Summary of the invention
The invention provides a kind of communication means and wireless local area network (WLAN) system of in wireless communication system, realizing multi-subscriber dispatching, allow a plurality of users connecting system simultaneously, and take all factors into consideration the up-downgoing business, in the wireless local network two-way communication, can obviously reduce access delay and improve system throughput.
A kind of communication means of realizing multi-subscriber dispatching in wireless communication system provided by the invention is divided at least two subchannels with the physical channel of wireless communication system, carries out the customer service scheduling based on these subchannels, inserts for a plurality of users are parallel; This method comprises: downlink data transmission stage and transmitting uplink data stage, downlink data transmission is based on orthogonal frequency division multiplexing multiple access and multi-user's multiple-input, multiple-output mechanism (OFDMA+MU-MIMO) mechanism, and transmitting uplink data is based on orthogonal frequency division multiplexing multiple access OFDMA or in conjunction with the orthogonal frequency division multiplexing multiple access (OFDMA+TDMA) of time-division;
Wherein the downlink transfer stage is divided into descending multi-user channel detection and channel feedback stage, downlink data transmission and the stage of recognition;
The uplink stage comprises ascending resource distribution, transmitting uplink data and the stage of recognition;
In the uplink stage, access point AP equipment sends multi-user's poll frame, this multi-user's poll frame carries the uplink transmission resource indication information and gives user site, the a plurality of user site that are used for being scheduled simultaneously send the uplink transmission resource of information or data and distribute indication, and this ascending resource indication information comprises the site identity Information ID, continues duration, subchannel map information, time migration and modulation coding mode;
User site is carried out transmitting uplink data according to the uplink transmission resource indication of receiving with OFDMA or in conjunction with orthogonal frequency division multiplexing multiple access (OFDMA+TDMA) form of time-division;
In descending multi-user channel detection and channel feedback stage, AP sends the frame with channel detection indication, this frame carries ascending control information and gives user site, described ascending control information comprises that a plurality of user site that are used for being scheduled simultaneously send the ascending resource distribution indication of information or data, and this uplink transmission resource indication information comprises Site ID, continues duration, subchannel map information and modulation coding mode.
Access point AP equipment is according to the channel condition information of each user site of the user site feedback that receives, and the MU-MIMO user of selected downlink data transmission organizes, and the user in selected user's group sends data.
The present invention also provides a kind of wireless communication system of realizing multi-subscriber dispatching, and the physics letter of wireless communication system comprises two subchannels at least, inserts for a plurality of users are parallel; This system comprises access point AP equipment and at least two user site;
The wherein said downlink transfer stage is divided into descending multi-user channel detection and channel feedback stage, downlink data transmission and the stage of recognition; The described transmitting uplink data stage comprises ascending resource allocated phase, transmitting uplink data and the stage of recognition;
Access point apparatus AP, send multi-user's poll frame in the transmitting uplink data stage, this multi-user's poll frame carries the uplink transmission resource indication information and gives user site, the a plurality of user site that are used for being scheduled simultaneously send the uplink transmission resource of information or data and distribute indication, and this ascending resource indication information comprises the site identity Information ID, continues duration, subchannel map information and modulation coding mode;
AP is in descending multi-user channel detection and channel feedback stage, transmission has the frame of channel detection indication, this frame carries ascending control information and gives user site, described ascending control information comprises that a plurality of user site that are used for being scheduled simultaneously send the ascending resource distribution indication of information or data, and this uplink transmission resource indication information comprises Site ID, continues duration, subchannel map information and modulation coding mode;
Access point AP equipment is according to the channel condition information of each user site of the user site feedback that receives, and multi-user-multiple-input, multiple-output (MU-MIMO) user of selected downlink data transmission organizes, and the user in selected user's group sends data.
User site is carried out transmitting uplink data according to the uplink transmission resource indication of receiving with OFDMA or in conjunction with OFDMA (OFDMA+TDMA) form of time-division.
In the communication means and wireless communication system of in wireless communication system, realizing multi-subscriber dispatching provided by the invention, in the incidentally upstream data request accordingly of descending scheduling stage, and allow access point AP equipment can obtain the service request of end side as early as possible, reduce the polling overhead of follow-up uplink scheduling, help the follow-up uplink scheduling of AP.Like this, the MAC layer scheduling mechanism that allows a plurality of users to insert simultaneously, and take all factors into consideration the up-downgoing business, in wireless communication systems such as WLAN (wireless local area network), realize two-way communication, can obviously reduce access delay and improve system throughput, and satisfy more multimedia service and insert.
Embodiment
The present invention proposes a kind of communication means of realizing multi-subscriber dispatching in wireless communication system, allow a plurality of users access dispatching mechanism simultaneously, and take all factors into consideration the up-downgoing business, in the wireless local network two-way communication, can obviously reduce access delay and improve system throughput, and satisfy more multimedia service and insert.Particularly,, and allow access point AP equipment can obtain the service request of end side as early as possible, reduce the polling overhead of follow-up uplink scheduling, help the follow-up uplink scheduling of AP in can be the incidentally corresponding upstream data request of descending scheduling stage.
Realize the communication means of multi-subscriber dispatching in the wireless communication system provided by the invention, the physical resource of wireless communication system is carried out refinement and multiplexing, insert for a plurality of users are parallel simultaneously, described physical resource comprises time, frequency, space; Comprise: downlink data transmission stage and transmitting uplink data stage.In the embodiment of the invention, downlink data transmission is based on OFDMA+MU-MIMO mechanism, and transmitting uplink data is based on the OFDMA (OFDMA+TDMA) of OFDMA or time-division;
In the specific embodiment, supposing that the AP bandwidth of operation is 80MHz, be equipped with 8 antennas, is that unit divides subchannel with 20MHz, and each subchannel allows 4 of while access customer numbers at down direction at most by MU-MIMO; The maximum number of user that system inserts simultaneously is 8 and is example that the process that has provided work is given an example.Wherein the uplink stage comprises ascending resource allocated phase, transmitting uplink data and the stage of recognition, as shown in Figure 1.In the uplink stage, access point apparatus (AP) sends multi-user's poll frame, this multi-user's poll frame carries the uplink transmission resource indication information and gives user site, be used for the uplink transmission resource distribution indication that user site sends information or data, this ascending resource indication information comprises the site identity Information ID, continues duration, subchannel map information, time migration and modulation coding mode; User site is carried out transmitting uplink data according to the uplink transmission resource indication of receiving with OFDMA or in conjunction with orthogonal frequency division multiplexing multiple access (OFDMA+TDMA) form of time-division; STA confirms the correct data of receiving or the piece affirmation then.
And the downlink transfer stage is divided into descending multi-user channel detection and channel feedback stage, downlink data transmission and the stage of recognition, as shown in Figure 2.In descending multi-user channel detection and channel feedback stage, AP sends the frame with channel detection indication, this frame carries ascending control information and gives user site, described ascending control information comprises that the ascending resource that is used for user site transmission information or data distributes indication, and this uplink transmission resource indication information comprises Site ID, continues duration, subchannel map information and modulation coding mode.Access point AP equipment is according to the channel condition information of each user site of the user site feedback that receives, and the MU-MIMO user of selected downlink data transmission organizes, and the user in selected user's group sends data.AP confirms the correct data of receiving or the piece affirmation then.
In order to reduce overhead, take all factors into consideration the message transmission of up-downgoing, realize the two-way communication between AP and the user site.Introduce the up-downgoing combined dispatching phase of the cycles, shown in Fig. 3 and 4, be divided into three phases this dispatching cycle substantially:
Descending multi-user channel detection and channel feedback stage, downlink data transmission and the stage of recognition and transmitting uplink data and the stage of recognition.
AP sends management frames, the beginning of sign scheduling phase, and carry frequency, bandwidth of operation, the scheduling parameter collection parameter that AP works;
S01, AP sends management frames, carries the corresponding management parameter, identifies the beginning of dispatching cycle;
S10, descending multi-user channel detection and channel feedback stage:
S11, AP select corresponding user's group according to qos parameter professional in the current business formation;
Particularly, AP equipment can be surveyed to carry out subsequent communication channel based on selected downlink user according to the selected corresponding user of parameters such as service priority, stand-by period and/or queue length;
S12 organizes the frame (MU-Sounding+Poll frame) that transmission has multi-user's detection and poll to selected user;
AP equipment sends multi-user's explore frame, and this multi-user's explore frame carries the ascending resource indication information, comprises Site ID, subchannel mapping, continues parameters such as duration and time migration.
S13, the user who is polled to only feed back current channel condition information (CSI) as no upstream data transmission person;
The user who is polled to need feed back CSI and data if any transmitting uplink data person;
Receive the user site of multi-user's explore frame, utilize its assigned resource feeding back channel state information or/and the transmission data, wherein the channel condition information content of feedback determines that according to the channel feedback type of carrying described channel feedback type comprises the feedback of channel feedback, Limited Feedback or the code book of total state.
In multi-user's poll stage, selecting the poll user based on known channel status, paid-in service bandwidth request, is that website distributes uplink transmission resource, and resource allocation result is carried in multi-user's poll frame is broadcast to website.
In descending multi-user channel detection and channel feedback stage, AP sends the frame with channel detection indication, this frame carries ascending control information and gives user site, described ascending control information comprises that the ascending resource that is used for user site transmission information or data distributes indication, and this uplink transmission resource indication information comprises Site ID, continues parameters such as duration, subchannel map information and modulation coding mode.
S20, downlink data transmission and the stage of recognition:
S21, AP select the multi-user MU-MIMO group of downlink data transmission according to the user feedback channel status;
S22, descending multi-user DL-MU-MIMO transfer of data and the stage of recognition, the stage of recognition can be with upstream data slightly;
Access point AP equipment is according to the channel condition information of each user site of the user site feedback that receives, and the MU-MIMO user of selected downlink data transmission organizes, and the user in selected user's group sends data.
S30, transmitting uplink data and the stage of recognition:
S31, according to the service bandwidth request of band slightly in the descending stage, beginning multi-user poll is asked the MU-Poll frame;
S32, transmitting uplink data and the stage of recognition;
Each user site is carried out concurrent transfer of data according to the uplink transmission resource indication of receiving based on the OFDMA/OFDMA+TDMA mode;
The uplink transmission resource that the website utilization is distributed is carried out transmitting uplink data, downlink data affirmation, service bandwidth request or transfer management frame, control frame.
In the transmitting uplink data stage, access point apparatus AP sends multi-user's poll frame, this multi-user's poll frame carries the uplink transmission resource indication information and gives user site, be used for the uplink transmission resource distribution indication that user site sends information or data, this ascending resource indication information comprises the site identity Information ID, continues parameters such as duration, subchannel map information and modulation coding mode;
User site is carried out transmitting uplink data according to the uplink transmission resource indication of receiving with the OFDMA/OFDMA+TDMA form;
Receive the website of downlink data, the ascending resource indication information that carries according to downstream physical frame, adopt the mode feedback acknowledgment information of OFDMA/OFDMA+TDMA or/and carry out transmitting uplink data, wherein a plurality of users on each subchannel adopt the TDMA mode to carry out transmitting uplink data.
Can adopt acquiescence and downlink data transmission same sub-channel to send the affirmation information of downlink data.
S40, AP sends the finishing scheduling frame, sign end dispatching cycle.
Described user site transmission information comprises the service bandwidth request, comprises service flow ID, current business queue length, and being used for AP is that follow-up transfer of data is distributed resource, and described service bandwidth request is carried in the Frame of user site transmission.
Described service bandwidth request is packaged into mac frame separately and transmits.
At described transmitting uplink data and the stage of recognition:
AP sends the affirmation information of upstream data, and confirmation and downlink data frame transmit with polymerization methods;
This confirmation is replied in the OFDMA mode at the subchannel of transmitting uplink data respectively.
Downlink transfer and uplink be combined dispatching in a dispatching cycle, with confirmation and data aggregate transmission.When alternate transmission is carried out in descending transmission and uplink in a dispatching cycle:
Carry the ascending resource indication information in downlink transmission frame: the ascending resource that is distributed comprises the time of channel state feedback/acknowledging time and service bandwidth claim frame at least.
Described multi-user's poll frame, multi-user's explore frame and uplink transmission resource indication information adopt low-order-modulated, Single User MIMO mode to duplicate transmission on a plurality of subchannels.
In dispatching cycle, transmit together for the The data polymerization methods of up feedback/affirmation and up transmission;
From descending, choose relative users, transmission has Multiuser Detection and up poll frame;
AP is according to service priority, stand-by period, and the selected corresponding user's group of qos parameters such as queue length is carried out channel detection and poll;
The multi-user surveys poll frame comprises CSI feedback time and service bandwidth claim frame at least to the resource of uplink assignment time;
Multi-user's poll does not need to design special poll frame (CF-Poll etc.) as 802.11, indicated but ascending control information (UL_SIG) control domain is set in downlink transmission frame.The resource allocation of UL-SIG indication is used for website acknowledge information (ACK), service request or business datum; Wherein bandwidth request can be in Frame incidentally, such as the mac frame head;
Figure 5 shows that the frame structure schematic diagram of descending PPDU, wherein the physics frame head comprises that ((UL-SIG), the data division that carries thereafter are mac frame for leading, Downlink Control Information (DL-SIG) and ascending control information.DL-SIG is used for the control information of demodulation follow-up data, can comprise information such as Site ID, subchannel mapping, modulation coding mode and data length; UL-SIG is used for ascending resource and distributes, and comprises Duration territory, symbol offset, STA number, UL-SIG-IE and the Padding territory of sub-frame of uplink.Wherein the Duration territory of sub-frame of uplink is used for specifying the duration of the sub-frame of uplink of each terminal; Symbol offset refers on each subchannel the time migration between two PPDU; The number of STA refers to the sum of the up STA of this scheduling; UL-SIG-IE has pointed out the uplink channel resources that up each STA distributed indication, and wherein AID is meant at the networking association phase, and unique related ID that AP distributes for each STA that is successfully associated, subchannel shine upon the territory and refer to the subchannel that website distributed dispatched; The MCS territory refers to the space fluxion and the modulation coding mode of adopting of website.
Foregoing multi-user's explore frame, multi-user's poll frame and multi-user survey poll frame can not pass through special definition frame, can realize by DL-SIG and the UL-SIG that is carried in the descending sub frame.
Figure 6 shows that the PPDU frame structure of sub-frame of uplink, comprise leading and data division.
For the downlink data transmission stage, because the user of upstream data, the user of depending on downlink data transmission, so some field in the UL-SIG territory can be omitted, identify such as AID, subchannel mapping (because indicating among the DL-SIG in front), UL can give tacit consent to the identical resource allocation of employing DL.Before finishing dispatching cycle, if downlink transfer has been finished or data not for a long time, and up user's real time business is many, can arrange special up polling cycle again, be that AP sends the MU-POLL frame, according to incidentally service request or polling list in competitive stage or the front downlink transmission process,, carry out transmitting uplink data for different STA distributes bandwidth.
The embodiment of the invention also provides a kind of wireless communication system of realizing multi-subscriber dispatching, and the physical resource of wireless communication system is carried out refinement and multiplexing, inserts for a plurality of users are parallel, and physical resource comprises time, frequency, space; This system comprises access point AP equipment and at least two user site;
The wherein said downlink transfer stage is divided into descending multi-user channel detection and channel feedback stage, downlink data transmission and the stage of recognition; The described transmitting uplink data stage comprises ascending resource allocated phase, transmitting uplink data and the stage of recognition;
Access point apparatus AP, send multi-user's poll frame in the transmitting uplink data stage, this multi-user's poll frame carries the uplink transmission resource indication information and gives user site, be used for the uplink transmission resource distribution indication that user site sends information or data, this ascending resource indication information comprises the site identity Information ID, continues duration, subchannel map information and modulation coding mode;
AP is in descending multi-user channel detection and channel feedback stage, transmission has the frame of channel detection indication, this frame carries ascending control information and gives user site, described ascending control information comprises that the ascending resource that is used for user site transmission information or data distributes indication, and this uplink transmission resource indication information comprises Site ID, continues duration, subchannel map information and modulation coding mode;
Access point AP equipment is according to the channel condition information of each user site of the user site feedback that receives, and multi-user-multiple-input, multiple-output (MU-MIMO) user of selected downlink data transmission organizes, and the user in selected user's group sends data.
User site is carried out transmitting uplink data according to the uplink transmission resource indication of receiving with OFDMA or in conjunction with OFDMA (OFDMA+TDMA) form of time-division.
Access point AP equipment carries out downlink data transmission based on orthogonal frequency division multiplexing multiple access and multi-user-multiple-in-multiple-out OFDM A+MU-MIMO mechanism; User site is carried out transmitting uplink data based on OFDMA or in conjunction with the OFDMA (OFDMA+TDMA) of time-division.
The wireless communication system that provides in the present embodiment, its operation principle and flow process are as previously mentioned substantially, do not repeat them here.
Communication means and the wireless communication system of in wireless communication system, realizing multi-subscriber dispatching provided by the invention, in the incidentally upstream data request accordingly of descending scheduling stage, and allow access point AP equipment can obtain the service request of end side as early as possible, reduce the polling overhead of follow-up uplink scheduling, help the follow-up uplink scheduling of AP.Like this, the MAC layer scheduling mechanism that allows a plurality of users to insert simultaneously, and take all factors into consideration the up-downgoing business, in the wireless local network two-way communication, can obviously reduce access delay and improve system throughput, and satisfy more multimedia service and insert.
Though the present invention with preferred embodiment openly as above; but it is not to be used for limiting the present invention; any those skilled in the art without departing from the spirit and scope of the present invention; can make possible change and modification, so protection scope of the present invention should be as the criterion with the scope that claim of the present invention was defined.