CN101714964A - Transmission system, transmission method, sending equipment and receiving equipment for 802.16 - Google Patents
Transmission system, transmission method, sending equipment and receiving equipment for 802.16 Download PDFInfo
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Abstract
The invention relates to a transmission system for 802.16, which comprises sending equipment and receiving equipment, wherein the receiving equipment comprises a channel estimating unit, a modulation mode determining unit and a feedback unit, wherein the channel estimating unit carries out channel estimation according to received data frames; the modulation mode determining unit determines the modulation mode of each subcarrier/subband according to the channel estimation results acquired by the channel estimating unit; and the feedback unit feeds back response frames with the modulation mode of each subcarrier/subband. The sending equipment comprises a modulating unit and an OFDM converting unit, wherein the modulating unit correspondingly modulates each subcarrier/subband according to the response frames fed back by the receiving equipment, and the OFDM converting unit converts signals modulated by the modulating unit into OFDM symbols and sends the OFDM symbols. The invention also discloses sending equipment, receiving equipment and a transmission method for 802.16.
Description
Technical field
The present invention relates to signal transmission technology, particularly be used for 802.16 transmission system and transmission method, and the transmitting apparatus and the receiving equipment that are used for 802.16.
Background technology
802.16 be a kind of wireless metropolitan area network standard that the IEEE tissue proposes, its physical layer has single carrier and two kinds of implementation methods of OFDM (OFDM).When 802.16 existing standards adopt OFDM/OFDMA working method transmission data, it is identical to the modulation system that same user or terminal equipment adopt on each subcarrier/subband, as all adopting BPSK (biphase phase shift keying) modulation or all adopting 16QAM (quadrature amplitude modulation) modulation or the like, this implementation that adopts identical modulation system on each subcarrier/subband is unfavorable for overcoming the frequency selectivity of channel, has reduced the availability of frequency spectrum of system.So-called subband is meant, the sub carrier group of being made up of the subcarrier of adjacent position on the frequency domain.The availability of frequency spectrum of so-called system is meant that the unit spectral bandwidth is the information transmitted amount in the unit interval.
At present,, can improve the availability of frequency spectrum of wireless system though proposed adaptive modulation and coding technology based on OFDM, do not propose as yet a kind of be used for 802.16 based on the transmission technology scheme that subcarrier/subband is modulated respectively.
Summary of the invention
In view of this, the technical problem that the present invention will solve provide a kind of be used for 802.16 based on the transmission system that subcarrier/subband is modulated respectively, to be implemented in 802.16 modulation and transmission signals adaptively.
Described 802.16 the transmission system of being used for comprises transmitting apparatus and receiving equipment, and in certain embodiments, described receiving equipment comprises: the channel estimating unit of carrying out channel estimating according to the Frame that receives; Determine the modulation system determining unit of the modulation system of each subcarrier/subband according to the channel estimation results of described channel estimating unit acquisition; With, feedback has the feedback unit of acknowledgement frame of the modulation system of each subcarrier/subband.Described transmitting apparatus comprises: the modulating unit of correspondingly each subcarrier/subband being modulated according to the acknowledgement frame of receiving equipment feedback; With, the signal transformation that described modulating unit modulation is obtained becomes the OFDM converter unit that sends behind the OFDM symbol.
Another technical problem that the present invention will solve provides a kind of receiving equipment of 802.16 that is used for.
In certain embodiments, described receiving equipment comprises: the channel estimating unit of carrying out channel estimating according to the Frame that receives; Determine the modulation system determining unit of the modulation system of each subcarrier/subband according to the channel estimation results of described channel estimating unit acquisition; With, feedback has the feedback unit of acknowledgement frame of the modulation system of each subcarrier/subband.
Another technical problem that the present invention will solve provides a kind of transmitting apparatus of 802.16 that is used for.
In certain embodiments, described transmitting apparatus comprises: the modulating unit of correspondingly each subcarrier/subband being modulated according to the acknowledgement frame of receiving equipment feedback; With, the signal transformation that described modulating unit modulation is obtained becomes the OFDM converter unit that sends behind the OFDM symbol.
Another technical problem that the present invention will solve provides a kind of transmission method that is used for 802.16 transmitting terminal.In certain embodiments, this method comprises: the acknowledgement frame according to the receiving terminal feedback is correspondingly modulated each subcarrier/subband; The signal transformation that modulation is obtained is orthogonal and sends behind the frequency division multiplex OFDM symbol.
Another technical problem that the present invention will solve provides a kind of transmission method that is used for 802.16 receiving terminal.In certain embodiments, this method comprises: the Frame that sends according to transmitting terminal carries out channel estimating; Determine the modulation system of each subcarrier/subband according to channel estimation results; Feedback has the acknowledgement frame of the modulation system of each subcarrier/subband; The receiving end/sending end OFDM symbols transmitted.
Description of drawings
Fig. 1 is based on the frame structure schematic diagram of 802.16 systems of TDD;
Fig. 2 is the frame structure schematic diagram of bandwidth request mac frame;
Fig. 3 is an embodiment schematic diagram that is used for 802.16 transmission system;
Fig. 4 a, 4b are respectively the schematic diagram of frame structure of acknowledgement frame of subcarrier/subband-modulation system and the schematic diagram of frame head;
Fig. 5 is a structural representation of channel estimating unit;
Fig. 6 a, 6b are respectively the structural representations of the claim frame of subcarrier/subband-modulation system;
Fig. 7, Fig. 8 are respectively two embodiment flow charts that are used for 802.16 transmission method.
Embodiment
Be used for 802.16 Adaptive Modulation transmission plan and be on different sub carrier/subband of OFDM according to the different mining of signal to noise ratio with different signal modulation systems: on the high subcarrier/subband of signal to noise ratio, adopt the modulation of higher-order, adopt the modulation of lower-order on the low subcarrier/subband of signal to noise ratio, the subcarrier/subband low especially for signal to noise ratio then can not transmit data.
When 802.16 adopt the OFDM/OFDMA working method, multiple realization Adaptive Modulation and technical scheme of transmission can be arranged.
A kind of optional scheme is: transmitting terminal sends a Frame that adopts low-order-modulated (all adopting the BPSK modulation as each subcarrier/subband) to receiving terminal, and receiving terminal carries out channel estimating, the modulation system that further determines will to take on each subcarrier/subband again, then sends this information to transmitting terminal by backward channel each subcarrier/subband according to this Frame.
802.16 systems that provide below based on TDD (time division multiplexing) adopt the description that realizes this scheme under the OFDM working method.
Based on the frame structure of 802.16 systems of TDD as shown in Figure 1, wherein, DL and UL represent descending (downlink) and up (uplink) respectively, and its each frame is made of descending sub frame and sub-frame of uplink two parts.Consider base station and certain wireless user, this wireless user be made as user A with being without loss of generality, between downlink communication, at first, in descending sub frame n (DL subframe n), send the Frame of an employing low-order-modulated by the base station to user A; User A carries out channel estimating after receiving this Frame, calculate the snr value of each subcarrier/subband, thus determine each subcarrier/subband the modulation system that should adopt; User A gives the base station at sub-frame of uplink n (UL subframe n) with this feedback information; The base station can utilize this subcarrier/subband-modulation system information and user A to communicate in communication after this.
Be to realize the feedback of subcarrier/subband-modulation system, need a kind of new frame structure that be used to feed back the modulation system information of subcarrier/subband.A kind of optional mode is that the mac frame of existing 802.16 protocol definitions is transformed, and obtains described new frame structure.For example, can transform the bandwidth request mac frame in 802.16 agreements, to obtain transmitting the mac frame of subcarrier/subband-modulation system.
802.16 protocol definition two types mac frame: versatile MAC frame and bandwidth request mac frame, the difference between them indicates by first (HT position) of mac frame.HT=0: versatile MAC frame; HT=1: bandwidth request mac frame.The frame structure of bandwidth request mac frame as shown in Figure 2.Redefine the claim frame that can obtain subcarrier/subband-modulation system and the acknowledgement frame of subcarrier/subband-modulation system by data field to the bandwidth request mac frame.
Fig. 3 shows the embodiment of one 802.16 transmission system.
In transmission system shown in Figure 3, comprise transmitting apparatus 300 and receiving equipment 400.
Wherein, receiving equipment 400 comprises channel estimating unit S41, modulation system determining unit S42 and feedback unit S43.Transmitting apparatus 300 comprises modulating unit S32 and OFDM converter unit S33.
After receiving equipment 400 is received the Frame of transmitting apparatus 300 transmissions, channel estimating unit S41 will carry out channel estimating according to Frame, obtain the signal to noise ratio of each subcarrier/subband.The channel estimation results that modulation system determining unit S42 obtains according to channel estimating unit S41, the signal to noise ratio of each subcarrier/subband is just determined the modulation system of each subcarrier/subband.
Adopt high-order modulating for the high subcarrier of signal to noise ratio/subband, adopt the low-order-modulated mode for the low subcarrier of signal to noise ratio/subband.That is to say that subcarrier/subband that signal to noise ratio is high more should be selected the more modulation system of high-order.If signal to noise ratio is low especially, be lower than a threshold value, then do not use this subcarrier/subband to transmit information, that is to say that modulation system that will this subcarrier/subband is set to invalid modulation system.
After modulation system determining unit S42 had determined the modulation system of each subcarrier/subband, feedback unit S43 can have the acknowledgement frame of the modulation system of each subcarrier/subband to transmitting apparatus 300 feedbacks.
After transmitting apparatus 300 was received acknowledgement frame, the indication of the acknowledgement frame that modulating unit S32 will be fed back according to receiving equipment 400 was correspondingly modulated each subcarrier/subband.Then, OFDM converter unit S33 modulates modulating unit S32 and sends to receiving equipment 400 after the signal transformation that obtains becomes the OFDM symbol.
Wherein, acknowledgement frame can adopt the structure of the bandwidth request mac frame of transformation.The bandwidth request mac frame of described transformation comprises bandwidth request mac frame and a data segment, and wherein, the bandwidth request mac frame is as the frame head of entire frame, and data segment is used to carry modulation system information as frame.
At the bandwidth request mac frame of transforming, can carry the information of the modulation system of each subcarrier/subband by frame.For example, a kind of optional mode is to adopt 4 bits to indicate various modulation systems.Table 1 shows a kind of example that utilizes 4 bits to indicate various modulation systems.
Table 1
| The designation data position | ?0000 | ??0001 | ??0010 | ??0011 | ??0100 |
| Modulation system | ?NULL | ??BPSK | ??QPSK | ??8QAM | ??16QAM |
| The designation data position | ?0101 | ??0110 | ??0111 | ??1000 | |
| Modulation system | ?32QAM | ??64QAM | ??128QAM | ??256QAM |
In the table 1, when modulation system was " NULL ", the modulation system of expression subcarrier/subband was invalid modulation system, that is to say this subcarrier/subband is not modulated.When the modulation system of certain subcarrier/subband is invalid modulation system, mean that this subcarrier/subband will can not be used to transmission information.
In addition, can indicate the length of the designation data position of frame in the BR territory of frame head.The frame structure of the acknowledgement frame of subcarrier/subband-modulation system is shown in Fig. 4 a, and the form of its frame head is shown in Fig. 4 b.The mac frame of transforming among Fig. 4 a is made up of frame head, frame and Cyclic Redundancy Check sign indicating number three parts, and the frame part is made up of subcarrier/subband-modulation system information field and filling (Padding) territory two parts, and Padding does not make it become the integer-bit of 8 bits by zero filling when frame length partly is not the integer-bit of 8 bits.Can utilize the length of length (LENGTH) the territory indication subcarrier/subband-modulation system information field of frame head.
Further, subcarrier/subband-modulation system information field can be made of these three subdomains of Scheme_ID, coded system and modulation system information.
For some receiving equipments, adopt and encode by each subcarrier/data of subband transmission with a kind of coded system, therefore can carry the indication information of digital coding mode by the coded system subdomain.When transmitting apparatus and receiving equipment agreement only adopted a kind of coded system, subcarrier/subband-modulation system information field also can only be made of Scheme_ID and these two subdomains of subcarrier/subband-modulation system information.
The information of subcarrier/subband-modulation system is by one group of data representation, these group data need be represented with a label, this label is exactly Scheme_ID, and be placed in the Scheme_ID subdomain, transmission/receiving equipment can utilize this label to learn the modulation system of the subcarrier/subband of current employing.
Receiving equipment 400 can carry out channel estimating and make immediate acknowledgment according to a Frame.In this case, channel estimating unit S41 will carry out channel estimating according to a Frame, and modulation system determining unit S42 will determine the modulation system of each subcarrier/subband according to the channel estimation results of channel estimating unit S41 acquisition.
Receiving equipment 400 also can carry out channel estimating according to a plurality of Frames, carries out delayed response.In this case, channel estimating unit S41 will carry out channel estimating according to a plurality of Frames, and modulation system determining unit S42 will determine whether channel is stable according to the channel estimation results of channel estimating unit S41 acquisition; When channel is stablized, determine the modulation system of each subcarrier/subband again.Adopt the processing mode of this delayed response, can obtain the numerical value of subcarrier/subband-modulation system more accurately on the one hand, also can avoid the incorrect use of this physical layer working method of subcarrier/subband-modulation system on the other hand.
A kind ofly optionally judge whether stable manner is subcarrier/subband, suppose that receiving equipment 400 receives N Frame altogether, these Frames all adopt K subcarrier/subband to send data to receiving equipment, for k (k=1,2, ..., K) individual subcarrier/subband, channel estimating unit S41 is respectively C according to the channel coefficients estimated value that the different pieces of information frame calculates each subcarrier/subband
k(1), C
k(2) ..., C
k(N).Modulation system determining unit S42 will be by calculating
Obtain the average C of the channel coefficients estimated value of each subcarrier/subband
kAnd by calculating
Obtain the variance Var (C of the channel coefficients estimated value of each subcarrier/subband
k).Variance Var (C with the channel coefficients estimated value of each subcarrier/subband
k) compare with threshold value Δ C given in advance, if Var (C
k) be less than or equal to Δ C, then k subcarrier/subband is stable; If Var (C
k) greater than Δ C, then k subcarrier/subband is unsettled.
Quantity β when stable subcarrier/subband
KWhen being equal to or greater than the threshold value of setting, promptly the decidable channel is stable; Otherwise channel is unsettled.When channel is stablized, the average C of the channel coefficients estimated value that modulation system determining unit S42 can each subcarrier/subband
kDetermine the modulation system of each subcarrier/subband.When channel was unstable, a kind of optional mode was that modulation system determining unit S42 continues the channel estimation results of N Frame of next group is judged, and is stable until channel.
Another kind optionally judges whether stable manner is subcarrier/subband, suppose that receiving equipment 400 receives N Frame altogether, these Frames all adopt K subcarrier/subband to send data to receiving equipment, for k (k=1,2 ..., K) individual subcarrier/subband, receiving equipment carries out channel estimating respectively, and determines modulation system according to this N Frame, establishes the bit number that each symbol of determined modulation system can transmit and is respectively B
k(1), B
k(2) ..., B
k(N), as: the bit number that each symbol can transmit under the BPSK modulation system is 1, and the bit number that each symbol can transmit under the 16QAM modulation system is 4, or the like.Modulation system determining unit S42 calculates the difference D of its maximum and minimum value
k: D
k=max{B
k(n), n=1,2 ..., N}-min{B
k(n), n=1,2 ..., N}.With D
kCompare with threshold value Δ B given in advance, if D
kBe less than or equal to Δ B, then k subcarrier/subband is stable; If D
kGreater than Δ B, then k subcarrier/subband is unsettled.
Quantity β when stable subcarrier/subband
KWhen being equal to or greater than the threshold value of setting, promptly the decidable channel is stable; Otherwise channel is unsettled.When channel is stablized, the D that modulation system determining unit S42 can each subcarrier/subband
kDetermine the modulation system of each subcarrier/subband.When channel was unstable, a kind of optional mode was that modulation system determining unit S42 continues the channel estimation results of N Frame of next group is judged, and is stable until channel.
Channel estimating unit S41 is when carrying out channel estimating, and a kind of optional mode is, to the information sequence that obtains after the decoding through CRC check for after correct, it encoded again and modulate, be used for more precise channels as the training sequence of new lengthening and estimate.In this case, channel estimating unit S41 is that unit makes channel estimating to each subcarrier/subband of OFDM with the OFDM symbol.
The OFDM symbolic number of supposing to be used for channel estimating is K (at the physical frame that receiving equipment receives, if last OFDM symbol is not sent out data and fills up, it can be not used in anti-body formula channel estimating).
For arbitrary OFDM symbol k (k=1,2 ..., K), the correlation of the subcarrier/subband symbol sebolic addressing after its subcarrier that receives/subband symbol sebolic addressing and the coded modulation is seen Fig. 6.Wherein, information sequence is exactly the mac frame that system is transmitted by the OFDM data symbol, and its correctness can be verified by CRC check; Equalizer comes work according to the channel coefficients that channel estimating provides; The demodulating and decoding device is to doing the operation of demodulation, decoding etc. through balanced ofdm signal, it is by section constructions such as demodulator, deinterleaver, decoder, descrambler; Coding demodulator is then pressed the operation of the regulation of 802.16 agreements to information sequence work coding, modulation, re-constructs the symbol sebolic addressing of transmission, and it is made of institutes such as scrambler, encoder, interleaver, modulators.
Another kind of optionally Adaptive Modulation and technical scheme of transmission are: transmitting terminal sends a particular frame to receiving terminal, receiving terminal according to this particular frame that receives carry out channel estimating, again determine on each subcarrier/subband modulation system, then it is fed back to transmitting terminal.Transmitting terminal obtain on each subcarrier/subband after the information of the modulation system that should adopt, will correspondingly modulate each subcarrier/subband by the feedback of receiving terminal, and further be transformed into ofdm signal and transmit.The advantage of this scheme is, the particular frame that transmitting terminal sends can be received by all receiving terminals, therefore, need only once transmit, and the subcarrier/subband between current transmitting terminal and all receiving terminals-modulation system information can be determined.This scheme is specially adapted to send the down link of data by the base station to the wireless user, under the OFDMA working method, then can be thus to different user allocation of subcarriers/subband more reasonably.
Consider base station and certain wireless user, this wireless user is made as user A with being without loss of generality, between downlink communication, at first, in descending sub frame n, send a claim frame that adopts low-order-modulated by the base station, notify user A to feed back the information of subcarrier/subband-modulation system to it by some flag bits to user A; User A carries out channel estimating after receiving this claim frame, the gain of calculating each subcarrier/subband further obtains the snr value of each subcarrier/subband, and determine each subcarrier/subband the modulation system that should adopt; User A gives the base station at sub-frame of uplink n with this feedback information; The base station can utilize this subcarrier/subband-modulation system information and user A to communicate in communication after this.
Still be example with 802.16 the transmission system of being used for shown in Figure 3, transmitting apparatus 300 sends no longer is common Frame but is exclusively used in the claim frame of the modulation system of request receiving equipment 400 each subcarrier/subband of feedback.After receiving equipment 400 is received claim frame, channel estimating unit S41 will carry out channel estimating according to claim frame, obtain the signal to noise ratio of each subcarrier/subband.The channel estimation results that modulation system determining unit S42 obtains according to channel estimating unit S41, the signal to noise ratio of each subcarrier/subband is just determined the modulation system of each subcarrier/subband.
After modulation system determining unit S42 had determined the modulation system of each subcarrier/subband, feedback unit S43 can have the acknowledgement frame of the modulation system of each subcarrier/subband to transmitting apparatus 300 feedbacks.
After transmitting apparatus was received acknowledgement frame, the indication of the acknowledgement frame that modulating unit S32 will be fed back according to receiving equipment 400 was correspondingly modulated each subcarrier/subband.Then, OFDM converter unit S33 modulates modulating unit S32 and sends to receiving equipment 400 after the signal transformation that obtains becomes the OFDM symbol.
The claim frame of subcarrier/subband-modulation system can adopt the mode identical with the acknowledgement frame of subcarrier/subband-modulation system to construct, and promptly obtains by the data field in the bandwidth request mac frame is redefined.In 802.16 existing agreements, 000 and 001 two numerical value has only been used in the Type territory of bandwidth request mac frame, and Type=000 represents bandwidth increments, and Type=000 represents aggregate bandwidth.Other 6 numerical value are as retention.Claim frame and the acknowledgement frame that can represent subcarrier/subband-modulation system with two numerical value in the Type territory, such as, the claim frame that can represent subcarrier/subband-modulation system with Type=010 is represented the acknowledgement frame of subcarrier/subband-modulation system with Type=011.Under the situation of subcarrier/subband-modulation system information request frame, the BR territory can be made as the reservation territory, perhaps get rid of the shared bit in BR territory, the claim frame of the subcarrier/subband that obtains thus-modulation system is shown in Fig. 6 a or 6b.
When sending claim frame, a kind of reasonable mode is to adopt the modulation system modulation request frame of low order, for example, can adopt BPSK mode modulation request frame.
In 802.16 systems, can be accomplished in several ways the application of subcarrier/subband-modulation system.Can adopt the mode of clean culture to send the claim frame of subcarrier/subband-modulation system, perhaps also can adopt broadcasting or multicast mode to send the claim frame of subcarrier/subband-modulation system, specifically adopt which kind of mode to be determined on a case-by-case basis.
A kind of optional implementation is, the base station utilizes the chance that sends broadcast message to send the claim frame of the subcarrier/subband-modulation system of broadcast mode to each user terminal, and the CID in this moment this frame is made as broadcasting CID; After this, each user terminal is made feedback with the acknowledgement frame of subcarrier/subband-modulation system in uplink communication.
Another kind of optionally implementation is, the base station utilizes the chance that sends broadcast message to organize the claim frame of the subcarrier/subband-modulation system that sends the multicast mode to a user, CID in this frame is made as multicast CID at this moment, after this, the equipment in user's group is made feedback with the acknowledgement frame of subcarrier/subband-modulation system in uplink communication.
Another kind of optionally implementation is that transmitting apparatus (base station or user) sends the claim frame of subcarrier/subband-modulation system to receiving equipment (user or base station); After this, receiving equipment is made feedback with the acknowledgement frame of subcarrier/subband-modulation system.
Fig. 7 shows a kind of transmission method of 802.16 that is used for, and this method is used in transmitting terminal.
Fig. 8 shows another kind and is used for 802.16 transmission method, and this method is used in receiving terminal.
By as can be known to the description of transmission system, can utilize channel estimation results to a Frame, determine the modulation system of each subcarrier/subband; Also can utilize the channel estimation results of a plurality of Frames is judged channel status, and when channel is stablized, determine the modulation system of each subcarrier/subband.
Wherein, can utilize the channel estimation results of a plurality of Frames to determine stable subcarrier/subband and quantity thereof; Quantity β when stable subcarrier/subband
KWhen being equal to or greater than β, channel is stable; Quantity β when stable subcarrier/subband
KDuring less than β, channel is unsettled.Wherein, can utilize the channel estimation results of a plurality of Frames to calculate the variance Var (C of the channel coefficients estimated value of each subcarrier/subband
k), variance Var (C
k) subcarrier/subband of being less than or equal to Δ C is stable subcarrier/subband.
When channel is stablized, the average C of channel coefficients estimated value that can each subcarrier/subband
kDetermine the modulation system of each subcarrier/subband.
The present invention also provides a kind of integrated circuit, is used to realize described device of above-mentioned arbitrary embodiment or method.The present invention also provides a kind of computer-readable medium, stores the program that is used to realize the described method of above-mentioned arbitrary embodiment.
Those skilled in the art can understand, various exemplary method step of describing in conjunction with the disclosed embodiments and device unit all can electronic hardware here, software or the combination of the two realize.In order to be clearly shown that the interchangeability between the hardware and software, more than various exemplary steps and unit are all carried out generally description with its functional form.This functional be to realize or realize depending on the design constraint that specific application and whole system are realized with software with hardware.Those skilled in the art can be at each specific application, realize in many ways described functional, but the result of this realization should not be construed as and on the contrary deviates from scope of the present invention.
Utilize general processor, digital signal processor (DSP), application-specific integrated circuit (ASIC) (ASIC), field programmable gate array (FPGA) or other programmable logical device, discrete gate or transistor logic, discrete hardware components or the combination in any among them, can realize or carry out the various exemplary unit of describing in conjunction with embodiment disclosed herein.General processor may be a microprocessor, but in another kind of situation, this processor may be processor, controller, microcontroller or the state machine of any routine.Processor also may be implemented as the combination of computing equipment, for example, and the combination of DSP and microprocessor, a plurality of microprocessor, one or more microprocessor or any other this kind structure in conjunction with the DSP core.
In conjunction with the step of the described method of above-mentioned disclosed embodiment can directly be presented as hardware, the software module carried out by processor or the combination of these two.Software module may be present in the storage media of RAM memory, flash memory, ROM memory, eprom memory, eeprom memory, register, hard disk, mobile disk, CD-ROM or any other form well known in the art.The coupling of a kind of exemplary storage medium and processor, thus make processor can be from this storage media read message, and can be to this storage media write information.In replacing example, storage media is the part of processor.Processor and storage media may be present among the ASIC.This ASIC may be present in the subscriber station.Replace in the example at one, the discrete assembly that processor and storage media can be used as in the subscriber station exists.
According to described disclosed embodiment, can be so that those skilled in the art can realize or use the present invention.To those skilled in the art, the various modifications of these embodiment are conspicuous, and the general principles of definition here also can be applied to other embodiment on the basis that does not depart from the scope of the present invention with purport.Above-described embodiment only is preferred embodiment of the present invention, and is in order to restriction the present invention, within the spirit and principles in the present invention not all, any modification of being done, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (33)
1. a transmission system is used for 802.16, comprises receiving equipment and transmitting apparatus, it is characterized in that, described receiving equipment comprises:
Channel estimating unit is used for carrying out channel estimating according to the Frame that receives;
The modulation system determining unit is used for determining according to the channel estimation results that described channel estimating unit obtains the modulation system of each subcarrier/subband; With
Feedback unit is used to feed back the acknowledgement frame of the modulation system that has each subcarrier/subband; Described transmitting apparatus comprises:
Modulating unit is used for correspondingly each subcarrier/subband being modulated according to the described acknowledgement frame of receiving equipment feedback; With
The OFDM converter unit sends after being used for the signal transformation that the modulation of described modulating unit obtains become the OFDM symbol.
2. transmission system as claimed in claim 1 is characterized in that, described acknowledgement frame adopts the structure of the bandwidth request mac frame of transforming.
3. transmission system as claimed in claim 2 is characterized in that, the bandwidth request mac frame of described transformation comprises bandwidth request mac frame and a data segment;
Wherein, the bandwidth request mac frame is as the frame head of entire frame, and described data segment is as frame.
4. transmission system as claimed in claim 3 is characterized in that, the modulation system that acknowledgement frame carries subcarrier/subband by frame is carried the descriptor of subcarrier/subband and modulation system thereof by frame head.
5. transmission system as claimed in claim 4 is characterized in that, by the modulation system of 4 bit indication subcarrier/subbands.
6. transmission system as claimed in claim 1, it is characterized in that, channel estimating unit is carried out channel estimating according to a Frame, and the modulation system determining unit is determined the modulation system of each subcarrier/subband according to the channel estimation results that channel estimating unit obtains.
7. transmission system as claimed in claim 1, it is characterized in that, channel estimating unit is carried out channel estimating according to a plurality of Frames, the modulation system determining unit is judged channel status according to the channel estimation results that channel estimating unit obtains, and determines the modulation system of each subcarrier/subband when channel is stablized.
8. transmission system as claimed in claim 7 is characterized in that, utilizes the channel estimation results of a plurality of Frames to determine stable subcarrier/subband and quantity thereof;
When the quantity of stable subcarrier/subband was equal to or greater than first threshold value, channel was stable;
When the quantity of stable subcarrier/subband during less than first threshold value, channel is unsettled.
9. transmission system as claimed in claim 8, it is characterized in that, utilize the channel estimation results of a plurality of Frames to calculate the variance of the channel coefficients estimated value of each subcarrier/subband, subcarrier/subband that variance is less than or equal to second threshold value is stable subcarrier/subband.
10. transmission system as claimed in claim 9 is characterized in that, the modulation system determining unit is determined the modulation system of each subcarrier/subband with the average of the channel coefficients estimated value of each subcarrier/subband.
11., it is characterized in that described Frame is to be exclusively used in the claim frame that the request receiving equipment feeds back the modulation system of each subcarrier/subband as each described transmission system of claim 1 to 10.
12. transmission system as claimed in claim 11 is characterized in that, the described request frame adopts the structure of bandwidth request mac frame.
13. transmission system as claimed in claim 12 is characterized in that, different particular values is set to distinguish described claim frame and acknowledgement frame in the Type territory of bandwidth request mac frame.
14. transmission system as claimed in claim 13 is characterized in that, is set to keep the shared bit number in territory or deletion BR territory in claim frame BR territory.
15. transmission system as claimed in claim 11 is characterized in that, the described request frame is broadcasted transmission, multicast sends or clean culture sends.
16. transmission system as claimed in claim 11 is characterized in that, the described request frame is by low-order-modulated.
17. transmission system as claimed in claim 16 is characterized in that, the modulation system of described request frame is BPSK.
18. a transmitting apparatus is used for 802.16, it is characterized in that, comprises as each described modulating unit of claim 1 to 17 and OFDM converter unit.
19. a receiving equipment is used for 802.16, it is characterized in that, comprises as each described channel estimating unit of claim 1 to 17, modulation system determining unit and feedback unit.
20. a transmission method is used for 802.16, is used in receiving terminal, it is characterized in that, comprising:
The Frame that sends according to transmitting terminal carries out channel estimating;
Determine the modulation system of each subcarrier/subband according to channel estimation results;
Feedback has the acknowledgement frame of the modulation system of each subcarrier/subband;
The orthogonal frequency division multiplex OFDM symbol of receiving end/sending end emission.
21. transmission method as claimed in claim 20 is characterized in that, described acknowledgement frame adopts the structure of the bandwidth request mac frame of transforming.
22. transmission method as claimed in claim 21 is characterized in that, the modulation system that acknowledgement frame carries subcarrier/subband by frame is carried the descriptor of subcarrier/subband and modulation system thereof by frame head.
23. transmission method as claimed in claim 20 is characterized in that, carries out channel estimating according to a Frame, determines the modulation system of each subcarrier/subband according to the channel estimation results that obtains.
24. transmission method as claimed in claim 20 is characterized in that, carries out channel estimating according to a plurality of Frames, judges channel status according to the channel estimation results that obtains, and determines the modulation system of each subcarrier/subband when channel is stablized.
25. transmission method as claimed in claim 24 is characterized in that, utilizes the channel estimation results of a plurality of Frames to determine stable subcarrier/subband and quantity thereof;
When the quantity of stable subcarrier/subband was equal to or greater than first threshold value, channel was stable;
When the quantity of stable subcarrier/subband during less than first threshold value, channel is unsettled.
26. transmission method as claimed in claim 25, it is characterized in that, utilize the channel estimation results of a plurality of Frames to calculate the variance of the channel coefficients estimated value of each subcarrier/subband, subcarrier/subband that variance is less than or equal to second threshold value is stable subcarrier/subband.
27. transmission method as claimed in claim 26 is characterized in that, determines the modulation system of each subcarrier/subband with the average of the channel coefficients estimated value of each subcarrier/subband.
28., it is characterized in that described Frame is to be exclusively used in the claim frame that the request receiving equipment feeds back the modulation system of each subcarrier/subband as each described transmission method of claim 20 to 27.
29. transmission method as claimed in claim 28 is characterized in that, the described request frame adopts the structure of bandwidth request mac frame.
30. transmission method as claimed in claim 28 is characterized in that, the described request frame is broadcasted transmission, multicast sends or clean culture sends.
31. transmission system as claimed in claim 28 is characterized in that, the described request frame is by low-order-modulated.
32. transmission system as claimed in claim 31 is characterized in that, the modulation system of described request frame is BPSK.
33. a transmission method is used for 802.16, is used in transmitting terminal, it is characterized in that, comprising:
Acknowledgement frame according to the receiving terminal feedback is correspondingly modulated each subcarrier/subband;
The signal transformation that modulation is obtained is orthogonal and sends behind the frequency division multiplex OFDM symbol.
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| Application Number | Priority Date | Filing Date | Title |
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| CN200810225912A CN101714964A (en) | 2008-11-06 | 2008-11-06 | Transmission system, transmission method, sending equipment and receiving equipment for 802.16 |
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| Application Number | Priority Date | Filing Date | Title |
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| CN200810225912A CN101714964A (en) | 2008-11-06 | 2008-11-06 | Transmission system, transmission method, sending equipment and receiving equipment for 802.16 |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013139087A1 (en) * | 2012-03-22 | 2013-09-26 | 中兴通讯股份有限公司 | Channel measurement feedback indicating method and sending station |
| CN103444249A (en) * | 2011-03-31 | 2013-12-11 | 北京新岸线移动多媒体技术有限公司 | Resource request method, station, and central access point |
| CN104079515A (en) * | 2013-03-29 | 2014-10-01 | 华为技术有限公司 | Adjustment method of modulation mode and modems |
| CN105721151A (en) * | 2016-04-06 | 2016-06-29 | 北京瀚诺半导体科技有限公司 | Information encryption method in OFDM communication system |
-
2008
- 2008-11-06 CN CN200810225912A patent/CN101714964A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103444249A (en) * | 2011-03-31 | 2013-12-11 | 北京新岸线移动多媒体技术有限公司 | Resource request method, station, and central access point |
| WO2013139087A1 (en) * | 2012-03-22 | 2013-09-26 | 中兴通讯股份有限公司 | Channel measurement feedback indicating method and sending station |
| US9930552B2 (en) | 2012-03-22 | 2018-03-27 | Zte Corporation | Method for indicating channel measurement feedback and sending station |
| CN104079515A (en) * | 2013-03-29 | 2014-10-01 | 华为技术有限公司 | Adjustment method of modulation mode and modems |
| CN105721151A (en) * | 2016-04-06 | 2016-06-29 | 北京瀚诺半导体科技有限公司 | Information encryption method in OFDM communication system |
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