CN103457895B - A kind of OFDM transmission method, device and Transmission system - Google Patents
A kind of OFDM transmission method, device and Transmission system Download PDFInfo
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- CN103457895B CN103457895B CN201210590517.1A CN201210590517A CN103457895B CN 103457895 B CN103457895 B CN 103457895B CN 201210590517 A CN201210590517 A CN 201210590517A CN 103457895 B CN103457895 B CN 103457895B
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Abstract
The invention discloses a kind of OFDM transmission methods, devices and systems, the method for being applied to transmitting terminal includes：Obtain the first time-domain OFDM symbol；Using preceding L data in the first time-domain OFDM symbol as first time-domain OFDM symbol cyclic suffix data buffer storage, the L is the length value of the cyclic suffix, and sends first time-domain OFDM symbol；After first time-domain OFDM symbol is sent, the cyclic suffix data of caching are sent, form the time domain orthogonal frequency division multiplexing symbol CPO OFDM with cyclic suffix.By technical scheme, only need to be cached after the time-domain OFDM symbol is formed the data of wherein cyclic suffix, the data bulk of caching is needed so as to greatly reduce, and then RAM resources can be saved, and simplify generation OFMD time-domain symbols handling process complexity, improve system effectiveness.
Description
Technical field
The present invention relates to the communications field, more particularly to a kind of OFDM transmission methods, devices and systems.
Background technology
At present, in order to improve the frequency efficiency of communication, usually using orthogonal frequency division multiplexi（OFDM）To realize letter
Number transmission.OFDM technology is a kind of multi-carrier communication technology, can be by the multiple parallel positive jiao zi of minimum frequency space
Carrier-wave transmission information realizes frequency efficiency higher.
During OFDM transmission, the frequency-domain OFDM symbol that transmitting terminal is transmitted according to required for becomes by inverse discrete fourier
Change（IDFT）Time-domain OFDM symbol is obtained, then each time-domain OFDM symbol is sent out successively according to respective time domain, from
And ofdm signal is formed, and receiving terminal is when ofdm signal is received, then each time-domain OFDM symbol therein is carried out discrete
Fourier transformation（DFT）, so as to obtain frequency-domain OFDM symbol.And in the transmitting procedure of ofdm signal, in order to avoid multipath is imitated
Should cause interfere between each time-domain OFDM symbol and be protected, it is necessary to be inserted in the middle of each time-domain OFDM symbol of ofdm signal
Shield interval.
There are four kinds of insertion protection intervals to form the mode of ofdm signal in the prior art, Cyclic Prefix, zero number are used respectively
According to, pseudo-random sequence and frequency pilot sign as protection interval.Wherein, the ofdm signal of Cyclic Prefix is most commonly used at present
（CP-OFDM）.Each time domain CP-OFDM symbols are by will be last in its corresponding time-domain OFDM symbol in CP-OFDM signals
One piece of data copies to the protection interval before the time-domain OFDM symbol and is formed, as shown in figure 1, wherein, time domain OFDM symbol
Number length it is more long, its replicate final stage data length it is more long.
Data in time-domain OFDM symbol are inserted into protection interval before the symbol because CP-OFDM signals are used,
So in the signal transmission process of each CP-OFDM symbol be actually first by formed through inverse discrete Fourier transform when
Final stage data is activation in the OFDM symbol of domain, then the time-domain OFDM symbol is entirely sent.It is that insertion is protected due to what is first sent
The data at interval are protected, so the delay that time-domain OFDM symbol will be in generation time between formation and transmission, so, through inverse
Discrete Fourier transform is obtained after time-domain OFDM symbol, it is necessary to all cache whole time-domain OFDM symbol, could be when sending
Form CP-FDMA symbols.And because whole time-domain OFDM symbol is required for caching, so being accomplished by taking more RAM storages
Space, consumes more RAM resources.
The content of the invention
The problem to be solved in the present invention is to provide a kind of OFDM transmission methods, devices and systems, to overcome prior art to lead to
Cross and the more RAM that comes to be formed to take caused by protection interval that data in time-domain OFDM symbol insert the symbol is stored empty
Between, consume the defect of more RAM resources.
To reach above-mentioned purpose, the invention provides a kind of OFDM transmission method, transmitting terminal is applied to, methods described includes
Following steps：
Obtain the first time-domain OFDM symbol；
Preceding L data in first time-domain OFDM symbol are delayed as the cyclic suffix data of first time-domain OFDM symbol
Deposit, the L is the length value of the cyclic suffix, and send first time-domain OFDM symbol；
After first time-domain OFDM symbol is sent, the cyclic suffix data of caching are sent, formed to carry and followed
The time domain orthogonal frequency division multiplexing symbol CPO-OFDM of ring suffix.
Preferably, before the first time-domain OFDM symbol of the acquisition, also include：
Inverse discrete Fourier transform is carried out to the first frequency-domain OFDM symbol, first time-domain OFDM symbol is obtained.
Present invention also offers a kind of OFDM transmission method, receiving terminal is applied to, the described method comprises the following steps：
Receive time domain CPO-OFDM symbols；The time domain CPO-OFDM symbols are the side described in the foregoing any one of transmitting terminal
The signal that method sends；
Preceding L data in the time domain CPO-OFDM symbols are deleted, the second time-domain OFDM symbol is obtained.
Preferably, it is described obtain the second time-domain OFDM symbol after, also include：
Discrete Fourier transform is carried out to second time-domain OFDM symbol, the second frequency-domain OFDM symbol is obtained；
According to the position of each data in the second frequency-domain OFDM symbol, to each subcarrier in the second frequency-domain OFDM symbol
Data carry out corresponding phase compensation, to obtain the frequency domain data that transmitting terminal is sent by the time domain CPO-OFDM symbols.
Preferably, it is described obtain the second time-domain OFDM symbol after, also include：
Discrete Fourier transform is carried out to second time-domain OFDM symbol, the second frequency-domain OFDM symbol is obtained；
It is each subcarrier in the second frequency-domain OFDM symbol according to the position of each data in the second frequency-domain OFDM symbol
Data set corresponding phase offset factor；
Each subcarrier data in the second frequency-domain OFDM symbol is sampled using corresponding phase offset factor
Frequency deviation is corrected, to obtain the frequency domain data that transmitting terminal is sent by the time domain CPO-OFDM symbols.
Present invention also offers a kind of OFDM transmission device, transmitting terminal is applied to, including：
OFDM acquisition modules, for obtaining the first time-domain OFDM symbol；
Cyclic suffix cache module, for using preceding L data in the first time-domain OFDM symbol as first time domain
The cyclic suffix data buffer storage of OFDM symbol；The L is the length value of the cyclic suffix；
OFDM sending modules, for sending first time-domain OFDM symbol；
Cyclic suffix sending module, follows for after first time-domain OFDM symbol is sent, sending the described of caching
Ring suffix data, forms the time domain orthogonal frequency division multiplexing symbol CPO-OFDM with cyclic suffix.
Preferably, also include：
Inverse transform module, for carrying out inverse discrete Fourier transform to the first frequency-domain OFDM symbol, when obtaining described first
Domain OFDM symbol.
Present invention also offers a kind of OFDM transmission device, receiving terminal is applied to, including：
Symbol receiver module, for receiving time domain CPO-OFDM symbols；The time domain CPO-OFDM symbols are adopted for transmitting terminal
With the signal that end device sends that sends described in foregoing any one；
Removing module, for preceding L data in the time domain CPO-OFDM symbols to be deleted, obtains the second time domain OFDM symbol
Number.
Preferably, also include：
Conversion module, for carrying out discrete Fourier transform to second time-domain OFDM symbol, obtains the second frequency domain
OFDM symbol；
Subcarrier compensating module, for the position according to each data in the second frequency-domain OFDM symbol, to the described second frequency
Each subcarrier data carries out corresponding phase compensation in the OFDM symbol of domain, to obtain transmitting terminal by the time domain CPO-OFDM
The frequency domain data that symbol sends.
Preferably, also include：
Conversion module, for carrying out discrete Fourier transform to second time-domain OFDM symbol, obtains the second frequency domain
OFDM symbol；
Displacement factor setup module, is described second for the position according to each data in the second frequency-domain OFDM symbol
Each subcarrier data sets corresponding phase offset factor in frequency-domain OFDM symbol；
Frequency deviation rectification module, for using corresponding phase offset factor to each son in the second frequency-domain OFDM symbol
Carrier data carries out sampling frequency offset correction, to obtain the frequency domain number that transmitting terminal is sent by the time domain CPO-OFDM symbols
According to.
Present invention also offers a kind of OFDM transmission system, including：Transmission end device described in foregoing any one, and,
Receiving end device described in foregoing any one.
Compared with prior art, the present invention has advantages below：
Technical scheme, uses as the protection interval of each time-domain OFDM symbol addition cyclic suffix carrys out shape
Into time domain OFDM signal, after the first time-domain OFDM symbol is read, the preceding L numbers as its cyclic suffix in the symbol are cached
According to, and first entirely send the OFDM symbol, followed by the cyclic suffix sent in caching, formed with cyclic suffix with this
Time domain orthogonal frequency division multiplexing symbol（Time domain CPO-OFDM symbols）.By technical scheme, due to using in time domain
Its protection interval is inserted after OFDM symbol, so after forming the time-domain OFDM symbol, due to only as protection interval
Circulation follow-up data needs to wait whole time-domain OFDM symbol to be sent and could send, so only needing in the formation time domain
The data of wherein cyclic suffix are cached after OFDM symbol, it is possible to directly send the symbol, need to delay so as to greatly reduce
The data bulk deposited, and then the RAM memory spaces for needing to take are reduced, so as to reduce the consumption of RAM resources.
Brief description of the drawings
Fig. 1 is the formation schematic diagram of existing CP-OFDM signals；
Fig. 2 is the flow chart of the embodiment 1 of OFDM transmission method of the present invention；
Fig. 3 is the schematic diagram run quickly and invent the CPO-OFDM signals for being formed；
Fig. 4 is the flow chart of the embodiment 2 of OFDM transmission method of the present invention；
Fig. 5 is the flow chart of the frequency domain data implementation method 1 of acquisition transmitting terminal transmission in the inventive method embodiment 2；
Fig. 6 is the flow chart of the frequency domain data implementation method 2 of acquisition transmitting terminal transmission in the inventive method embodiment 2；
Fig. 7 is the structure chart of OFDM transmission device embodiment 1 of the present invention；
Fig. 8 is the structure chart of OFDM transmission device embodiment 2 of the present invention；
Fig. 9 is the structure chart of OFDM transmission device embodiment 3 of the present invention；
Figure 10 is the structure chart of OFDM transmission device embodiment 4 of the present invention；
Figure 11 is the structure chart of OFDM transmission device embodiment 5 of the present invention；
Figure 12 is the structure chart of OFDM transmission system embodiment 1 of the present invention.
Specific embodiment
We will be described in detail with reference to accompanying drawing to preferred embodiment of the invention below.Firstly it is pointed out that
The implication of term, words and the claim used in the present invention can not be only limited to its literal and common implication and go to understand,
The implication and concept for also including and then being consistent with technology of the invention, because we are used as inventor, suitably be given
The definition of term, so that the invention to us carries out most appropriate description.Therefore, the configuration for being given in this explanation and accompanying drawing, only
It is first-selected embodiment of the invention, rather than enumerating all technical characteristics of the invention.We are it would be recognized that also various
The equivalent scheme or modification that our schemes can be replaced of various kinds.
In present invention may apply to various ofdm communication systems, it is particularly suited for optical fiber ofdm communication system
Basic thought of the invention is：The protection interval of cyclic suffix is added in each time-domain OFDM symbol, will each
The last period data duplication in time-domain OFDM symbol forms time domain CPO- to sending to form protection interval behind the symbol
OFDM symbol.Because the transmission process for data in time-domain OFDM symbol is first to send whole symbol to retransmit circulation therein
Suffix data, so, the symbol only has cyclic suffix data therein to also need to be sent out when the symbol after formation during transmission
Send and sent again after finishing, therefore, just only needed to the cyclic suffix data buffer storage in the time-domain OFDM symbol when sending,
And no longer need all to cache whole time-domain OFDM symbol, such that it is able to save the memory space of caching RAM.
Below in conjunction with accompanying drawing, the specific of OFDM transmission methods, devices and systems of the present invention is described in detail with embodiment
Implementation.
Referring to Fig. 2, the flow chart of the embodiment 1 of OFDM transmission method of the present invention is shown, the present embodiment is applied to send
End, can include：
Step 201, the first time-domain OFDM symbol of acquisition.
Wherein, the first time-domain OFDM symbol is established time-domain OFDM symbol.Therefore, before step 101 execution, this
Embodiment can also include：Inverse discrete Fourier transform is carried out to the first frequency-domain OFDM symbol, first time domain OFDM is obtained
Symbol.
It should be noted that in ofdm communication system, the data of required transmission can be constituted in the form of frequency domain data
Frequency-domain OFDM symbol one by one.During above-mentioned inverse discrete Fourier transform, actually in the first frequency-domain OFDM symbol
Each frequency domain data carries out inverse discrete Fourier transform.
It is understood that due to only caching a part of number in the first time-domain OFDM symbol in the present embodiment subsequent step
According to, therefore, it is to reduce the spatial cache for needing to take as far as possible, the first time-domain OFDM symbol acquired in the present embodiment is preferably
The symbol for just having been formed through inverse discrete Fourier transform.
Step 202, using preceding L data in the first time-domain OFDM symbol as after the circulation of first time-domain OFDM symbol
Sew data buffer storage, the L is the length value of the cyclic suffix, and send first time-domain OFDM symbol.
Wherein, the numerical value of L can be set according to the length of the first time-domain OFDM symbol and channel delay spread characteristic.It is logical
In the case of often, the length of the first time-domain OFDM symbol is more long or channel delay spread is bigger, and the numerical value of set L is bigger.
In addition, the data in the first time-domain OFDM symbol are present in the form of time domain data, then need to account for during each data is activation
Use regular hour length.
It should be noted that caching cyclic suffix is usually while carrying out with the first time-domain OFDM symbol of transmission.For
For one time-domain OFDM symbol, the data obtained by inverse discrete Fourier transform can be obtain together, or one
A part part is obtained in batches, wherein can be a data, or multiple data per batch data.So, to data
The first time-domain OFDM symbol for being formed in batches, for the every batch data in first time-domain OFDM symbol after formation, can
First to judge whether the batch data is the data of the cyclic suffix for needing caching, if it is, just cache the data and then send, such as
It is really no, then directly transmit the data.So, after the last batch of data is activation in the first time-domain OFDM symbol, step 201
It is carried out completing.
Step 203, after first time-domain OFDM symbol is sent, send the cyclic suffix data of caching, shape
Into the time domain orthogonal frequency division multiplexing symbol CPO-OFDM with cyclic suffix.
It should be noted that the cyclic suffix data of hair caching are all to be sent it in whole first time-domain OFDM symbol
Followed by send.So, the time domain CPO-OFDM symbols of formation are made up of two segment datas, before one section be complete first
Time-domain OFDM symbol, behind one section be cyclic suffix data, and the cyclic suffix data are the time-domain OFDM symbols of the last period first
In preceding L data, as shown in Figure 3.
It is understood that after the cyclic suffix in caching is sent, transmitting terminal is accorded with for first time domain OFDM
Number transmission be over, so, after step 203, can also be by the cyclic suffix of first time-domain OFDM symbol in caching
Data delete, so as to for followed by time-domain OFDM symbol transmissions vacate cache in memory space.
In addition, after step 203 is completed, transmitting terminal has completed the transmission to current first time-domain OFDM symbol, then may be used
Continue to obtain next formation time-domain OFDM symbol as the first current time-domain OFDM symbol using return to step 201, continued
The transmission of follow-up time-domain OFDM symbol in pairs.
Using the technical scheme of the present embodiment, by the guarantor that cyclic suffix data are added after each time-domain OFDM symbol
Shield is spaced to form CPO-OFDM symbols, only needs to wait whole time domain OFDM to accord with as the circulation follow-up data of protection interval
Number it is sent and could sends, so just only need to be cached after the time-domain OFDM symbol is formed the data of wherein cyclic suffix,
The data bulk of caching is needed so as to greatly reduce, and then reduces the RAM memory spaces for needing to take, so as to reduce
The consumption of RAM resources.
Due to RAM memory spaces shared when each time-domain OFDM symbol sends can be reduced, so the present embodiment
Technical scheme is particularly suited for the communication system of high speed ofdm signal treatment.Due to the communication system processed in high speed ofdm signal
In, the time-domain OFDM symbol quantity that inverse discrete Fourier transform is produced is very big, if using the transmission means of existing CP-OFDM
Need to increase the time-domain OFDM symbol that multiple RAM processes inverse discrete Fourier transform generation parallel, RAM consumptions can be into multiplication
Plus, so, it is necessary to make the time-domain OFDM symbol storage that FIFO generates inverse discrete fourier transformed using a large amount of RAM, according to
Secondary reading carries out CP insertion operations, CP-OFDM symbol datas then is sent into next stage, wherein in inverse discrete fourier transformed
Data input control and FIFO between need to carry out strict sequential order and design, it is ensured that FIFO not overflow and underflow.And use this implementation
The technical scheme of example, because each time-domain OFDM symbol needs the data of caching much smaller compared to whole symbol, even if so
Need to send all time-domain OFDM symbols that current discrete Fourier transformation produces also and do not need too many RAM memory spaces,
So the RAM quantity being accomplished by is much smaller than CP-OFDM transmission means, and then avoid the need for using above-mentioned CP-OFDM transmission means
Processing mode, so as to simplify generation OFMD time-domain symbols handling process complexity, improve system effectiveness.In addition, this
Embodiment is also resided in the difference of existing CP-OFDM transmission means, is to be sent out from caching in sending signal, in the present embodiment
Cyclic suffix data are sent, time-domain OFDM symbol is directly transmitted in itself, and existing CP-OFDM transmission means is then needed from caching
It is middle to send whole time domain CP-OFDM symbols, including time-domain OFDM symbol in itself with Cyclic Prefix data.So for a time domain
For OFDM symbol, the time that the present embodiment cache responses system sends data just reduces than existing CP-OFDM transmission means
One time span of time-domain OFDM symbol.For example, it is assumed that the length of time-domain OFDM symbol is N number of data, the length of protection interval
It is L data to spend, then cache responses system sends the time of data just for the time of L time domain data is long in the present embodiment
Degree, and existing CP-OFDM transmission means is then the N+L length of time domain data.As can be seen here, the present embodiment is relative to existing skill
Art, greatly reduces the time of caching process data is activation, such that it is able to improve the speed of cache responses system, improves system
Performance.
In addition, because the data for needing caching are reduced in the present embodiment, so the store tasks performed required for caching are just
Reduce therewith, so, it is also possible to improve the speed of cache responses system, improve the performance of system.
Referring to Fig. 4, the flow chart of the embodiment 2 of OFDM transmission method of the present invention is shown, the present embodiment is applied to receive
End, can include：
Step 401, reception time domain CPO-OFDM symbols；The time domain CPO-OFDM symbols use preceding method for transmitting terminal
The signal that embodiment 1 sends.
It should be noted that receiving terminal in the present embodiment and the transmitting terminal of step 101 are usually different in Transmission system
Equipment, wherein, the equipment can be terminal, or base station.
It is understood that usually can realize that each equipment is that have in the Transmission system of the inventive method embodiment simultaneously
There are the receiving terminal of the present embodiment and the transmitting terminal of above-described embodiment, just can normally be communicated between such equipment.
Step 402, preceding L data in the time domain CPO-OFDM symbols are deleted, obtain the second time-domain OFDM symbol.
In the time domain CPO-OFDM symbols formed by embodiment of the method 1, preceding L data are identical with rear L data
Data, wherein preceding L data constitute protection interval.And generally when time domain OFDM signal is received, preceding L data may
Receive the interference from CPO-OFDM above.So, used the preceding L data of time domain CPO-OFDM symbols in the present embodiment
Delete to obtain time-domain OFDM symbol therein, to eliminate this interference.
It should be noted that receiving terminal need it is final obtain is data that transmitting terminal sends in frequency domain data form, because
This, after step 402 execution completion obtains the second time-domain OFDM symbol, in addition it is also necessary to by the Symbol processing into frequency domain data.
In the present embodiment, the second time domain that the preceding L data of time domain CPO-OFDM symbols are obtained is removed by then passing through
OFDM symbol, so data in the first OFDM symbol that the order of data sends with transmitting terminal in second time-domain OFDM symbol
Order is different.Assuming that the length of time-domain OFDM symbol is N number of data, the length of protection interval is L data, then second when
Preceding N-L data in the OFDM symbol of domain are the rear N-L data in the first time-domain OFDM symbol, and the second time domain OFDM is accorded with
Rear L data in number are the preceding L data in the first time-domain OFDM symbol.
Because the data order in time-domain OFDM symbol is different, the second time-domain OFDM symbol is obtained by discrete Fourier transform
To the second frequency-domain OFDM symbol, also just the first frequency-domain OFDM symbol corresponding from transmitting terminal is different.So, in order to obtain transmitting terminal
The frequency domain data of transmission, it is necessary to be modified to the first frequency-domain OFDM symbol.
Referring to Fig. 5, the flow chart of the frequency domain data implementation method 1 of acquisition transmitting terminal transmission in the present embodiment is shown,
After step 402, present embodiment can include：
Step 501, discrete Fourier transform is carried out to second time-domain OFDM symbol, obtain the second frequency-domain OFDM symbol
Number；
Step 502, the position according to each data in the second frequency-domain OFDM symbol, in the second frequency-domain OFDM symbol
Each subcarrier data carries out corresponding phase compensation, to obtain the frequency that transmitting terminal is sent by the time domain CPO-OFDM symbols
Numeric field data.
Because the change in location distance of each data in time-domain OFDM symbol is simply with the data in time-domain OFDM symbol
The sequence of positions of appearance is relevant, so each frequency domain data in the second frequency-domain OFDM symbol obtained after discrete fourier change
Differed between the frequency domain data that simply corresponding with frequency domain data transmitting terminal sends one it is relevant with the sequence of positions of appearance
Fixed phase offsets.Specifically, it is assumed that the length of the second time-domain OFDM symbol is N number of data, and the length of protection interval is L
Data, k represents that the data for carrying out phase compensation are+1 data of kth in the second time-domain OFDM symbol, namely k is 0 to N-1
Between integer, so, the fixed phase offsets of the data are 2 π kL/N.
Based on this fixed phase offsets, the phase compensation that step 502 is carried out is -2 π kL/N, wherein, the second time domain
The length of OFDM symbol is N number of data, and the length of protection interval is L data, and k represents that the data for carrying out phase compensation are second
+ 1 data of kth in time-domain OFDM symbol.
By the technical scheme of present embodiment, it is possible to achieve receiving terminal gets hair by the second frequency-domain OFDM symbol
Frequency domain data transmitted by sending end.
Referring to Fig. 6, the flow chart of the frequency domain data implementation method 2 of acquisition transmitting terminal transmission in the present embodiment is shown,
After step 402, present embodiment can include：
Step 601, discrete Fourier transform is carried out to second time-domain OFDM symbol, obtain the second frequency-domain OFDM symbol
Number；
Step 602, the position according to each data in the second frequency-domain OFDM symbol, in being the second frequency-domain OFDM symbol
Each subcarrier data sets corresponding phase offset factor；
According to the above-mentioned explanation to step 502, each data has fixed phase offsets in the second frequency-domain OFDM symbol, because
This present embodiment is that each data sets corresponding phase offset factor and can be in the second frequency-domain OFDM symbol：To the data
Former phase offset factor carry out the amendment of -2 π kL/N, wherein, the length of the second time-domain OFDM symbol is N number of data, protection
The length at interval is L data, and k represents that the data for carrying out phase compensation are+1 data of kth in the second time-domain OFDM symbol.
Step 603, using corresponding phase offset factor to the son of each data in the second frequency-domain OFDM symbol
Carrier wave carries out sampling frequency offset correction, to obtain the frequency domain data that transmitting terminal is sent by the time domain CPO-OFDM symbols.
By the technical scheme of present embodiment, it is also possible to realize that receiving terminal is got by the second frequency-domain OFDM symbol
Frequency domain data transmitted by transmitting terminal.And present embodiment is with the difference of the implementation method 1 shown in Fig. 5, present embodiment
It is the sampling frequency offset correcting process during the reception using existing OFDM transmission come to the second frequency-domain OFDM symbol frequency domain number
According to phase offset corrected, it may not be necessary to for data order change causes the phase offset to increase in time-domain OFDM symbol
Single correction process process.
It is then returned to Fig. 4.
Using the technical scheme of the present embodiment, it is possible to achieve by receiving the CPO- transmitted by the inventive method embodiment 1
OFDM symbol and obtain the time-domain OFDM symbol transmitted by transmitting terminal and frequency domain data, also, the inventive method can also be made
The reception process of the CPO-OFDM symbols that embodiment 1 sends does not increase treatment relative to the reception process of existing CP-OFDM signals
Process, it is to avoid increase treatment complexity.
Corresponding to embodiment of the method, present invention also offers a kind of OFDM transmission device, transmitting terminal is applied to.Referring to Fig. 7,
The structure chart of OFDM transmission device embodiment 1 of the present invention is shown, the present embodiment is applied to transmitting terminal, and described device can be wrapped
Include：
OFDM acquisition modules 701, for obtaining the first time-domain OFDM symbol；
Cyclic suffix cache module 702, for using preceding L data in the first time-domain OFDM symbol as first time domain
The cyclic suffix data buffer storage of OFDM symbol；The L is the length value of the cyclic suffix；
OFDM sending modules 703, for sending first time-domain OFDM symbol；
Cyclic suffix sending module 704, for after first time-domain OFDM symbol is sent, sending the described of caching
Cyclic suffix data, form the time domain orthogonal frequency division multiplexing symbol CPO-OFDM with cyclic suffix.
Referring to Fig. 8, the structure chart of OFDM transmission device embodiment 2 is shown, the present embodiment is except including the institute shown in Fig. 7
Have outside structure, described device can also include：
Inverse transform module 801, for carrying out inverse discrete Fourier transform to the first frequency-domain OFDM symbol, obtains described first
Time-domain OFDM symbol.
Corresponding to embodiment of the method, present invention also offers a kind of OFDM transmission device, receiving terminal end is applied to.Referring to figure
9, the structure chart of OFDM transmission device embodiment 3 of the present invention is shown, the present embodiment is applied to receiving terminal, including：
Symbol receiver module 901, for receiving time domain CPO-OFDM symbols；The time domain CPO-OFDM symbols are transmitting terminal
The signal sent using the device described in claim 6 or 7；
Removing module 902, for preceding L data in the time domain CPO-OFDM symbols to be deleted, obtains the second time domain
OFDM symbol.
Referring to Figure 10, the structure chart of OFDM transmission device embodiment 4 is shown, the present embodiment is except including shown in Fig. 9
Outside all structures, described device can also include：
Conversion module 1001, for carrying out discrete Fourier transform to second time-domain OFDM symbol, obtains the second frequency
Domain OFDM symbol；
Subcarrier compensating module 1002, for the position according to each data in the second frequency-domain OFDM symbol, to described
Each subcarrier data carries out corresponding phase compensation in two frequency-domain OFDM symbols, to obtain transmitting terminal by the time domain CPO-
The frequency domain data that OFDM symbol sends.
Referring to Figure 11, the structure chart of OFDM transmission device embodiment 5 is shown, the present embodiment is except including shown in Fig. 9
Outside all structures, described device can also include：
Conversion module 1001, for carrying out discrete Fourier transform to second time-domain OFDM symbol, obtains the second frequency
Domain OFDM symbol；
Displacement factor setup module 1101, is described for the position according to each data in the second frequency-domain OFDM symbol
Each subcarrier data sets corresponding phase offset factor in second frequency-domain OFDM symbol；
Frequency deviation rectification module 1102, for using corresponding phase offset factor in the second frequency-domain OFDM symbol
Each subcarrier data carries out sampling frequency offset correction, to obtain the frequency domain that transmitting terminal is sent by the time domain CPO-OFDM symbols
Data.
Corresponding to embodiment of the method, the invention provides a kind of OFDM transmission system.Referring to Figure 12, the present invention is shown
The structure chart of OFDM transmission system embodiment 1, the present embodiment can include：Transmission end device 1201 shown in Fig. 7 or Fig. 8, and,
Any receiving end device 1202 shown in Fig. 9 ~ Figure 11.
Using apparatus of the present invention embodiment and the transmitting device and Transmission system of system embodiment, it is only necessary to when this is formed
The data of wherein cyclic suffix are cached after the OFDM symbol of domain, the data bulk of caching is needed so as to greatly reduce, and then reduce
The RAM memory spaces for taking are needed, so as to reducing the consumption of RAM resources.And, greatly reduce caching process data and
What is performed is stored and read out the handling process of task, so as to reduce the complexity of transmission processe.
It should be noted that herein, such as first and second or the like relational terms are used merely to a reality
Body or operation make a distinction with another entity or operation, and not necessarily require or imply these entities or deposited between operating
In any this actual relation or order.Term " including ", "comprising" or its any other variant be intended to non-row
His property is included, so that process, method, article or equipment including a series of key elements not only include those key elements, and
And also include other key elements being not expressly set out, or also include for this process, method, article or equipment institute are intrinsic
Key element.In the absence of more restrictions, the key element limited by sentence "including a ...", it is not excluded that including institute
Also there is other identical element in process, method, article or the equipment of stating key element.
For system embodiment, because it corresponds essentially to embodiment of the method, so related part is referring to method reality
Apply the part explanation of example.System embodiment described above is only schematical, wherein described as separating component
The unit of explanation can be or may not be physically separate, and the part shown as unit can be or can also
It is not physical location, you can with positioned at a place, or can also be distributed on multiple NEs.Can be according to reality
Selection some or all of module therein is needed to realize the purpose of this embodiment scheme.Those of ordinary skill in the art are not
In the case of paying creative work, you can to understand and implement.
The above is only the preferred embodiment of the present invention, it is noted that for the ordinary skill people of the art
For member, under the premise without departing from the principles of the invention, some improvements and modifications can also be made, these improvements and modifications also should
It is considered as protection scope of the present invention.
Claims (7)
1. a kind of orthogonal frequency division multiplex OFDM transmission method, it is characterised in that be applied to transmitting terminal, including：
Obtain the first time-domain OFDM symbol；
Using preceding L data in the first time-domain OFDM symbol as first time-domain OFDM symbol cyclic suffix data buffer storage,
The L is the length value of the cyclic suffix, and sends first time-domain OFDM symbol；
After first time-domain OFDM symbol is sent, the cyclic suffix data of caching are sent, formed with after circulation
The time domain orthogonal frequency division multiplexing symbol CPO-OFDM for sewing, so that receiving terminal receives the CPO-OFDM symbols, by the time domain
Preceding L data are deleted in CPO-OFDM symbols, obtain the second time-domain OFDM symbol, second time-domain OFDM symbol is carried out from
Fourier transformation is dissipated, the second frequency-domain OFDM symbol is obtained, is described according to the position of each data in the second frequency-domain OFDM symbol
Each subcarrier data sets corresponding phase offset factor in second frequency-domain OFDM symbol；Using corresponding phase offset factor pair
Each subcarrier data in the second frequency-domain OFDM symbol carries out sampling frequency offset correction, when passing through described to obtain transmitting terminal
The frequency domain data that domain CPO-OFDM symbols send.
2. method according to claim 1, it is characterised in that before the time-domain OFDM symbol of the acquisition first, also include：
Inverse discrete Fourier transform is carried out to the first frequency-domain OFDM symbol, first time-domain OFDM symbol is obtained.
3. a kind of OFDM transmission method, it is characterised in that be applied to receiving terminal, including：
Receive time domain CPO-OFDM symbols；The time domain CPO-OFDM symbols are transmitting terminal using the side described in claim 1 or 2
The signal that method sends；
Preceding L data in the time domain CPO-OFDM symbols are deleted, the second time-domain OFDM symbol is obtained；
Discrete Fourier transform is carried out to second time-domain OFDM symbol, the second frequency-domain OFDM symbol is obtained；
It is each subcarrier data in the second frequency-domain OFDM symbol according to the position of each data in the second frequency-domain OFDM symbol
Corresponding phase offset factor is set；
Sampling frequency offset is carried out to each subcarrier data in the second frequency-domain OFDM symbol using corresponding phase offset factor
Correction, to obtain the frequency domain data that transmitting terminal is sent by the time domain CPO-OFDM symbols.
4. a kind of OFDM transmission device, it is characterised in that be applied to transmitting terminal, including：
OFDM acquisition modules, for obtaining the first time-domain OFDM symbol；
Cyclic suffix cache module, for preceding L data in the first time-domain OFDM symbol to be accorded with as first time domain OFDM
Number cyclic suffix data buffer storage；The L is the length value of the cyclic suffix；
OFDM sending modules, for sending first time-domain OFDM symbol；
Cyclic suffix sending module, for after first time-domain OFDM symbol is sent, after sending the circulation of caching
Sew data, form the time domain orthogonal frequency division multiplexing symbol CPO-OFDM with cyclic suffix, so that receiving terminal receives the CPO-
OFDM symbol, preceding L data in the time domain CPO-OFDM symbols are deleted, and obtain the second time-domain OFDM symbol, to described the
Two time-domain OFDM symbols carry out discrete Fourier transform, obtain the second frequency-domain OFDM symbol, according in the second frequency-domain OFDM symbol
The position of each data, is that each subcarrier data sets corresponding phase offset factor in the second frequency-domain OFDM symbol；Adopt
Sampling frequency offset correction is carried out to each subcarrier data in the second frequency-domain OFDM symbol with corresponding phase offset factor, with
Just the frequency domain data that transmitting terminal is sent by the time domain CPO-OFDM symbols is obtained.
5. device according to claim 4, it is characterised in that also include：
Inverse transform module, for carrying out inverse discrete Fourier transform to the first frequency-domain OFDM symbol, obtains first time domain
OFDM symbol.
6. a kind of OFDM transmission device, it is characterised in that be applied to receiving terminal, including：
Symbol receiver module, for receiving time domain CPO-OFDM symbols；The time domain CPO-OFDM symbols are transmitting terminal using power
Profit requires the signal that the device described in 4 or 5 sends；
Removing module, for preceding L data in the time domain CPO-OFDM symbols to be deleted, obtains the second time-domain OFDM symbol；
Conversion module, for carrying out discrete Fourier transform to second time-domain OFDM symbol, obtains the second frequency-domain OFDM symbol
Number；
Displacement factor setup module, is second frequency domain for the position according to each data in the second frequency-domain OFDM symbol
Each subcarrier data sets corresponding phase offset factor in OFDM symbol；
Frequency deviation rectification module, for using corresponding phase offset factor to each subcarrier in the second frequency-domain OFDM symbol
Data carry out sampling frequency offset correction, to obtain the frequency domain data that transmitting terminal is sent by the time domain CPO-OFDM symbols.
7. a kind of OFDM transmission system, it is characterised in that including：Transmission end device described in claim 4 or 5, and, right will
Seek the receiving end device described in 6.
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| CN113709080B (en) * | 2021-08-27 | 2023-11-21 | 芯翼信息科技(上海)有限公司 | Method and device for receiving and caching |
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| CN1862386A (en) * | 2005-05-13 | 2006-11-15 | 株式会社东芝 | Pattern forming method and method of manufacturing semiconductor device |
| CN101006669A (en) * | 2004-08-17 | 2007-07-25 | Lg电子株式会社 | Method for detecting OFDM symbol timing in ofdm system |
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| CN1862386A (en) * | 2005-05-13 | 2006-11-15 | 株式会社东芝 | Pattern forming method and method of manufacturing semiconductor device |
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