the present invention.In Fig. 7 and Figure 11, adopt layering space-time signal processing mode to carry out the description that MIMO communicates by letter.For signal processing, signal processing method and the device that can take other prior aries to disclose are equally carried out, for example the Space Time Coding mode.
User data transmission/reception and scheduling process
Transmitting terminal 10
In Fig. 7, this transmitting terminal 10 comprises multicarrier MIMO data processor 110, multicarrier MIMO scheduler 120, duplexer group 130 and n
TThe root transmitting antenna.
This multicarrier MIMO scheduler 120 comprises received RF link group 123, MIMO received signal processor 122 and scheduler 121.Wherein, received RF link group 123 has the received RF link with the transmitting antenna respective amount, and the feedback signal that is used for receiving is converted into corresponding code stream.The signal processing when code stream that MIMO received signal processor 122 will transform carries out sky, obtain corresponding scheduling information, this schedule information comprises: the appointment launching beam on the code stream that user, each user supported that dispatch, the designate sub that sends each code stream.Scheduler 121 utilizes the signal processing of this schedule information control multicarrier MIMO data processor 110.
This multicarrier MIMO data processor 110 comprises subscriber selector 111, the shunt 112 of a plurality of parallel arranged, carrier beams distributor 113, the multicarrier beam-shaper 114 of a plurality of parallel arranged, adder group 118, Cyclic Prefix device group 115 send radio frequency link group 116 and random vector generator 117.
Wherein, under the control of schedule information (according to " user that will dispatch " in the schedule information), subscriber selector 111 is used to select the user that will dispatch, and quantitaes here is nS, and exports corresponding user data.
Under the control of schedule information, nS shunt 112 is selected shunts processing to nS the user data of users of being dispatched, that is,, nS the user data of users of being dispatched is divided into L code stream output according to " code stream that each user supported " in the schedule information.L is the summation of the code stream number assigned to of the data of all dispatched users.
Then, by carrier beams distributor 113 L code stream of shunt 112 output being considered as L different layers handles, according to " sending the appointment launching beam on the designate sub of each code stream " in the schedule information, L the code stream that sends is assigned to respectively on the appointment launching beam of designate sub, just, L code stream is assigned to frequency domain and spatial domain channel, forms a plurality of frequency-region signals.Here, suppose that the sub-carrier number in this multicarrier MIMO communication system is N
c, number of transmit antennas is n
T, then, be output as N this moment
c* n
TIndividual frequency-region signal promptly, is supported n on each subcarrier
TIndividual launching beam.At N
c* n
TIn the individual frequency-region signal, have only L frequency-region signal just to have user data.
Next, this N
c* n
TIndividual frequency-region signal is input to n respectively
TIn the individual multicarrier beam-shaper 114, its principle is, for the n on the same subcarrier
TIndividual frequency-region signal is input to n respectively
TIn the individual multicarrier beam-shaper 114 in the corresponding multicarrier beam-shaper 114, just, with N
c* n
TThe N that belongs to same spatial domain channel in the individual frequency-region signal
cIndividual frequency-region signal is input in the corresponding multicarrier beam-shaper 114.Therefore, each multicarrier beam-shaper 114 receives N respectively
cIndividual frequency-region signal corresponding to this subcarrier beam-shaper, each frequency-region signal is corresponding to a subcarrier.
Random vector generator 117 produces random vector, and the random vector that produces is input to respectively in the corresponding multicarrier beam-shaper 114.
The random vector that each multicarrier beam-shaper 114 is produced according to random vector generator 117 is with input N wherein
cIndividual frequency-region signal carries out beam shaping to be handled, and forms respectively at n
TThe n of root antenna
TIndividual time domain sends signal, that is, each time domain sends signal corresponding to n
TA transmitting antenna in the root transmitting antenna.Its essence is that each time domain sends signal corresponding to all N
cOne of individual subcarrier spatial domain channel independently.All n
TIndividual multicarrier beam-shaper 114 will form n
T* n
TIndividual transmission signal.
By having n
TCorresponding in the adder group 118 of an individual adder adder will be corresponding to the n of same transmitting antenna
TIndividual time domain sends signal and superposes, and forms total transmitting, like this, from different multicarrier beam-shapers, corresponding to the time domain transmission signal of same transmitting antenna corresponding to a spatial domain-frequency domain channel independently.Then, each adder outputs to transmitting of its formation in the Cyclic Prefix device group 115.n
TIndividual adder is exported n altogether
TIndividually correspond respectively to transmitting of a transmitting antenna.
Cyclic Prefix device group 115 comprises n
TIndividual Cyclic Prefix device, each Cyclic Prefix device is corresponding to a transmitting antenna.Each Cyclic Prefix device to from multicarrier beam-shaper 114, corresponding to the insertion Cyclic Prefix that transmits of same transmitting antenna, the transmitting of Cyclic Prefix that generated corresponding insertion.n
TIndividual Cyclic Prefix device is exported n altogether
TThe individual n that corresponds respectively to
TTransmitting of root transmitting antenna.
Send radio frequency link group 116, be used to receive n from 115 outputs of Cyclic Prefix device group
TIndividual transmitting is with this n
TIndividual transmitting is converted into corresponding radiofrequency signal, and with each pairing radiofrequency signal that transmits all by the n on the duplexer group 130
TThe root transmitting antenna sends.
Particularly, specify multicarrier beam shaping process in the multicarrier MIMO communication system below with reference to Fig. 8.
As shown in Figure 8, each multicarrier beam-shaper 114 comprises an IFFT converter 1141, n
TThe serial combination that route multiplier 1142 and delayer 1143 are formed.
The N of the correspondence of these IFFT converter 1141 reception carrier beam allocation devices 113 outputs
cIndividual frequency-region signal forms the serial time-domain signal by the IFFT conversion, and this serial time-domain signal is outputed to the n that is made up of multiplier 1142 and 1143 concurrently respectively
TIn the serial combination of road.Wherein, N
cThe pairing subcarrier of individual frequency-region signal differs from one another.
Simultaneously, random vector generator 117 is input to n with the random vector that produces
TIn the multicarrier beam-shaper 114 of the correspondence in the individual multicarrier beam-shaper 114.This random vector comprises vector
And vector
Wherein,
With
Represent the weight and the time-delay of the j road serial time-domain signal that i the IFFT converter 1141 in the multicarrier beam-shaper 114 exported respectively, 0≤i≤n
T, 0≤j≤n
T
The serial combination that every route multiplier 1142 and delayer 1143 are formed is according to the vector of random vector generator 117 inputs
Input serial time-domain signal wherein is weighted processing, and according to
This serial time-domain signal is carried out delay process, form one and send signal.This weighted and delay process are equivalent to:
Like this, each multicarrier beam-shaper 114 will form n
TIndividual transmission signal, n
TIndividual multicarrier beam-shaper 114 will form n
T* n
TIndividual transmission signal.Wherein, the n that forms at each multicarrier beam-shaper 114
TIndividual transmission signal corresponds respectively to n
TA transmitting antenna in the root transmitting antenna.
For n
TThe n of individual multicarrier beam-shaper 114 outputs
T* n
TIn the individual transmission signal corresponding to the transmission signal of same transmitting antenna, be input to Cyclic Prefix device corresponding in the Cyclic Prefix device group 115 after forming corresponding transmitting by adder stack corresponding in the adder group 118, to wherein the insertion Cyclic Prefix that transmits of input, and the signal that will insert Cyclic Prefix sends to transmission radio frequency link group 116 by this corresponding Cyclic Prefix device.N in the Cyclic Prefix device group 115
TIndividual Cyclic Prefix device is exported n altogether
TTransmitting of individual insertion Cyclic Prefix.
Further described the concrete structure that sends radio frequency link group 116 among Fig. 9, it comprises n
TIndividual parallel transmission radio frequency link, each sends radio frequency link and has modulator connected in series 1161, upconverter 1162 and power amplifier 1163, and this power amplifier can be high-power linear amplifier.Wherein, this n
TSend radio frequency link and be respectively applied for the n that Cyclic Prefix device group 115 is exported
TIndividual transmitting is converted into corresponding radiofrequency signal.
Figure 10 is the schematic diagram of the duplexer group 130 of transmitting terminal 10 of the present invention.Wherein, this duplexer group 130 comprises n
TIndividual parallel duplexer.Each duplexer is connected with a corresponding transmitting antenna, and all is connected to transmission radio frequency link group 116 and received RF link group 123.
Receiving terminal 20
In order to simplify description, only show one of them receiving terminal 20 here.
In Figure 11, this receiving terminal 20 has multicarrier received signal processor 210, feedback information processor 220, duplexer group 230 and n
RThe root antenna.
Wherein, this multicarrier received signal processor 210 comprises received RF link group 211 and MIMO received signal processor 212.This feedback information processor 220 comprises that MIMO sends signal processor 221 and sends radio frequency link group 222.
This received RF link group 211 has and reception antenna quantity n
RIdentical parallel received RF link (figure does not show), the radiofrequency signal that is used for receiving reverts to corresponding code stream, and sends to MIMO received signal processor 212.
This MIMO received signal processor 212 is reduced to original user data with code stream, and with its output.
Below scheduling process of the present invention will be described according to different user scheduling methods.For receiving terminal 20, in scheduling of the present invention, have the receiving terminal 20 of many antennas for each, it can be considered to the receiving terminal with an antenna 20 of equal number.Therefore, the situation that we only have an antenna with each receiving terminal 20 here describes, and this explanation can be extended to each receiving terminal 20 and have the situation of many antennas.
First dispatching method
For each receiving terminal 20, it can be handled by multicarrier received signal processor 210 to received signal according to this channel fade condition, obtains field feedback, and sends it to feedback information processor 220.Wherein, comprise in this field feedback: on each subcarrier, the combination n of best launching beam for this receiving terminal
k, the pairing signal interference ratio GNI of each launching beam in this best launching beam combination
k
Wherein, w
nThe random complex vector of expression transmitting terminal (is equivalent in the formula (3)
), H
kChannel fading matrix between expression transmitting terminal 10 and the receiving terminal 20.
When the scheduler 121 of transmitting terminal 10 receives feedback signal, carry out system call.Because each receiving terminal 20 has all fed back the combination n of its launching beam best on each subcarrier
k, the pairing signal interference ratio GNI of each launching beam in this best launching beam combination
k, therefore, scheduling process mainly comprises:
1) user's dispatch list SU and distributed launching beam tabulation SB for empty is set;
2), will repeat following steps i for each subcarrier) extremely iii):
I) all signal interference ratio GNI that feed back relatively
k, selecting one has maximum signal interference ratio GNI
kThe user join among user's dispatch list SU, and a corresponding launching beam be added to distribute among the launching beam tabulation SB;
Ii) then, all signal interference ratio GNI that feed back relatively
k, never select signal interference ratio GNI among Tiao Du the user with maximum
kThe user, it is joined among user's dispatch list SU, and a corresponding launching beam is added to distributes among the launching beam tabulation SB;
Iii) repeating step i) and ii), until user's scheduling of finishing on this carrier wave;
3) last, according at last at user's dispatch list SU that all subcarriers generated with distributed the launching beam SB that tabulates, control multicarrier MIMO data processor 110 is divided into independently code stream to the data flow of institute's dispatched users and is assigned on the appointment launching beam of designate sub, thereby sends from transmitting antenna.
In above-mentioned scheduling step 2) in, for each subcarrier, if joined among user's dispatch list SU at certain receiving terminal 20 (user), and, when choosing in its best launching beam group another launching beam, because this receiving terminal 20 has only an antenna, so it can not be dispatched again.At this moment, for user's finishing scheduling that this subcarrier carried out.
Simultaneously, in above-mentioned scheduling step 2) in, for each subcarrier,, distributed in the launching beam tabulation launching beam of this user's correspondence if having joined, and then this user can not be scheduled.At this moment, for user's finishing scheduling that this subcarrier carried out.
Have the situation of many antennas for each receiving terminal 20, if every antenna is assumed to be a receiving terminal (user), the scheduling situation of many antennas of each receiving terminal has only the scheduling situation of an antenna similar with each receiving terminal so.
Second dispatching method
When multicarrier MIMO communication system of the present invention is considered the interference between the launching beam on each subcarrier and the number of users that will dispatch is fixing M (1＜M * N
c＜n
T) time, for each receiving terminal 20, it can be handled by multicarrier received signal processor 210 to received signal according to channel fade condition, obtains field feedback, and sends it to feedback information processor 220.Wherein, comprise in this field feedback: on each subcarrier, for the combination n of the best launching beam of this receiving terminal 20
k, this best launching beam combination n
kIn the corresponding signal interference ratio GNI of each launching beam
k, and this receiving terminal disturb the combination Q of minimum launching beam
kWherein, on each subcarrier, for best launching beam combination n
kIn preferably launching beam quantity and receiving terminal disturbed minimum (M-1) individual launching beam combination Q
kThe quantity of middle launching beam can be selected according to the actual channel situation, and its principle is that same launching beam can not be included in these two combinations simultaneously.
Wherein, S is illustrated in the n on each subcarrier
TSelect (M-1) individual different minimum all possible set of wave beam of disturbing in the individual wave beam.
When the scheduler 121 of transmitting terminal 10 receives feedback signal, carry out system call.At this moment, because each receiving terminal 20 has all fed back the combination n of its best launching beam on each subcarrier
k, this best launching beam combination n
kIn the pairing signal interference ratio GNI of each launching beam
k, and the combination Q that this receiving terminal disturbed minimum (M-1) individual launching beam
k, therefore, scheduling process mainly comprises:
1) user's dispatch list SU and distributed launching beam tabulation SB for empty is set;
2), will repeat following steps i for each subcarrier) extremely iii):
I) all signal interference ratio GNI that feed back relatively
k, selecting one has maximum signal interference ratio GNI
kThe user join among user's dispatch list SU, and a corresponding launching beam be added to distribute among the launching beam tabulation SB;
Ii) at the user in user's dispatch list, from the combination Q of its correspondence
kIn find out the corresponding minimum launching beam that disturbs, then, find out the user of its pairing maximum signal interference ratio, and this user is joined in user's dispatch list according to the minimum launching beam of this interference, simultaneously, the launching beam of this user's correspondence is added to distributes in the launching beam tabulation;
Iii) repeating step i) and ii), up to user's scheduling of finishing on this subcarrier;
3) last, according to the user's dispatch list SU that generates at all subcarriers at last with distributed the launching beam SB that tabulates, control multicarrier MIMO data processor 110 is divided into independently code stream to the data flow of institute's dispatched users and is assigned on the appointment launching beam of designate sub, thereby sends from transmitting antenna.
The 3rd dispatching method
When multicarrier MIMO communication system of the present invention is considered interference between the launching beam on each subcarrier and this interference to the influencing of power system capacity, for each receiving terminal 20, it is according to this channel fade condition, can handle to received signal by multicarrier received signal processor 210, obtain field feedback, and send it to feedback information processor 220.Wherein, comprise in this field feedback: on each subcarrier, for the combination n of these receiving terminal 20 best launching beams
k, this best launching beam combination n
kIn the pairing equivalent channel gain GN of each launching beam
k, this receiving terminal disturbed the combination Q of minimum launching beam
k, and should the combination Q
kIn each launching beam D is compared in the performance loss of the best launching beam of this receiving terminal
K, i
{D
k，i}＝{GN
k/|h
k *w
i|
2，i∈Q
k} (7)
When the scheduler 121 of transmitting terminal 10 receives feedback signal, carry out system call.At this moment, because each receiving terminal 20 has all fed back the combination n of its best launching beam on each subcarrier
k, this makes up n
kIn the equivalent channel gain GN of each launching beam
k, this receiving terminal disturbed the combination Q of minimum launching beam
k, and should the combination Q
kIn each launching beam D is compared in the performance loss of the best launching beam of this receiving terminal
K, i, therefore, scheduling process mainly comprises:
1) user's dispatch list SU and distributed launching beam tabulation SB for empty is set;
2), will repeat following steps i for each subcarrier) extremely iv):
I) all equivalent channel gain GN that feed back relatively
k, selecting one has maximum equivalent channel gain GN
kThe user join among user's dispatch list SU, and a corresponding launching beam be added to distribute among the launching beam tabulation SB;
Ii) at the user in user's dispatch list, from the combination Q of its correspondence
kIn find out the corresponding minimum launching beam that disturbs, should disturb the user of the minimum pairing maximum signal interference ratio of launching beam then;
Iii) compare D according to the performance loss of feedback
K, i, judge whether this user's adding has increased power system capacity, if this user's adding makes power system capacity increase, then this user is joined in user's dispatch list, simultaneously, the launching beam of this user's correspondence is added to distributes in the launching beam tabulation.If this user's adding makes power system capacity reduce, then this user is not joined user's dispatch list, and finish the user's scheduling on this subcarrier;
Iv) after this user adds, repeating step i successively) and iii), up to the user's finishing scheduling on this subcarrier;
3) last, according at last at user's dispatch list SU of all subcarriers with distributed the launching beam SB that tabulates, control multicarrier MIMO data processor 110 is divided into independently code stream to user's data stream, on the appointment launching beam of the designate sub that is assigned to, send from transmitting antenna then.
Therefore, the 3rd dispatching method is dispatched users adaptively, thereby can utilize channel conditions fully, and maximum channel capacity is provided.
In order more clearly to embody the superiority of dispatching patcher of the present invention and dispatching method, see also Figure 12 to Figure 14, the performance that has provided different dispatching methods in the actual channel here compares, wherein sub-carrier number N
c=64, code stream is counted L=3, transmitting power P=10.
In Figure 12, abscissa is represented Ricean factor k, and ordinate is represented the channel capacity that obtained.When the antenna number of transmitting terminal be 2, when number of users is 32, increase along with Ricean factor k, channel capacity reduces gradually, compare the method for announcement in the list of references 1 and traditional random Gaussian method of weighting, adopt communication means of the present invention, the reduction of channel capacity is little and relatively mild.
In Figure 13, abscissa is represented number of users, and ordinate is represented the channel capacity that obtained.When the antenna number of Ricean factor k=10, transmitting terminal is 2, along with the increase of number of users, compare the method for announcement in the list of references 1 and traditional random Gaussian method of weighting, adopt communication means of the present invention, can obtain bigger channel capacity increment.
In Figure 14, abscissa is represented the number of transmit antennas of transmitting terminal, and ordinate is represented the channel capacity that obtained.At number of users is 256 o'clock, along with the increase of number of transmit antennas, compares the method for announcement in the list of references 1 and traditional random Gaussian method of weighting, adopts communication means of the present invention can obtain bigger channel capacity increment.
By as can be seen above-mentioned, the channel capacity that communication system of the present invention and communication means are provided is higher than the method for announcement in the list of references 1 and the channel capacity that traditional random Gaussian method of weighting can provide.
In sum, multicarrier MIMO communication system of the present invention can be carried out user's scheduling according to channel conditions at that time, different feedback informations with communication means, the intellectuality and the communication stability of the control of raising system, and remain maximum power system capacity.Except can obtaining maximum channel capacity, multicarrier MIMO communication system of the present invention is owing to adopted a kind of new algorithm, it can overcome existing multicarrier MIMO communication system needs a lot of pseudo-random generators to produce the shortcoming of a large amount of random numbers, can optimize simultaneously the joint probability density function of random vector, and the complexity of algorithm is also lower.
Claims (16)
1. multicarrier MIMO communication system, it comprises the transmitting terminal (10) that is used to send the Frame that has channel estimating signal and user data at least, and be used for Frame that receiving end/sending end (10) sends, produce corresponding feedback signal and reduce at least one receiving terminal (20) of user data, it is characterized in that:
This transmitting terminal (10) comprising:
The first duplexer group (130) and position transmitting antenna thereon are used to send Frame, and receive the feedback signal from receiving terminal (20);
Multicarrier MIMO scheduler (120) is used for producing schedule information according to this feedback signal;
Multicarrier MIMO data processor (110) is used for selecting according to schedule information the user of needs scheduling, and selected user's data is formed corresponding multicarrier transmits, and
This receiving terminal (20) comprising:
The second duplexer group (230) and position reception antenna thereon are used for receiving the Frame from transmitting terminal (10), and send feedback signal;
Multicarrier received signal processor (210) is used for producing user feedback data and reduction user data according to Frame;
Feedback information processor (220) is used for user feedback data is changed into feedback signal;
Wherein, this multicarrier MIMO data processor (110) comprising:
Subscriber selector (111) is used for according to schedule information, selects the user that will dispatch;
The shunt of a plurality of parallel arranged (112) is used for the user data of users of being dispatched is shunted processing, exports a plurality of code streams;
Carrier beams distributor (113) is used for according to schedule information, and the code stream that shunt is exported is assigned to respectively on the corresponding wave beam of the specified corresponding subcarrier of schedule information, forms a plurality of frequency-region signals;
Random vector generator (117) is used for producing and the output random vector, and described random vector is weight vectors and time-delay vector;
A plurality of parallel multicarrier beam-shapers (114), each multicarrier beam-shaper is according to the frequency-region signal that is received from carrier beams distributor (113) and from the random vector of random vector generator (117), form a plurality of respectively with a time-domain signal that transmitting antenna is corresponding;
Adder group (118) has a plurality of adders, and each adder will superpose corresponding to the time-domain signal of same transmitting antenna respectively, forms one and transmits;
Cyclic Prefix device group (115) has a plurality of Cyclic Prefix devices, and each Cyclic Prefix device is insertion Cyclic Prefix in the transmitting of the adder of correspondence output respectively; And
First sends radio frequency link group (116), is used to receive a plurality of the transmitting of Cyclic Prefix device group (115) output, and this a plurality of transmitting is separately converted to corresponding radiofrequency signal;
Wherein, each multicarrier beam-shaper (114) comprises an IFFT converter (1141), and the serial combination of multirouting multiplier (1142) and delayer (1143) composition, wherein,
IFFT converter (1141) frequency-region signal of self-contained wave-wave bundle distributor (113) in the future carries out the IFFT conversion, forms the serial time-domain signal, and this serial time-domain signal is input in the above-mentioned multi-path serial combination simultaneously;
In the serial combination of every route multiplier (1142) and delayer (1143) composition, multiplier (1142) and delayer (1143) are weighted processing and delay process according to weight vectors and the time-delay vector that random vector generator (117) is exported to this serial time-domain signal respectively successively, generate the time-domain signal corresponding to a transmitting antenna.
2. multicarrier MIMO communication system as claimed in claim 1 is characterized in that, this feedback signal is included on each subcarrier, the signal interference ratio of each launching beam correspondence in the launching beam group that each receiving terminal (20) is best and this best launching beam group.
3. multicarrier MIMO communication system as claimed in claim 2 is characterized in that, this feedback signal further is included on each subcarrier, each receiving terminal (20) is disturbed the combination of minimum launching beam.
4. multicarrier MIMO communication system as claimed in claim 1, it is characterized in that, this feedback signal is included on each subcarrier, the equivalent channel gain of each launching beam in the combination of the best launching beam of each receiving terminal, this combination, to this receiving terminal disturb minimum launching beam combination and should combination in each launching beam to the performance loss ratio of the best launching beam of this receiving terminal.
5. as each described multicarrier MIMO communication system of claim 1 to 4, it is characterized in that this schedule information comprises the appointment launching beam on the code stream that user, each user supported that will dispatch and the designate sub that sends each code stream.
6. multicarrier MIMO communication system as claimed in claim 5 is characterized in that,
This multicarrier MIMO scheduler (120) comprising:
The first received RF link group (123), the feedback signal that is used for receiving is converted into corresponding code stream;
The one MIMO received signal processor (122), the signal processing when code stream that is used for transforming carries out sky obtains corresponding scheduling information; And
Scheduler (121) is used for the signal processing according to this schedule information control multicarrier MIMO data processor (110).
7. multicarrier MIMO communication system as claimed in claim 6, it is characterized in that, this first transmission radio frequency link group (116) comprises a plurality of parallel transmission radio frequency links, a plurality of transmitting with Cyclic Prefix device group (115) output is converted into corresponding radiofrequency signal respectively, and each sends radio frequency link and comprises a modulator (1161) connected in series, a upconverter (1162) and a power amplifier (1163).
8. multicarrier MIMO communication system as claimed in claim 7 is characterized in that,
This multicarrier received signal processor (210) comprising:
One second received RF link group (211) is used for the radiofrequency signal that receives is separated the mediation frequency-conversion processing, obtains corresponding code stream;
One the 2nd MIMO received signal processor (212) is used for producing corresponding user feedback data according to this code stream, reduces and export user data simultaneously; And
This feedback information processor (220) comprising:
One MIMO sends signal processor (221), is used for user feedback data is changed into feedback signal;
One second sends radio frequency link group (222), is used for this feedback signal is converted into corresponding radiofrequency signal.
9. multicarrier MIMO communication means, it may further comprise the steps:
(a), produce feedback signal according to the channel fade condition between the reception antenna of the transmitting antenna of transmitting terminal and receiving terminal, and this feedback signal is fed back to transmitting terminal at receiving terminal;
(b) at transmitting terminal, receive this feedback signal, produce schedule information according to this feedback signal;
(c) at transmitting terminal, according to schedule information the data of institute's dispatched users are formed corresponding multicarrier and transmit, the transmitting antenna by correspondence sends signal with this multicarrier and sends; And
(d) at receiving terminal, according to the launching beam reduction user data that receives;
Wherein, step (c) may further comprise the steps:
I) user that selection will be dispatched according to schedule information;
Ii) the user data of institute's dispatched users is divided into corresponding code stream according to schedule information;
Iii) each code stream is assigned on the appointment launching beam of designate sub according to schedule information, what will be assigned to same spatial domain channel respectively carries out the IFFT conversion at the code stream on all subcarriers, the output parallel multi-path serial time-domain signal corresponding respectively with transmitting antenna in each spatial domain channel;
Iv) every road serial time-domain signal is weighted successively the transmission signal of handling and postponing to handle the formation correspondence, and will superpose corresponding to the transmission signal of same transmitting antenna, the multicarrier that the back that superposes the is formed insertion Cyclic Prefix that transmits is launched from the transmitting antenna of correspondence then.
10. communication means as claimed in claim 9, wherein, this schedule information comprises the appointment launching beam on the code stream that user, each user supported that will dispatch and the designate sub that sends each code stream.
11. communication means as claimed in claim 10, wherein, this feedback signal is included on each subcarrier, the pairing signal interference ratio of each launching beam in the combination of best launching beam for this receiving terminal, this best launching beam combination.
12. communication means as claimed in claim 11, wherein, this feedback signal further comprises the combination of on each subcarrier each receiving terminal being disturbed minimum a plurality of launching beams.
13. communication means as claimed in claim 10, wherein, this feedback signal is included on each subcarrier, for this receiving terminal preferably the pairing equivalent channel gain of each launching beam in the combination of the combination of launching beam, this best launching beam, to this receiving terminal disturb minimum launching beam combination and should combination in each launching beam to the performance loss ratio of the best launching beam of this receiving terminal.
14. communication means as claimed in claim 11, wherein step (b) may further comprise the steps:
1) user's dispatch list and distributed launching beam tabulation for empty is set;
2), carry out following steps i for each subcarrier) extremely iii):
I) all signal interference ratios that feed back relatively, selecting one has the user of maximum signal interference ratio to join in user's dispatch list, and a corresponding launching beam is added to distributes in the launching beam tabulation;
Ii) then, all signal interference ratios that feed back are relatively never selected the user with maximum signal interference ratio among Tiao Du the user, it is joined in user's dispatch list, and a corresponding launching beam is added to distributes in the launching beam tabulation;
Iii) repeating step i) and ii), until user's scheduling of finishing on this carrier wave;
3) last, at user's dispatch list that all subcarriers generated with distributed the launching beam tabulation, the user who carries out system dispatches according at last.
15. communication means as claimed in claim 12, wherein step (b) may further comprise the steps:
1) user's dispatch list and distributed launching beam tabulation for empty is set;
2), carry out following steps i for each subcarrier) extremely iii):
I) all signal interference ratios that feed back relatively, selecting one has the user of maximum signal interference ratio to join in user's dispatch list, and a corresponding launching beam is added to distributes in the launching beam tabulation;
Ii) at the user in user's dispatch list, from the combination of its correspondence, find out the corresponding minimum launching beam that disturbs, then, find out the user of its pairing maximum signal interference ratio according to the minimum launching beam of this interference, and this user joined in user's dispatch list, simultaneously, the launching beam of this user's correspondence is added to distributes in the launching beam tabulation;
Iii) repeating step i) and ii), up to user's scheduling of finishing on this subcarrier;
3) last, according to the user's dispatch list that generates at all subcarriers at last with distributed the launching beam tabulation, the user who carries out system dispatches.
16. user scheduling method as claimed in claim 13, wherein step (b) may further comprise the steps:
1) user's dispatch list and distributed launching beam tabulation for empty is set;
2), will repeat following steps i for each subcarrier) extremely iv):
I) all equivalent channel gain that feed back relatively, selecting one has the user of maximum equivalent channel gain to join in user's dispatch list, and a corresponding launching beam is added to distributes in the launching beam tabulation;
Ii), from the combination of its correspondence, find out the corresponding minimum launching beam that disturbs, should disturb the user of the minimum pairing maximum signal interference ratio of launching beam then at the user in user's dispatch list;
Iii) according to the performance loss ratio that feeds back, whether the adding of judging this user has increased power system capacity, if this user's adding makes power system capacity increase, then this user is joined in user's dispatch list, simultaneously, the launching beam of this user's correspondence is added to distributes in the launching beam tabulation; If this user's adding makes power system capacity reduce, then this user is not joined user's dispatch list, and finish the user's scheduling on this subcarrier;
Iv) after this user adds, repeating step i successively) and iii), up to the user's finishing scheduling on this subcarrier;
3) according at last at user's dispatch list of all subcarriers with distributed the launching beam tabulation, the user who carries out system dispatches.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2005101156249A CN1964217B (en) | 2005-11-08 | 2005-11-08 | A multicarrier MIMO system and its communication method |
| JP2006301897A JP4839182B2 (en) | 2005-11-08 | 2006-11-07 | Multi-carrier MIMO system and communication method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2005101156249A CN1964217B (en) | 2005-11-08 | 2005-11-08 | A multicarrier MIMO system and its communication method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1964217A CN1964217A (en) | 2007-05-16 |
| CN1964217B true CN1964217B (en) | 2011-11-23 |
Family
ID=38083141
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2005101156249A Expired - Fee Related CN1964217B (en) | 2005-11-08 | 2005-11-08 | A multicarrier MIMO system and its communication method |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP4839182B2 (en) |
| CN (1) | CN1964217B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101090286A (en) * | 2006-06-12 | 2007-12-19 | 清华大学 | Radio system, base station device and terminal device |
| CN101529739A (en) | 2006-10-24 | 2009-09-09 | 三菱电机株式会社 | Transmitter apparatus, receiver apparatus, communication apparatus and communication system |
| CN101340605B (en) * | 2007-07-06 | 2012-04-04 | 中兴通讯股份有限公司 | Scheduling information uploading method for multi-carrier reinforced uplink access system |
| CN101373998B (en) * | 2007-08-20 | 2012-07-25 | 上海贝尔阿尔卡特股份有限公司 | Low information interactive multi-base station collaboration MIMO as well as scheduling method and apparatus thereof |
| JP5262332B2 (en) * | 2008-06-17 | 2013-08-14 | 住友電気工業株式会社 | Wireless communication system, base station apparatus, and wireless terminal apparatus |
| WO2016169598A1 (en) * | 2015-04-23 | 2016-10-27 | Telefonaktiebolaget Lm Ericsson (Publ) | Adaptive beamforming |
| CN111190165B (en) * | 2020-01-08 | 2024-01-30 | 中国船舶集团有限公司第七二四研究所 | Method for realizing serial beam synthesis |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1599276A (en) * | 2004-07-13 | 2005-03-23 | 中国科学技术大学 | Multi-antenna transmitting and receiving system and method using random beam forming |
| WO2005036775A2 (en) * | 2003-10-08 | 2005-04-21 | Atheros Communications, Inc. | Apparatus and method of multiple antenna transmitter beamforming of high data rate wideband packetized wireless communication signals |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3253281B2 (en) * | 1998-10-21 | 2002-02-04 | 松下電器産業株式会社 | Ultrasound diagnostic equipment |
| US7020110B2 (en) * | 2002-01-08 | 2006-03-28 | Qualcomm Incorporated | Resource allocation for MIMO-OFDM communication systems |
| JP2004064108A (en) * | 2002-07-24 | 2004-02-26 | Natl Univ Of Singapore | Wireless communication apparatus and method |
| JP4740123B2 (en) * | 2003-04-23 | 2011-08-03 | クゥアルコム・インコーポレイテッド | Method and apparatus for enhancing performance in a wireless communication system |
| JP4357884B2 (en) * | 2003-06-17 | 2009-11-04 | 三星電子株式会社 | Transmission diversity system, transmission diversity method and program thereof |
| CN1870461B (en) * | 2005-05-24 | 2011-06-01 | 都科摩（北京）通信技术研究中心有限公司 | MIMO system based on random emitting beam formed and its user scheduling method |
-
2005
- 2005-11-08 CN CN2005101156249A patent/CN1964217B/en not_active Expired - Fee Related
-
2006
- 2006-11-07 JP JP2006301897A patent/JP4839182B2/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005036775A2 (en) * | 2003-10-08 | 2005-04-21 | Atheros Communications, Inc. | Apparatus and method of multiple antenna transmitter beamforming of high data rate wideband packetized wireless communication signals |
| CN1599276A (en) * | 2004-07-13 | 2005-03-23 | 中国科学技术大学 | Multi-antenna transmitting and receiving system and method using random beam forming |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1964217A (en) | 2007-05-16 |
| JP2007135211A (en) | 2007-05-31 |
| JP4839182B2 (en) | 2011-12-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1870461B (en) | MIMO system based on random emitting beam formed and its user scheduling method | |
| CN1797987B (en) | Communication system for self-adaptive scheduling MIMO, and method for self-adaptive scheduling users | |
| CN103733540B (en) | Apparatus and method for supporting multi-antenna transmission in the wireless communication system of beam forming | |
| CN101034924B (en) | Radio communication method and radio base station | |
| US7889758B2 (en) | Method for allocating subchannel in wireless network | |
| KR102202935B1 (en) | A method and apparatus for energy efficient signal transmission in massive multi-antenna wireless communication systems | |
| CN101860951B (en) | Apparatus and method for controlling power in distributed multiple input multiple output wireless communication system | |
| CN1964217B (en) | A multicarrier MIMO system and its communication method | |
| CA2419263C (en) | Transmission control apparatus and transmission control method | |
| CN101557611B (en) | Downlink multiuser selection method used for multi-aerial system | |
| Han et al. | Greener physical layer technologies for 6G mobile communications | |
| JP2007020188A (en) | Mimo communication system and user scheduling method | |
| CN102983949B (en) | SDMA transmission method in multicarrier MU mimo system and base station | |
| CN101015137A (en) | Apparatus and method for beamforming in a multi-antenna system | |
| CN102412881A (en) | Wireless communication system and beamforming training method applied to wireless communication system | |
| CN101675601B (en) | A kind of method for communicating in mimo context | |
| CN101702700A (en) | Method for allocating minimum power of MIMO-OFDM multi-user system based on allelism | |
| KR101448639B1 (en) | A method for transmitting a data by collaborating of a plurality of base station in a multi-cell environments and a method for receiving using the same | |
| CN101472298B (en) | User scheduling method and apparatus for TDD multi-input multi-output down emission system | |
| CN101174870B (en) | Accidental beam shaping and transmitting method based on beam collection selection | |
| CN111917444B (en) | Resource allocation method suitable for millimeter wave MIMO-NOMA system | |
| CN101989894B (en) | Cooperative communication method, equipment and system | |
| Yadav et al. | Design of a scheduling algorithm in 3D MIMO beamforming 5G systems for interference mitigation | |
| CN102104406B (en) | Method and system for switching beam forming and MIMO (Multi-Input Multi-Output) beam forming | |
| CN102223168A (en) | Combined transmit beamforming method based on array antenna and MIMO |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20111123 Termination date: 20141108 |
|
| EXPY | Termination of patent right or utility model |