CN101277298A - Method and system for medium access control(mac) rate selection - Google Patents

Abstract

A method and system for medium access control (MAC) rate selection are presented. The system includes at least one processor that enables selection of MAC layer parameter values and/or PHY layer parameter values, to maintain a rate of data transmission of at least one transmitted signal, which is no greater than a selected data transfer rate. The error rate of the one or more transmitted signals may be maintained within a specified range based on the selection for varying signal to noise ratios.

Description

In communication system, handle the method and system of multimedia messages

Technical field

The present invention relates to multi-media communication, particularly a kind of method and system that is used for medium access control (MAC) rate selection.

Background technology

In communication network, data are transmitted between transmitting terminal and receiving terminal by network.Network comprises multiple form with information, bag or frame, transmission data communication media and communication device between reception and transmitting terminal.The multiple agreement that is used to transmit data is arranged.For example, some transport layer data agreements are used for being controlled at the quantity (weighing with bits per second) of time slot transmission data.TCP (transmission control protocol) is one of this quasi-protocol.TCP limits data quantity transmitted in the time slot according to congestion window and/or slowstart algorithm.In the beginning of data flow transmission, the size of congestion window is set at an initial value, to transmit relative small amount of data from transmitting terminal to receiving terminal.Receiving terminal produces a corresponding confirmation signal transmission and postbacks sending end after receiving the data that sent by transmitting terminal.

After receiving corresponding confirmation signal, transmitting terminal just is set at a value bigger than initial value with the size of congestion window, again according to this bigger congestion window transmission data subsequently.Like this, in same time slot, can be smaller transmission more data during congestion window.Bigger congestion window can obtain bigger message transmission rate between transmitting terminal and receiving terminal.Receiving terminal produces corresponding confirmation signal according to the information of receiving, transmitting terminal then continues to increase the size of congestion window according to the affirmation signal of receiving.

When transmitting terminal is not received corresponding confirmation signal, the data of transmitting before then can transmitting again/sending.In addition, transmitting terminal can assert just and exist congestedly in the network that the data before making are not received end and receive, the data of Chuan Songing can be sent out to hold and think " losing " before.The parameter that is used for weighing loss of data has: BER (error rate), FER (Packet Error Ratio), PER (frame error rate).The increase of BER, PER and/or FER can cause the increase of loss of transmitted data amount.

When there was loss of data in identification, transmitting terminal reduced the size of its congestion window.The reducing of congestion window size then can correspondingly reduce the data transmission rate between transmitting terminal and the receiving terminal.In case data transmission rate has reduced, congestion window can increase again subsequently.

A kind of mechanism that is called sliding window protocol utilizes congestion window size to come data quantity transmitted in the restricting time slots.Sliding window protocol is with the data serial number of being transmitted.For given current congestion window size CW _Curr, transmitting terminal sends some data blocks, as, sequence number SEQ is positioned at SEQ _UnAck≤ SEQ≤SEQ _UnAck+ CW _CurrPacket in this scope, wherein SEQ _UnAckBe unacknowledged transmission data block sequence number still.As SEQ＞SEQ _UnAck+ CW _CurrThe time, transmitting terminal just can the delayed delivery data, are identified up to the data block of one or more previous transmissions or a part of data and receive, be i.e. SEQ≤SEQ _UnAck+ CW _CurrThe time send subsequently data again.Under slow starting state, the transmitting terminal that is arranged so that of current congestion window size sends single data block and wait acknowledge earlier, sends data block subsequently again.Thisly send the individual data piece transmits the subsequent data piece again after confirmation signal is received in wait process by transmitting terminal and be known as stop-and-wait protocol.

Some data link layer protocol also is used for the control data transmission rate.MAC layer (by IEEE 802.11n definition) is one of this quasi-protocol.The MAC layer uses stop-and-wait protocol, its parameter influence data transmission rate.For example, when transmitting terminal fails to receive the affirmation signal of receiving terminal when transmitting first, utilize contention window parameter, can determine the number of times that frame retransmits.After the transmission of present frame was identified, when perhaps number of retransmissions reached by the determined maximum of contention window parameter, frame subsequently just can be transmitted.In some MIMO (advancing to have more) (by the IEEE802.11n definition) wireless telecommunication system more, the MAC layer parameter can be determined based on the antenna selection course, NSS transmitting data stream (wherein, NSS 〉=1, be the quantity of data flow) in each Tong Guo NTX transmitting antenna (wherein NTX＞1 is the quantity of transmitting terminal antenna) in one or more transmitting antennas of selecting send.

One or more PHY (physics) layer parameter that transmitting terminal uses can influence the size of BER, PER and/or FER.For example, physical layer parameter comprises: code rate, modulation system such as the 64-QAM of BCC (Binary Convolutional Code) (64 grades of quadrature amplitude modulation).

For example, when code rate reduced to 3/4 by 5/6, data transmission rate reduced, and BER, PER and/or FER also reduce simultaneously.When code rate was increased to 3/4 by 1/2, data transmission rate increased, and BER, PER and/or FER also increase simultaneously.When employed modulation type became 256-QAM by 64-QAM, data transmission rate increased, and BER, PER and/or FER also increase simultaneously.When modulation type when 64-QAM becomes binary phase shift keying (BPSK), data transmission rate reduces, BER, PER and/or FER also reduce simultaneously.In the mimo system of NSS=NTX, when NSS＜NTX, data transmission rate reduces, and BER, PER and/or FER also reduce simultaneously; When NSS＜NTX, one or more data flow can send by more than one transmitting antenna, cause redundant transmission.

The maximum data transmission rate of one end can be by the caused limit decision of transmission data communication media.The largest data transfer speed that medium of communication is supported is called as " linear speed ".

Sent by network in some application of data by transmitting terminal, desired peak data rate is less than linear speed.Thereby, utilize physical layer parameter to reach maximum data transmission rate and unnecessary.In addition, under real-time constraint, send the application of data for some, for example stream-type video, VOIP (networking telephone), retransmitting the time delay that is caused can not stand.

The present invention that said system and the application's further part are introduced in conjunction with the accompanying drawings compares, and existing and limitation and defective conventional method are conspicuous for a person skilled in the art.

Summary of the invention

The present invention relates to be used for the method and system of MAC (media interviews control) rate selection, below at least one width of cloth accompanying drawing, obtained abundant demonstration and/or description, and more completely illustrate in the claims.

According to an aspect of the present invention, the invention provides a kind of method of handling multimedia messages in communication system, described method comprises:

Select MAC layer parameter value and PHY layer parameter value one at least, be not more than the selected data transfer rate with the data transmission rate that keeps at least one transmission signals;

Based on described selection, the error rate of described at least one transmission signals of maintenance is positioned at the scope of appointment at the snr value that changes.

Preferably, described error rate is as the next one at least: the error rate, frame error rate, Packet Error Ratio.

Preferably, the method further comprises: calculate at least one error of calculation rate based on described at least one transmission signals.

Preferably, the method further comprises: more described at least one error of calculation rate and described error rate.

Preferably, the method further comprises: based on described comparison, revise in the MAC layer parameter value of described selection and the PHY layer parameter value value of one at least.

Preferably, described PHY layer parameter value comprises at least as is next: code rate and modulation system.

Preferably, described MAC layer parameter comprises at least as is next: contention window value, be used for sending based at least one spatial flow the determining of number of the transmitting antenna of signal.

Preferably, the method further comprises, is definite execution antenna selection course of the quantity of the described transmitting antenna that is used to send signal, and wherein said transmitting antenna is that described at least one spatial flow sends signal.

According to an aspect of the present invention, the invention provides a kind of machine readable code, computer program of storage comprises at least one code segment on it, is used for handling multimedia messages at communication system, and described at least one code segment is carried out by machine and made machine carry out following steps:

Select MAC layer parameter value and PHY layer parameter value one at least, be not more than the selected data transfer rate with the data transmission rate that keeps at least one transmission signals;

Based on described selection, the error rate of described at least one transmission signals of maintenance is positioned at the scope of appointment at the snr value that changes.

Preferably, described error rate is as the next one at least: the error rate, frame error rate, Packet Error Ratio.Preferably, described machine readable code further comprises the code that is used for calculating based on described at least one transmission signals at least one error of calculation rate.

Preferably, described machine readable code further comprises the code that is used for more described at least one error of calculation rate and described error rate.

Preferably, described machine readable code further comprises and being used for based on the described MAC layer parameter value of relatively revising described selection and the PHY layer parameter value code of the value of one at least.

Preferably, described PHY physical layer parameter value comprises at least as is next: code rate and modulation system.

Preferably, described MAC layer parameter comprises at least as is next: contention window value, be used for sending based at least one spatial flow the determining of number of the transmitting antenna of signal.

Preferably, described machine readable code further comprises the code of definite execution antenna selection course of the quantity that is used to the described transmitting antenna that is used to send signal, and wherein said transmitting antenna is that described at least one spatial flow sends signal.

According to an aspect of the present invention, the invention provides a kind of system that handles multimedia messages in communication system, described system comprises:

At least one processor is used to select MAC layer parameter value and PHY physical layer parameter value one at least, is not more than the selected data transfer rate with the data transmission rate that keeps at least one transmission signals;

Described at least one processor is based on described selection, and the error rate of described at least one transmission signals of maintenance is positioned at the scope of appointment at the snr value that changes.

Preferably, described error rate be following at least one: the error rate, Packet Error Ratio, frame error rate.

Preferably, described at least one processor calculates at least one error of calculation rate based on described at least one transmission signals.

Preferably, more described at least one error of calculation rate of described at least one processor and described error rate.

Preferably, described at least one processor is based on described comparison, revises in the MAC layer parameter value of described selection and the PHY layer parameter value value of one at least.

Preferably, described PHY layer parameter value comprises at least as is next: code rate and modulation system.

Preferably, described MAC layer parameter comprises at least as is next: contention window value, be used for sending based at least one spatial flow the determining of number of the transmitting antenna of signal.

Preferably, described at least one processor is definite execution antenna selection course of the quantity of the described transmitting antenna that is used to send signal, and wherein said transmitting antenna is that described at least one spatial flow sends signal.

In description and accompanying drawing subsequently, will more fully understand lot of advantages of the present invention, aspect and new feature and specific embodiment.

Description of drawings

Fig. 1 is the schematic block diagram according to the wireless telecommunication system of the embodiment of the invention;

Fig. 2 A is the schematic block diagram according to the transceiver circuit of the embodiment of the invention;

Fig. 2 B is the structural representation block diagram according to the MAC layer rate selection of the embodiment of the invention;

Fig. 3 is the schematic block diagram according to the MIMO sender system that is used for MAC layer rate selection of the embodiment of the invention;

Fig. 4 is the signal Protocol REference Model according to the protocol interaction that is used for MAC layer rate selection of the embodiment of the invention;

Fig. 5 is the flow chart according to the MAC layer rate selection step of the embodiment of the invention.

Embodiment

Enforcement of the present invention is embodied in the method and system of realizing MAC (media interviews control) rate selection.Native system is used for handling the communication system multimedia messages, comprising: the reflector of control MAC layer and/or PHY layer in wireless telecommunications system, it is used to select MAC layer and/or PHY layer parameter value.Set MAC layer and/or PHY physical layer parameter value, make transmitting terminal send data, and error rate is remained in the particular range with selected message transmission rate.Error rate can be weighed with the error rate (BER), Packet Error Ratio (PER) and/or frame error rate.In various embodiment of the present invention, PHY layer and/or MAC layer parameter value are set so that the BER and/or the FER of PHY layer and/or MAC layer minimize, to reduce the possibility that TCP starts slowly.

Fig. 1 is the block diagram of a typical radio communication system of the embodiment of the invention.Comprise mobile computer system 102, streaming media server 104, mobile phone 106, smart mobile phone 108, MIMO (advancing to have more) communication system 110 among Fig. 1 more.Wherein MIMO communication system 110 can be used for sending and/or receiving one or more signal 110a and 110b.

Mobile computer system 102 comprises the MIMO communication system, makes that mobile computer system 102 can be simultaneously by one or more transmission signal transmitted data, and/or receives data by one or more received signals simultaneously.The user can utilize mobile computer system 102 to carry out various programs and/or application, for example: Email, WWW World Wide Web (WWW), browser, DBAR database access routine, VOIP (internet protocol voice technology) and/or media record and player.

Streaming media server 104 can store one or more video/audio programs, Multimedia Program and/or data. Streaming media server 104 and 110 couplings of MIMO communication system, just can send data and/or media stream simultaneously by the signal 110a and the 110b of one or more transmissions, and/or receive data and/or media stream simultaneously by the signal 110a and the 110b of one or more receptions.

Mobile phone 106 can be used to by wireless communication medium send and/receive voice, data and/or multi-media communication.In addition, mobile phone can be used to transmission/reception text message and/or browse WWW.

Smart phone 108 can be realized the function similar with mobile phone 106.Smart phone 108 can be used for transmission/received signal 108a.In addition, smart phone 108 is the function of attainable palmtop PC also, for example PDA (personal digital assistant).Smart phone 108 attainable PDA functions comprise: management name and address database, individual calendar, do list and memo.

Signal 110a, 110b and/or 108 can send by the wireless communication medium of sharing.Signal 110a is subjected to the interference of signal 110b and 108b, and in addition, signal 110b is subjected to the interference of signal 110a and 108b.Similarly, signal 108a is subjected to the interference of signal 110a and 110b.MIMO sends communication system 110 and can utilize beam shaping to remove interference between MIMO receiving end signal 110a and the 110b.Signal 110a and 110b can send to avoid interference by the frequency range that is different from signal 108a.Yet, when a plurality of MIMO transmitting systems 110 trials send signal simultaneously by universal frequency or frequency range, exist between the signal of transmission and disturb.This kind interference is called as conflict.MAC layer in the MIMO communication system 110 can detect conflict.For example, the data that send by mac frame can be corrected in collision or be destroyed.For conflict, the MAC layer can be carried out certain strategy, for example retransmits based on congestion window parameter.

Even when disturbing and/or conflict when not existing, by the data that signal 110a, 110b and/or 118a send, also may be owing to the nonlinear characteristic of wireless telecommunication system is destroyed in transmission.This non-linear nature is called as fading channel.Wireless communication medium is in smooth attenuation channel, and its nonlinear characteristic is similar substantially in a frequency range; And in the smooth attenuation channel of selectivity, its nonlinear characteristic changes in a frequency range.Decay can make receiving terminal for example mobile computer system 102 detect the error code that sends data.The speed that error code takes place is weighed with the error rate (BER) statistical value.The error code that receives in the data can cause receiving terminal to detect mistake frame and/or mistake bag.The speed that the mistake frame takes place is weighed with frame error rate (FER), and the speed that the mistake bag takes place is weighed with Packet Error Ratio (PER).

Transmitting terminal, for example MIMO communication system 110 and/or streaming media server 104 when the affirmation information of not receiving corresponding to transmit frame and/or bag before, just can detect the generation of error code, mistake frame and/or mistake bag.Transmitting terminal just can contrast the quantity that received frame and/or bag are determined information according to the quantity of frame that has sent and/or bag, calculates FER and/or PER.Based on the amount of bits that sends in certain time slot, transmitting terminal can also calculated data transfer rate (being weighed by bps (bps)).

In different embodiments of the invention, the user can select data transmission rate to be used for sending voice, multimedia and/or data from transmitting terminal.Based on the application of using, can determine the scope of target BER, FER and/or PER.But this target zone comprises the acceptance error rate scope of this application.Transmitting terminal sends signal based on one group of initial PHY layer parameter value and/or MAC layer parameter value.The PHY physical layer parameter comprises code rate, modulation and modulation system.The MAC layer parameter comprises contention window size.

Transmitting terminal then can calculate BER, FER and/or PER according to the data that send.The BER that calculates, FER and/or PER value are compared with corresponding target BER, FER and/or PER value.When calculate BER, FER and/or PER value in corresponding target zone the time, transmitting terminal then keeps existing P HY layer parameter and/or MAC layer parameter.When calculate BER, FER and/or PER value not in corresponding target zone the time, transmitting terminal is then selected one or more new PHY layer parameter values and/or MAC layer parameter value.

Different embodiments of the invention can be used in the open cycle system, and the transmitting terminal in this system calculates BER, FER and/or PER value according to the data that send, then according to calculate value, selection PHY layer parameter and/or MAC layer parameter.Different embodiments of the invention also can be used in the closed-loop system, and the transmitting terminal in this system receives the feedback information from receiving terminal.For example, closed-loop system can be used in conjunction with the antenna selection course.For example, (NTX＞NSS), the antenna selection course selects transmitting antenna to send selected data stream during greater than the quantity that sends data flow when the quantity of transmitting antenna.

Fig. 2 A is the schematic block diagram according to the transceiver circuit of the embodiment of the invention.Memory processor 272, transceiver 274, radio-frequency front-end 280, one or more reception antenna 276a have been shown among Fig. 2 A ..., 276n, one or more transmitting antenna 278a ..., 278m.Transceiver 274 comprises processor 282, receiver 284 and reflector 286.

Memory 272 is realized by one or more transmitting antenna 278a, ..., data that 278m sends, by one or more reception antenna 276a ..., the storage of the data that 276n receives and/or obtain, and/or realize being used to controlling the storage of code of the operation of transceiver 274.In mimo system, transmitting antenna 278a ..., the quantity of 278m is determined according to parameter N TX.In mimo system, reception antenna 276a ..., the quantity of 276n is determined according to parameter N RX.The value of each NTX and NRX all is a numeral, such as an integer.

Processor 282 can be realized the function of digit receiver and/or transmitter according to the communication standard that is suitable for.These functions can include, but is not limited to the low layer task of execution in the related protocol reference model.These low layers comprise PHY layer and/or MAC layer.These tasks further comprise: Physical layer convergence protocol (PLCP), related sublayer (PMD) function of physical medium and relevant layers management function.

Receiver 284 can be realized the digit receiver function, includes, but is not limited to fast fourier transform, equilibrium, goes mapping, demodulation control, release of an interleave, separates punching (depuncture), decoding.Transmitter 286 can be realized the digit emitter function, includes, but is not limited to coding, shrinks, interlocks, shines upon, modulates control and invert fast fourier transformation.In mimo system, transmitter 286 can be realized beam shaping.Radio-frequency front-end 280 passes through one or more antenna 276a ..., 276m can receive analog radio-frequency signal, and it is transformed into base band, and the analog baseband signal generation numeral for receiving.This numeral can be a plural number, comprises two components of I, Q.Radio-frequency front-end 280 can also pass through one or more antenna 278a ..., 278m sends analog radio-frequency signal, and wherein digital baseband signal is converted into analog radio-frequency signal before transmission.

In service, processor 282 receives data from receiver 284.Processor 282 with the deposit data received in memory 272, so that follow-up analysis and/or processing.Processor 282 can also take out data from memory 272.The data of this taking-up are sent by the radio-frequency channel by transmitter 286.Processor 282 is that one or more MAC layers and/or PHY layer select parameter value to send data.In different embodiments of the invention, these one or more MAC layers and/or PHY layer parameter value are selected according to selected data transmission rate and BER, FER and/or PER target range.

Fig. 2 B is the structural representation block diagram according to the MAC layer rate selection of the embodiment of the invention.Processor 210, sending module 215 are arranged as shown in Fig. 2 B.Wherein, sending module 215 comprises: source code module 220, memory module 222, source layer multiplexer module 224, PHY/MAC module 226, stride layer dispenser 228, parameter control module 230 and transmitting antenna 232a ..., 232b.

Source code module 220 comprises adaptive logic, circuit and/or code, is used to transmit preceding packed data.For example, the data after the compression can be the video data of MPEG-4 form.Source code module 220 can transmit the information of the data after the relevant compression to striding a layer dispenser module 228.The information that transmits is relevant with compression type.For example, if the data after the compression comprise video data, 220 of source code modules transmit specific compression types, as MPEG-1, MPEG-2, MPEG-4, H.261, H.263 or H.264.Source code module 220 can also transmit employed colourity sampling (chroma subsampling) type, such as 4-4-4,4-2-2 or the sampling of 4-2-0 colourity.

Source layer multiplexer module 224 comprises adaptive logic, circuit and/or code, be used for from memory 222 reading of data, and the various piece of transmission data given PHY/MAC 226.In the MIMO communication system, data can be according to being divided into a plurality of parts from striding layer information of dispenser module 228.Every part will data flow transmitted or spatial flow corresponding to one.For example, can be used for determining the quantity (NSS) of spatial flow from striding layer information of dispenser module 228.

PHY/MAC module 226 comprises adaptive logic, circuit and/or code, and the input data that are used for the converting digital form are with the analogue data of output after suitably modulating, so that send.For example, PHY/MAC module 226 is carried out the FEC coding to digital data.PHY/MAC module 226 also can be carried out specific rf modulations to this analog signal, and this analog signal is come by digital data conversion, and by at least one transmitting antenna 232a .., 232b sends.In the MIMO communication system, use PHY/MAC module 226 that the spatial flow that sends is carried out beam shaping, and each signal allocation through beam shaping is arrived at least one transmitting antenna 232a ..., on the 232b.

In one embodiment of the present of invention, PHY/MAC module 226 can receive one or more digital data streams.Then, PHY/MAC piece 226 is operated these one or more data flow under the indication of for example parameter controll block 230.Accordingly, PHY/MAC module 226 can be carried out specific FEC coding to each digital stream.In mimo system, a plurality of digital streams generate corresponding a plurality of signals through beam shaping through beam shaping.Each digital stream, and/or, be converted into analog radio-frequency signal then through the signal of beam shaping, this can be modulated by specific rf modulations scheme.Radiofrequency signal after each modulation is sent to one or more antennas so that send then.

Stride a layer dispenser module 228 and comprise adaptive logic, circuit and/or code, be used for determining the quantity of spatial flow, will be divided into NSS spatial flow from the data that memory block 222 is taken out.In the MIMO communication system, NSS 〉=1.

In the MIMO communication system, to stride layer dispenser module 228 and also can inform source layer multiplexer module 224, which part of the data of fetching from memory module 222 will be distributed to the spatial flow of each NSS＞1.The corresponding space of source layer multiplexer module 224 transmission flows to PHY/MAC module 226.Stride layer dispenser module 228 and then PHY layer parameter value and/or MAC layer parameter value are transferred to parameter control module 230, be used to handle spatial flow.

In the MIMO communication system, specific data stream is sent to specific transmitting antenna.Stride layer dispenser 228 and have about from each transmitting antenna 232a ..., 232b is to the information of the transmission channel of reception antenna.Wherein by the data of a transmitting antenna transmission, the data than sending from another transmitting antenna can receive with error code still less.Correspondingly, such information can be used for determining which transmitting antenna the sort of data combination of one or more spatial flows should send by.The data combination of these one or more spatial flows is called as wave beam and becomes.The information of the sendaisle of relevant each transmitting antenna can generate from the feedback information of receiving terminal.Perhaps, generate the required feedback signal of this information from receiver, itself and sending module 215 are positioned at same place.

Parameter control module 230 comprises adaptive logic, circuit and/or code, is used to control various operations to digital data in the PHY/MAC module 226.For example, parameter controll block 230 can determine to be used to handle by PHY/MAC piece 226 the FEC coding and/or the rf modulations of particular data.Be routed to specific antenna by the data in the control PHY/MAC module 226, parameter control module 230 can also be used for determining which antenna is used to send which part of data.

In different embodiments of the invention, based on the target range of selected data transfer rate and BER, FER and/or PER, parameter controll block 230 selects parameter value to control the operation of PHY/MAC module 226.According to sending BER, FER and/or the PER value that calculated signals goes out, parameter control module 230 is selected parameter value for for example code rate, modulation system, a day line options based on PHY/MAC module 226.By selecting certain value, make sending module 215 send voice, multimedia and/or data with selected data transmission rate, BER, FER that realization simultaneously calculates and/or PER are in corresponding BER, FER and/or PER target range.The value of selecting can send PHY/MAC module 226 to, uses this to be worth the signal that sends subsequently by it.

In different embodiments of the invention, can select independent code rate and independent modulation system.Selected code rate and modulation system can be used for each in NSS the spatial flow.In other embodiments of the invention, code rate and/or modulation system can be selected adaptively.In the system of utilization adaptive coding, can select separately code rate individually in NSS the spatial flow each, be the code rate that the code rate that is used for a spatial flow is different from another spatial flow.In the system of utilization Adaptive Modulation, the modulation system that is used for a spatial flow is different from the modulation system of another spatial flow.

Be in operation, the data after source encoder module 220 packed datas and the storage compression are in memory module 222.For simplicity, Output1 data and Outputn data are sent by transmitting antenna 232a and 232b respectively.Source code module 220 can transmission information be striden a layer dispenser module 228, informs that the data after the compression are the video data of MPEG-4 form.Source code module 220 for example can also transmit storage corresponding to the beginning of the video data of a frame and the frame type that finishes holder address, frame number and may store.Frame type comprises: I-frame (intraframe coding), P-frame (interframe encode), B-frame (bi-directional predicted frames).Other can information transmitted also have for example colourity sampling form.

Stride layer dispenser module 228 and can determine the quantity NSS of spatial flow, be used for segmenting video data.Each part of video data all is assigned to one of them spatial flow.In the MIMO communication system of utilization transmit diversity, the number of spatial flow can be less than transmitting antenna number, i.e. NSS＜NTX.Source layer multiplexer 224 can be from memory module 222 reading of data, and by the relevant data of Output1 output and spatial flow 1, export the data relevant with spatial flow n by Outputn, and wherein n promptly equals NSS.

Striding layer dispenser module 228, also can to send parameter control module 230 to will be the operation that Output1 and Outputn carry out to each data flow.For example, parameter control module 230 can be MAC layer and/or PHY layer parameter selection parameter value.Can and use consistent MAC layer and/or PHY layer parameter value at each selection in NSS the spatial flow, or can adaptively selected MAC layer and/or PHY layer parameter value.

Stride layer dispenser module 228 can with 230 communications of parameter control module, inform it at data Output1 of high priority utilization QPSK (quarternary phase-shift keying (QPSK)) rf modulations, rather than 16QAM (16 ary quadrature Modulation and Amplitude Modulation) rf modulations.The QPSK rf modulations has littler data throughout than 16QAM.Yet in a given transmission environment, the QPSK rf modulations is more reliable.In addition, transmitting antenna 232a is than the transmission more reliable performance of transmitting antenna 232b.Become if send environment, when making transmitting antenna 232b, then striden the data that layer dispenser module 228 can the indication higher priority and export by Outputn than the transmission more reliable performance of 232a.

When striding layer dispenser module 228 when selecting MAC layers and/or PHY layer parameter value, also can be taken into account from the feedback information of receiving terminal.When 215 pairs of NSS spatial flows of sending module are carried out beam shaping, also can use this feedback information.In different embodiments of the invention, to stride a layer dispenser module 228 and also can utilize the feedback information of passing back from receiver 284, receiver 284 is positioned at transceiver 274 with transmitter 286.From the feedback information of receiver, can be transferred to the sending module 215 that is positioned at same place by receiver.For example, the feedback data that processor 210 is handled from the receiver of same position, the transmission of feedback information after will handling again is to sending module 215.These information can be used for for example controlling the operation of 226 pairs of data flow of PHY/MAC module.

The applying date is the detailed description that the U.S. Patent application 11/327,690 on January 6th, 2006 provides the feedback of relevant mimo system, at this it is introduced among the application in full.

Fig. 3 is the schematic block diagram according to the MIMO sender system that is used for MAC layer rate selection of the embodiment of the invention.Comprise among Fig. 3: transmitter 300, processor 342, memory 340 and a plurality of transmitting antenna 315a ..., 315m.Transmitter 300 comprises: channel coding module 302, punching module (puncture) 304, space analysis device 305, a plurality of frequency interlacing module 306a; ...; 306n, a plurality of mapping block 308a that troops; ...; 308n, a plurality of deserializer 309a; ...; 309n, beam shaping matrix module 312, a plurality of IFFT (fast Flourier inversionization) module 310a; ...; 310m, a plurality of insertion GI (protection is at interval) window module 311a ..., 311m, a plurality of RF front-end module (RFE) 314a; ..., 314m.

Channel coding module 302 comprises adaptive logic, circuit and/or code, and it utilizes forward error correction (FEC) technology to realize the conversion of the binary system input block receive, for example utilizes binary system convolutional encoding (BCC).The utilization of FEC technology is also referred to as chnnel coding, by affix redundant information before the input data are by the radio-frequency channel transmission, can improve the receiver data recovery capability.The ratio of the data block Nepit number after the bit number in the binary system input block and the conversion is encoding rate (coding rate).This encoding rate R is by i _b/ t _bExpression, wherein t _bRepresent the total number of bits among the coded-bit group, i _bRepresentative is included in bit groups t _bIn the sum of information bit.t _b-i _bAmount of bits just represent redundant bit, this redundant bit can make receiver 284 detect and be corrected in the mistake of being introduced from transmitter 286 transmission information to the process of receiver 284 by wireless communication medium.Increase the quantity of redundant bit, can improve the ability that receiver detected and proofreaied and correct the mistake in the information bit that receives.Increase the quantity of redundant bit, can increase t _bValue, and do not increase the quantity i of information bit _b, and correspondingly reduce encoding rate R.The low encoding rate R that produces compares with higher encoding rate R, is called as the encoding rate of " stronger ".Stronger code rate is also corresponding to stronger error confinement mechanism.Stronger error confinement mechanism can correspondingly realize the ability of the mistake in the information bit that detection that receiver is stronger and correction receive.Reduce the quantity of redundant bit, can reduce t _bValue, and do not reduce the quantity i of information bit _b, and correspondingly increase encoding rate R.The higher encoding rate R that produces compares with lower encoding rate R, is called as the encoding rate of " more weak ".

The present invention is not limited to BCC, and the present invention can also adopt following any coding techniques, for example Turbo code, LDPC low density parity check code or various block encoding technique such as Read-Solomon (Reed-Solomon) FEC the coding etc.

Punching module 304 comprises adaptive logic, circuit and/or code, by removing the redundant bit in the binary system input block after the conversion of receiving, changes the encoding rate of the coded data that is received.For example,, can include 2 information bits for based on each continuous 4 bit data block in the reception data of R=1/2 encoding rate BCC coding, and 2 redundant bits.For example, by removing 1 redundant bit in these group of 4 bit of receiving, punching module 304 can make code rate into R=2/3 by R=1/2.

Space analysis device 305 comprises adaptive logic, circuit and/or code, and the data bit piece that is used for being associated with individual bit stream is divided into the data bit piece of a plurality of parsings, and wherein each all is associated with corresponding a plurality of parsing bit streams.This individual bit stream comprises the data of extracting from memory 222.Each is resolved bit stream and is called as spatial flow.Spatial flow includes discernible bit block, and it can be handled in mimo system.

Space analysis device 305 can receive and this individual bit stream b _DbThe data bit piece that is associated, a plurality of parsing bit stream of regeneration b _St[i], the wherein index of i for specific parsing bit stream is identified from a plurality of parsing bit streams.The number range of index i is expressed from the next:

0≤i≤Nss-1 (1)

Wherein Nss represents the number of spatial flow, and for example Nss=2 represents to comprise in the mimo system 2 spatial flows.

Each resolves bit stream b _St[i] comprises this individual bit stream b _DdIn a part of bit.This individual bit stream b _DdComprise a plurality of bits, be included in corresponding a plurality of parsing bit stream b in these a plurality of sets of bits _StIn [i].

Various embodiment of the present invention is not limited to the specific method from individual bit flow distribution bit to a plurality of spatial flows.For example, for the given N that receives from individual bit stream _TOTThe bit block of individual bit, space analysis device 305 distributes about N _TOT/ N _SSBit is to N _SSEach spatial flow in the individual spatial flow.For example, bit stream b _DbFirst N _TOT/ N _SSBit block is distributed to 1, the second N of spatial flow _TOT/ N _SSBit block is distributed to spatial flow 2, the N _SS ^ThIndividual N _TOT/ N _SSBit block is distributed to spatial flow N _SSPerhaps, will be from bit stream b _Db(the wherein k representative and this bit stream b of K bit _DbThe index of the bit in the data bit piece that is associated) distribute to spatial flow i, be shown below:

K _i＝floor(k/Nss)+k?mod(Nss) (2)

K wherein _iThe index of the bit of i spatial flow is distributed in expression, and floor (x) representative is not more than the integer of X, and it is the modulus of mould with y that y mod (x) represents x.

Frequency interleaver 306a comprises adaptive logic, circuit and/or code, is used for rearranging the bit-order of the bit block relevant with the spatial flow that receives.Frequency interleaver 306a can utilize various displacements to rearrange bit-order in the bit block.After rearranging, with i the bit block b that interweaves that spatial flow is relevant _St[i] ^IntCan be divided into a plurality of sub-piece b _Sub[f], wherein f represents frequency.This frequency is corresponding to one in a plurality of carrier frequency carrier waves, and these carrier frequency carrier waves are used for sending by wireless communication medium the representative of the bit of sub-piece.This bit representative can be called as symbol.Each sub-piece b _Sub[f] comprises piece b _St[i] ^IntIn a part of bit.Bit block b _St[i] ^IntComprise a plurality of bits, these a plurality of bits are included in corresponding a plurality of sub-piece b _SubIn [f].

Frequency interleaver 306n comprises adaptive logic, circuit and/or code, is used for rearranging the bit block bit-order relevant with the spatial flow that receives, and is similar to frequency interleaver 306a.In different embodiments of the invention, frequency interleaver 306a ..., the number of 306n can equate with the number N ss of spatial flow.

The mapping block 308a that troops comprises adaptive logic, circuit and/or code, be used for received, the bit relevant with spatial flow be mapped as one or more symbols.The bit that receives can be encoded based on FEC, is called as coded-bit.The mapping block 308a that troops can receive one or more coded-bit b _Sym[f] then based on the modulation system relevant with this spatial flow, generates symbol sym[f].With b _SymThe number of the coded-bit that [f] is relevant can be determined based on modulation system.Symbol sym[f] expression, can be the plural number that comprises homophase I and quadrature Q component.With one or more coded-bit b _Sym[f _k] each relevant symbol sym[f _k] and carrier frequency carrier wave f _kRelevant, the index of the k frequency that to be sign relevant with k carrier frequency carrier wave wherein, this frequency carrier is used for by wireless communication medium transmission sign format.

Typical case's modulation system comprises that two-phase phase shift key moves (BPSK), the quaternary phase shift key moves (QPSK), 16 ary quadrature Modulation and Amplitude Modulation (16QAM) and 256 ary quadrature Modulation and Amplitude Modulation (256QAM).In the BPSK modulation system, for each frequency carrier f _k, the numerical statement of the coded-bit relevant with symbol is shown: num (b _Sym[f _k])=1.In the QPSK modulation system, for each frequency carrier f _k, the numerical statement of the coded-bit relevant with symbol is shown: num (b _Sym[f _k])=2.In the 16QAM modulation system, for each frequency carrier f _k, the numerical statement of the coded-bit relevant with symbol is shown: num (b _Sym[f _k])=4.In the 64QAM modulation system, for each frequency carrier f _k, the numerical statement of the coded-bit relevant with symbol is shown: num (b _Sym[f _k])=6.In the 256QAM modulation system, for each frequency carrier f _k, the numerical statement of the coded-bit relevant with symbol is shown: num (b _Sym[f _k])=8.，

Spatial flow comprises a plurality of frequency carrier N _SD, for example, the 20MHz radio-frequency channel comprises N _SD=56 frequency carrier f _-28, f _-28..., f _-1, f ₁..., f ₂₇And f ₂₈, be used to send coded-bit; The 40MHz radio-frequency channel comprises N _SD=112 frequency carrier f _-56, f _-55..., f _-1, f ₁..., f ₅₅And f ₅₆, be used to send coded-bit.In mimo system, symbol sym[f _-28], sym[f _-27] ..., sym[f _-1], sym[f ₁] ..., sym[f ₂₇], and sym[f ₂₈], perhaps sym[f _-56], sym[f _-55] ..., sym[f _-1], sym[f ₁] ..., sym[f ₅₅], and sym[f ₅₆], all be called as OFDM (OFDM) symbol.The number of coded-bit is relevant with the OFDM symbol, N _CBPS=N _SD* b _Sym[f _k].The number of data bit is relevant with the OFDM symbol, N _DBPS=R*N _SD* b _Sym[f _k], wherein R represents encoding rate.

The mapping block 308a that troops comprises adaptive logic, circuit and/or code, is used for bit relevant with spatial flow, that receive is mapped as one or more symbols, is similar to the mapping block 308a that troops.In different embodiments of the invention, the number 308a of the mapping block of trooping ..., 308n can equate with the number N ss of spatial flow.

Deserializer module 309a comprises adaptive logic, circuit and/or code, is used for a plurality of bits of serial received, and exports a plurality of bits that serial received arrives subsequently simultaneously.Deserializer module 309a comprises the register that is fit to suitable reservoir, latch and/or realizes string and translation function.

Deserializer module 309n comprises adaptive logic, circuit and/or code, is used for a plurality of bits of serial received, and exports a plurality of bits that serial received arrives subsequently simultaneously, is similar to deserializer module 309a.In different embodiments of the invention, the number 309a of deserializer module ..., 309n can equate with the number of spatial flow Nss.

Beam shaping matrix module 312 comprises adaptive logic, circuit and/or code, is used to handle a plurality of spatial flows of receiving, and generates the corresponding a plurality of signals that sent by MIMO transmitter 202 simultaneously.The signal of each generation comprises at least one weighted sum of at least a portion in a plurality of spatial flows that receive.The calculating of weighted sum can be at each frequency carrier f _kCarry out.Each signal indication that generates from each weighted sum is X[f _k].According to channel estimate matrix, beam shaping matrix module 312 can generate corresponding a plurality of signal.This channel estimate matrix can be estimated fading channel based on the feature of wireless communication medium.For example, in closed-loop system, channel estimate matrix can calculate based on the feedback information that is transmitted by receiver, or the signal of receiving according to receiver 284 (being positioned at same place with transmitter 286) calculates.

IFFT module 310a comprises adaptive logic, circuit and/or code, is used for signal frequency-domain form X[f] be transformed into time domain form X (t).Correspondingly time-domain signal comprises a plurality of OFDM symbols.To with corresponding signal X[f] frequency component use the IFFT algorithm, can calculate the OFDM symbol based on this.For example, when handling the 20MHz radio-frequency channel, IFFT module 310a can use 64 IFFT algorithms; When handling the 40MHz radio-frequency channel, use 128 IFFT algorithms.A kind of typical method of OFDM sign computation can find in the 17.3.5.9 bar of ieee standard 802.11a-1999 (R 2003).

Time domain form X (t) comprises the time domain form x of a plurality of signals _j(t), send by MIMO transmitter 202 simultaneously, as shown in the formula:

$X\left(t\right)=\left[\begin{array}{c}{x}_0\left(t\right)\\ x_1\left(t\right)\\ .\\ .\\ .\\ x_{N_{\mathrm{TX}}-1}\left(t\right)\end{array}\right]...\left(3\right)$

Each signal x _j(t) comprise and the N that sends simultaneously from MIMO transmitter 300 _TXA plurality of OFDM symbols that j signal in the individual signal is relevant.At N _TXJ signal x in the individual signal that sends simultaneously _j(t) the OFDM symbol that sends in can be in time sends in mode serially.A period of time T is striden in the transmission of each OFDM symbol _SYM, be called mark space, for example T _SYM=4 μ s.

IFFT module 310m comprises adaptive logic, circuit and/or code, is used for signal frequency-domain form X[f] be transformed into time domain form X (t), be similar to IFFT module 310a.In different embodiments of the invention, IFFT piece 310a ..., the number of 310m can with the number N of generation signal _TXEquate.

Insert GI window module 311a and comprise adaptive logic, circuit and/or code, be used for a plurality of signal x that send by MIMO transmitter 300 _jOne of (t) insert protection between at interval.The protection interval T _GIExpression opening time interval the top from current OFDM mark space end to an OFDM mark space subsequently.After the mark space end of current OFDM symbol, then can be protection period T blanking time _GI, for example, T _GI=0.8 μ s.After the protection gap, promptly be the gap of symbol subsequently corresponding to subsequently OFDM symbol.

Insert GI window module 311m and comprise adaptive logic, circuit, and/or code, be used for a plurality of signal x that send by MIMO transmitter 300 _jOne of (t) insert protection at interval, be similar to and insert GI window module 311a.In different embodiments of the invention, insert GI window module 311a ..., the number of 311m can with the number N of generation signal _TXEquate.

RFE module 314a comprises adaptive logic, circuit and/or code, is used for generating radiofrequency signal from the generation signal of receiving.Radio-frequency module 314a receives the baseband signal that generates.RFE module 314a utilizes a plurality of frequency carrier signal to modulate the baseband signal of receiving, to generate radiofrequency signal.Modulated signal sends by antenna 315a.RFE module 314a can generate the radiofrequency signal of 20MHz, the perhaps radiofrequency signal of 40MHz.

RFE module 314m comprises adaptive logic, circuit and/or code, is used for generating radiofrequency signal from the generation signal of receiving, is similar to RFE module 314a.By sending by antenna 315m that REF module 314m generates through modulation signal.In different embodiments of the invention, REF module 314a ..., the number of 314m can with the number N of generation signal _TXEquate.

Processor 342 comprises adaptive logic, circuit and/or code, is used to make transmitter 300 to carry out sending function according to the communication standard of using.These functions comprise the task that (but being not limited to) low layer is realized, for example, and PHY layer in the related protocol reference model and MAC layer function.These tasks comprise physical layer function, as PLCP (Physical layer convergence protocol), PMD (physical medium is relevant) and/or relevant layer-management function.Processor 342 can also generate the source information bit and/or take out the source information that stores, and these information will be encoded subsequently, shine upon, and transmit by wireless medium again.Processor 342 can also calculate the value corresponding to the beam shaping factor, and these values are used for signal calculated X[f in the beam shaping matrix 312 _k].

Memory 340 comprises adaptive logic, circuit and/or code, is used to store and/or the representation of taking-up information and/or information, for example, comprises the binary representation form of bit.Memory 340 can the storage source information bit.The physical resource that the source information bit that stores can be assigned in the memory 340 stores.Can fetch after the stored source information bit.The source information bit of carrying back is transferred to and memory 340 other equipment, parts and/or subsystems direct or communicative couplings at interval by memory 340 outputs again.Memory 340 can make stored source information bit keep store status, and/or makes it be in the state that can fetch subsequently, is disengaged distribution up to the source of this memory location.According to what received, i.e. the instruction of the source information bit that memory 340 stores is wiped in indication, or this physical resource is distributed to the instruction of the storage of binary message subsequently according to what receive, can remove this physical resource and distribute.Memory 340 can utilize multiple storing media technology, as volatile memory, and for example RAM (random access memory), and/or nonvolatile memory, for example EEPROM (EEPROM (Electrically Erasable Programmable Read Only Memo)).

In the operating process, processor 342 can send to instruction memory 340.These instructions can be fetched the multimedia messages that stores in the memory 340.This multimedia messages comprises voice, video, and/or data message.Processor 342 also receives specific input information, is used for determining the employed data transmission rate of transmission multimedia messages.

In one embodiment of the present of invention, the multimedia messages of being fetched comprises the encode video information of MPEG-1 form or MPEG-2 form.The MPEG video information is transmitted under real-time constraint.Like this, processor 342 can content-based type dispose MAC layer and/or PHY layer parameter value.For example, processor 342 is set a value for contention window parameter, makes that mac layer frame can not retransmit when the affirmation information of the mac frame that sends is not before received.Processor 342 configuration transmitters 300 utilize the transmitter diversity calculated to guarantee BER, FER and/or PER value drop in target zone accordingly.In utilizing the MIMO communication system of transmitter diversity, the number N of spatial flow _SSThe number N that can be less than transmitting antenna _TXProcessor 342 based on calculate channel estimation value, N _SSAnd N _TXDispose beam shaping matrix 312.N _TXValue determine by the antenna selection course.The data rate that transmitter 300 sends signal is less than or equal to the data designated transmission rate.When transmitter 300 utilizes single transmitting antenna, i.e. N _TX=1, data rate refers to the data rate of the signal that is sent by single transmitting antenna.When transmitter 300 utilizes a plurality of transmitting antenna, i.e. N _TX＞1, data rate refers to the data rate sum of each signal that is sent by each transmitting antenna.

Correspondingly, processor 342 can be selected PHY layer parameter value.Processor 342 selects to be used to the N that encodes can for punching module 304 _SSThe encoding rate of each spatial flow in the individual spatial flow.In addition, processor 342 can dispose punching module 304 to use adaptive coding, so, all select and use an encoding rate at each spatial flow, and the encoding rate of a spatial flow can be different from the encoding rate of another spatial flow.

Processor 342 is each mapping block 308a that troops ..., 308n selects employed modulation system.Perhaps, processor can be each mapping block 308a that troops adaptively ..., the 308n selecting modulation mode makes an employed modulation system of spatial flow be different from the employed modulation system of another spatial flow.

Based on calculate BER, FER and/or PER value, can select one or more encoding rates and/or one or more modulation system, make calculate value in corresponding target range, and the data rate of the signal that sent of transmitter 300 is less than or equal to the data designated transmission rate.

By memory 340 multimedia messages of fetching is transferred to channel coding module 302.The multimedia messages of fetching can be used as one or more binary system input blocks, is transferred to channel coding module 302.Each data block is as the input of giving channel coding module, transmits at different time points in mode serially.Each data block comprises a plurality of bits.

Data block after space analysis module 305 will be encoded is resolved, and generates the data block of a plurality of parsings.The data block of the single parsing in the data block of a plurality of parsings comprises at least one part bit in the data block behind this coding.Each resolution data piece that is generated by coded data block comprises and the relevant spatial flow data of corresponding space stream.Each resolution data piece is relevant with one of them spatial flow.

Any one frequency interlacing module 306a ..., 306n can rearrange bit-order in the resolution data piece of being received for corresponding space stream.Each frequency interlacing module 306a ..., 306n can generate the spatial flow piece that interweaves.

Any one mapping block 308a that troops ..., 308n can be with partial bit mapping at least in the spatial flow piece of receiving that interweaves, to generate symbol.Each mapping block 308a that troops ..., 308n use modulation system realizes mapping function separately.

Any one string and modular converter 309a ..., 309n can be to comprise a plurality of parallel bit symbolic representations of exporting bit simultaneously with the Bit String formal transformation of the symbol of generation in the corresponding space stream.As Fig. 2 and shown in Figure 3, by corresponding a plurality of strings and modular converter 309a ..., a plurality of parallel bit symbolic representations that 309n generates are corresponding to multiple source signals 206,208 and 210.

Beam shaping matrix 312 can be carried out beam shaping to generate a plurality of transmission signals based on a plurality of parallel bit symbols of receiving.Processor 342 can be determined the value of each beam shaping factor of each frequency carrier relevant with radio-frequency channel.

Any one IFFT module 310a ..., 310m can become corresponding time domain form signal with the frequency domain form conversion of signals that generates at corresponding transmission signal.Any one inserts GI window module 311a...311m can insert corresponding transmission signal at interval with protection.Any one RFE module 314a...314m can generate the RF signal at corresponding transmitted signals.This RF signal will send via one among the corresponding transmitting antenna 315a...315m by wireless communication medium.

Fig. 4 is the signal Protocol REference Model according to the protocol interaction that is used for MAC layer rate selection of the embodiment of the invention.User platform 402 and management platform 412 have been shown among Fig. 4.Wherein, user platform 402 comprises ULP (upper-layer protocol) 404, MAC layer 406 and PHY layer 408.Management platform 412 comprises rate selection application programming interfaces (API) 414.

Various embodiments of the invention comprise rate selection API 412, and its data rate that receives selection is as input, shown in drawing reference numeral 1.The code that rate selection API 412 comprises can be realized the management platform function associated in the Protocol REference Model of ISO defined (PRM) for example.These functions comprise: set point is with the protocol operation in the control user platform 402, the agreement reception notification incident in the user platform 402, and send response to the one or more agreements in the user platform plate 402.For example, the notice received of the mac-layer protocol 406 in the user platform 402 can make management platform send response to mac-layer protocol 406, PHY layer protocol 408 and/or ULP 404.Based on selected data speed, rate selection API 414 can select MAC layer parameter value, and sends it to MAC layer 406, shown in drawing reference numeral 2.Rate selection API414 can also select PHY layer parameter value, and sends it to PHY layer 408, shown in drawing reference numeral 3.

The selection of PHY layer parameter value and/or MAC layer parameter value should make the transmission data rate of transmitter 300 be less than or equal to selected data speed.

Based on the bit, frame and/or the bag that send, processor 342 can calculate the statistical value of BER, FER and/or PER.For example, the BER statistical value is relevant with PHY layer 408, and the FER statistical value is relevant with MAC layer 406.With calculate the BER statistical value compare with corresponding BER target zone.According to comparative result, PHY layer 408 sends to rate selection API 414 with the report of PHY layer, shown in drawing reference numeral 4.With calculate the FER statistical value compare with corresponding FER target zone.According to comparative result, MAC layer 406 sends to rate selection API 414 with the report of MAC layer, shown in drawing reference numeral 5.

When calculate BER and/or FER statistical value not in corresponding target zone the time, respectively shown in drawing reference numeral 6,7, rate selection API 414 is based on report of PHY layer and the report of MAC layer, revised PHY layer parameter value is sent to PHY layer 408, and/or revised MAC layer parameter value is sent to MAC layer 406.Revised PHY layer parameter value and/or MAC layer parameter value make the transmission data rate of transmitter 300 be less than or equal to selected data speed.

Fig. 5 is the flow chart according to the method step that is used for MAC layer rate selection of the embodiment of the invention.As shown in Figure 5, in the step 502, select data rate.For example, the user-selected number of mobile communication equipment is according to speed.In the step 504, based on selected data rate selection PHY layer parameter value and/or MAC layer parameter value.Processor 342 is realized the selection of PHY layer parameter value and/or MAC layer parameter value.Selected PHY layer parameter value and/or MAC layer parameter value are used for disposing transmitter 300.In the step 506, processor 342 calculates report of PHY layer and/or the report of MAC layer.In the step 508, processor 342 determine to calculate BER, FER and/or the PER value whether in corresponding target zone.If calculate BER, FER and/or PER value all be positioned at corresponding target zone, in the step 510, keep current PHY layer parameter value and/or MAC layer parameter value.Yet, if calculate BER, FER and/or the PER value not in corresponding target zone, in step 512, will select new PHY layer parameter value and/or MAC layer parameter value.Dispose transmitter 300 based on new PHY layer parameter value and/or MAC layer parameter value then.Just execution in step 506 after the step 510 or 512.

Various embodiments of the invention comprise the rate selection algorithm, and the selecting data transmission rate is to reach target BER.In one embodiment of the present of invention, the user can select maximum data transfer rate.Transmitter 300 can use initial PHY layer parameter value and/or MAC layer parameter according to the selected data transmission rate when sending data.When calculate the BER of transmission data during less than target BER, transmitter 300 can reduce message transmission rate subsequently.Transmitter 300 calculates subsequently PHY layer parameter value and/or MAC layer parameter value based on the message transmission rate that reduces.

In an alternative embodiment of the invention, target BER can determine based on ULP (upper-layer protocol).For example, when ULP is TCP, use the first target BER value; When ULP is UDP, use the second target BER value.Among other embodiment of the present invention, PHY layer parameter value and/or MAC layer parameter value can be selected based on the content type (for example, digital video content) of the data that send.

The system of the MAC of being used for rate selection of the present invention comprises at least one processor 342, is used to select MAC layer parameter value and/or PHY layer parameter value, is not more than the message transmission rate of selection with the message transmission rate that keeps at least one to send signal.The error rate of one or more transmission signals will remain in the specified scope according to the SNR of described selection at dynamic change.This error rate can make the error rate, frame error rate and/or Packet Error Ratio.

These one or more processors 342 can be according to sending at least one error rate of calculated signals.This calculate error rate and the error rate scope of appointment compare, revise MAC layer parameter value and/or PHY layer parameter value according to this comparative result again.PHY layer parameter value comprises encoding rate and/or modulation system.The MAC layer parameter comprises contention window value and/or is used to send the number of the transmitting antenna of signal based at least one spatial flow.The antenna selection course can be identified for sending into one or more spatial flows the number of the transmitting antenna of signal.

The present invention can pass through hardware, software, and perhaps soft, combination of hardware realizes.The present invention can realize with centralized system at least one computer system, perhaps be realized with dispersing mode by the different piece in the computer system that is distributed in several interconnection.Anyly can realize that the computer system of said method or miscellaneous equipment all are applicatory.The combination of software and hardware commonly used can be the general-purpose computing system that computer program is installed, and by installing and carry out described program-con-trolled computer system, it is moved by described method.

The present invention can also implement by computer program, and described program comprises whole features that can realize the inventive method, when it is installed in the computer system, by operation, can realize method of the present invention.Computer program in the present specification refers to: one group of any expression formula of instructing that can adopt any program language, code or symbol to write, this instruction group makes system have information processing capability, with direct realization specific function, or after carrying out following one or two step, a) convert other Languages, coding or symbol to; B) reproduce with different forms, realize specific function.

The present invention describes by several specific embodiments, it will be appreciated by those skilled in the art that, without departing from the present invention, can also carry out various conversion and be equal to alternative the present invention.In addition, at particular condition or concrete condition, can make various modifications to the present invention, and not depart from the scope of the present invention.Therefore, the present invention is not limited to disclosed specific embodiment, and should comprise the whole execution modes that fall in the claim scope of the present invention.

Claims (10)

1, a kind of method of handling multimedia messages in communication system is characterized in that described method comprises:

Select MAC layer parameter value and PHY layer parameter value one at least, be not more than the selected data transfer rate with the data transmission rate that keeps at least one transmission signals;

Based on described selection, the error rate of described at least one transmission signals of maintenance is positioned at the scope of appointment at the snr value that changes.

2, the method for handling multimedia messages in communication system according to claim 1 is characterized in that described error rate is as the next one at least: the error rate, frame error rate, Packet Error Ratio.

3, the method for handling multimedia messages in communication system according to claim 1 is characterized in that described method further comprises: calculate at least one error of calculation rate based on described at least one transmission signals.

4, the method for handling multimedia messages in communication system according to claim 3 is characterized in that described method further comprises: more described at least one error of calculation rate and described error rate.

5, the method for handling multimedia messages in communication system according to claim 4 is characterized in that described method further comprises: based on described comparison, revise in the MAC layer parameter value of described selection and the PHY layer parameter value value of one at least.

6, the method for handling multimedia messages in communication system according to claim 1 is characterized in that, described PHY layer parameter value comprises at least as be next: code rate and modulation system.

7, a kind of machine readable code, computer program of storage comprises at least one code segment on it, is used for handling multimedia messages at communication system, described at least one code segment is carried out by machine and is made machine carry out following steps:

Select MAC layer parameter value and PHY layer parameter value one at least, be not more than the selected data transfer rate with the data transmission rate that keeps at least one transmission signals;

Based on described selection, the error rate of described at least one transmission signals of maintenance is positioned at the scope of appointment at the snr value that changes.

8, a kind of system that handles multimedia messages in communication system is characterized in that described system comprises:

At least one processor is used to select MAC layer parameter value and PHY physical layer parameter value one at least, is not more than the selected data transfer rate with the data transmission rate that keeps at least one transmission signals;

Described at least one processor is based on described selection, and the error rate of described at least one transmission signals of maintenance is positioned at the scope of appointment at the snr value that changes.

9, the system that handles multimedia messages in communication system according to claim 8 is characterized in that, described error rate be following at least one: the error rate, Packet Error Ratio, frame error rate.

10, the system that handles multimedia messages in communication system according to claim 8 is characterized in that described at least one processor calculates at least one error of calculation rate based on described at least one transmission signals.

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