CN100544239C - The deinterleaving method that is used for OFDM communications - Google Patents
The deinterleaving method that is used for OFDM communications Download PDFInfo
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- CN100544239C CN100544239C CNB038259761A CN03825976A CN100544239C CN 100544239 C CN100544239 C CN 100544239C CN B038259761 A CNB038259761 A CN B038259761A CN 03825976 A CN03825976 A CN 03825976A CN 100544239 C CN100544239 C CN 100544239C
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
- H04L1/0056—Systems characterized by the type of code used
- H04L1/0071—Use of interleaving
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/02—Arrangements for detecting or preventing errors in the information received by diversity reception
- H04L1/04—Arrangements for detecting or preventing errors in the information received by diversity reception using frequency diversity
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2602—Signal structure
Abstract
The present invention relates to a kind of deinterleaving method in ofdm system, this method is utilized the two-dimensional time-frequency structure of ofdm system.This method comprises the steps: available band is divided into plurality of sub-bands, and each sub-band includes only adjacent frequency basically; The constellation symbol sequence is mapped as the OFDM unit sequence, and at this, an OFDM unit comprises one group of constellation symbol, and after this step, constellation symbol is only with prescription formula or OFDM unit mode and processed; With, the OFDM unit sequence that interweaves, at this, each OFDM unit can be mapped on one of described sub-band.Preferably, carry out last step respectively, discretely for the real part and the imaginary part of OFDM unit.The invention still further relates to a kind of transmitter and system.
Description
Technical field
The present invention relates to field of wireless communications systems, relate in particular to the improvement deinterleaving method of a kind of OFDM of being used for (OFDM) communication.
Background technology
OFDM (OFDM) a kind ofly is implemented on the very noisy channel transmission technology of transmission high data rate with relatively low complexity, and is applied in digital audio broadcasting (DAB) and the digital video broadcasting (DVB).OFDM has some good properties, the robustness of for example high spectrum efficiency and channel scattering, and therefore, it will be used for the following broadband application such as digital mobile radio communication probably.
In brief, in ofdm system, data waiting for transmission are modulated to be spread on a large amount of carrier waves, and is proportional to carrier number and therefore reduction by the data rate that each carrier wave in these carrier waves passes on.That these carrier waves have is equal, accurately selected frequency interval, and the frequency band of subcarrier be not separately but overlapping.By using IFFT (inverse fast Fourier transform) conduct modulation, the interval of chooser carrier wave by this way:, can from the signal that receives, correctly recover, and all other signals are zero for the signal of certain subcarrier-modulated.The selection of carrying out the carrier spacing is to guarantee its orthogonality, and this also is the origin of OFDM.
Design suitable ofdm system and the scatter fading channel is transformed into the flat fading channel that need not advanced time-domain equalizer.Therefore this provides tangible enforcement advantage, because do not need equalizer and reduced the complexity of transceiver, but this has also caused system can not obtain the frequency diversity that channel provides.Opposite with carrier wave communication system (for carrier wave communication system, but the usable frequency diversity in the good equalizer bid of design), ofdm system must reach the more high-order diversity performance that wireless environment provides by means of specific method.
This is very known in the document of relevant OFDM, and an acceptable method of bid frequency diversity is to use coding (for example convolution code or turbo sign indicating number), and its modulated spread spectrum of output bit is on all subcarriers.As S.K.Wilson and J.M.Cioffi ' A comparison of a single-carriersystem using a DFE and a coded OFDM system in a broadcast Rayleigh-fadingcharnnel ' (information theory international symposium (ISIT), September nineteen ninety-five) as described in, as long as the order of diversity of coding is greater than the frequency diversity tuple of channel, then the method just can be caught the usable frequency diversity.
Because OFDM has created one group of flat fading channel effectively, therefore designing any technology of improving the communication performance on the flat fading channel can be applied on the OFDM.
A kind of method of improving the diversity performance of (promptly not having redundancy to be added on the message bit stream) signal of communication of not encoding usually in the flat fading channel is: increase the order of diversity of modulation symbol, promptly increase so-called modulation diversity.At ＂ Signal Space Diversity:A Power-and Bandwidth-Efficient DiversityTechnique for the Rayleigh Fading Channel ＂ (IEEE information theory journal, the 44th volume, the 4th phase, in July, 1998, Joseph Boutros and Emanuele Viterbo) in analyzed this alternative diversity technique.By some rotation is applied on traditional signal constellation (in digital modulation), so that the mode that any two constellation point obtain the different component of maximum quantity increases modulation diversity.Therefore the decline of the signal phasor that has transmitted is dispersed on many components and has realized better noise effect protection, because those components are subjected to different influence of fading, and does not have two somes meetings simultaneously destroyed.Shown in this document: when modulation diversity was big, the QAM of multidimensional (quadrature amplitude modulation) constellation became insensitive to declining.
; above-mentioned document has been supposed the desirable any special characteristics that interweaves and do not utilize ofdm system; particularly do not utilize any characteristic (in multi-user OFDM system, in each OFDM mark space, single user only uses the part of total usable spectrum) of multi-user OFDM system.The shortcoming of modulation diversity is: under imperfect situation about interweaving, performance gain may be inappreciable.
At the ＂ On of Dennis L.Goeckel and Ganesh Ananthaswamy the Design ofMultidimensional Signal Sets for OFDM Systems ＂ (ieee communication journal, the 50th volume, the 3rd phase, in March, 2002) further obtain the prior art of being correlated with in.In this document, developed ＂ for the OFDM transmission system of routine and merged the experimental process carrier wave, send the symbol ＂ in a multi-dimensional constellation.Advised a kind of coding modulation technique: picks symbols from the set of multidimensional complex signal, the selected subcarrier-modulated of each Wesy's ofdm system of selected symbol obtains diversity gain so then.In this document, in each OFDM mark space, the transmission of the constellation symbol component subcarrier-modulated of disperseing.This method has some shortcomings.At first, this document does not have to describe the application to multi-user system.Even it can be applied in the multi-user system, then because the dispersing characteristic of subcarrier also causes being difficult to carry out channel estimating.Secondly, because specific, off-gauge, irrotational constellation structures make that detection is more complicated; The 3rd, the performance in the Gaussian channel is not best.
On frequency selective fading channels, the diversity that typical uncoded ofdm system is realized obviously is less than the uncoded single-carrier system that uses suitable channel equalizer.A kind of method of reappearing the ofdm system frequency diversity is to use to encode/interweave on subcarrier, other method is to adopt high diversity symbol constellation (the limited real-valued set of vectors that bit shone upon behind the coding), the component that this high diversity symbol constellation has usually said signal space diversity or modulation diversity interweaves, the advantage of first method is: the diversity of bringing after the code redundancy has produced the additional performance gain, but cost is the increase of bandwidth.The advantage of second method is: needn't increase any bandwidth (not having redundancy) and just can obtain frequency diversity., two methods all require suitable interleaving scheme respectively symbol and sign component decorrelation.
Because an interleaving scheme may produce than the obvious worse performance of another interleaving scheme, so desirable OFDM interleaving scheme that provides, diversity performance in all coded OFDM systems of this scheme optimization, all coded OFDM systems comprise, the ofdm system that utilizes the ofdm system of redundancy encoding (such as convolution code) and utilize nonredundancy coding (such as modulation diversity).
Further, another purpose is: under the situation of multi-user OFDM, all users in the system can both obtain diversity gain.
Therefore, need a kind of OFDM deinterleaving method of optimizing the diversity performance of ofdm system.
Summary of the invention
The objective of the invention is to provide in ofdm system a kind of deinterleaving method, this method is used in the diversity performance optimization of the deversity scheme of creating frequency diversity.
Further aim of the present invention is that all users for ofdm system provide diversity gain.
A further object of the present invention is: compare with known multi-user OFDM system, higher frequency diversity is provided and does not need to increase bandwidth.Modulation diversity does not increase any redundancy to data flow, and can therefore obtain diversity performance gain when keeping data rate.
According to a first aspect of the invention, realize these purposes by a kind of deinterleaving method, a kind of transmitter and a kind of OFDM wireless communication system that is used for the signal communication between at least one transmitter and receiver that is applied in the ofdm system in ofdm system.
According to the present invention, a kind of interweaving method that is used in ofdm system is provided, wherein said method has been utilized the two-dimensional time-frequency structure of ofdm system.This method comprises the steps: available band is divided into plurality of sub-bands, and each sub-band includes only necessary side frequency; The constellation symbol sequence is mapped to the OFDM unit sequence, and wherein, defining an OFDM unit is one group of constellation symbol, and after this step, constellation symbol is only processed in the mode of prescription formula or OFDM unit; The OFDM unit sequence that interweaves, wherein, each OFDM unit can be mapped on one of described sub-band.Preferably, for the real part and the imaginary part of OFDM unit, carry out described interweaving respectively, discretely.
According to one embodiment of present invention, the step that available OFDM frequency bandwidth is divided into plurality of sub-bands comprises: the sub-band that frequency band division is become equal sizes.This feature provides simple available resources management.For example, can carry out channel allocation in a simple manner to a large number of users.Therefore the sub-band that uses unequal frequency also is possible, and provides very big design flexibility to the operator of mobile communication system.
According to another embodiment of the present invention, this method is carried out after the constellation mapping step.Therefore, this is additional the interweaving of not carrying out in the prior art.This adds the step that interweaves, and has utilized the T/F dependency structure of ofdm system, and additional diversity is provided.
According to another embodiment of the present invention, the step of mapped constellation symbol sebolic addressing comprises: after the interweaving of the rotation of constellation symbol and constellation symbol component, constellation symbol mapped to the OFDM unit.According to this feature, after the interweaving of the component of constellation symbol, carry out additional interweaving, thereby additional diversity is provided.
According to another embodiment of the present invention, the step that interweaves is the time and the frequency map of described OFDM unit sequence, wherein, distributes to Transmission Time Interval and interior unique time and the frequency band of available spectrum that can use each OFDM unit.By means of this, the special time-frequency dependence of OFDM flat fading channel is considered, and has obtained the frequency diversity of channel-attach.
According to another embodiment of the present invention, employed mapping mode is randomized T/F mapping.Can find out this at random mapping mode good diversity performance is provided, but can make otherwise too.For example, for different users, only may use mapping modes different on time or frequency.
The invention still further relates to a kind of transmitter, this transmitter comprises the device that is used to carry out this deinterleaving method.The invention still further relates to a kind of communication system that comprises at least one described transmitter.
Above-mentioned attendant advantages is realized by transmitter and the system that the embodiment of the invention provides respectively.
When the present invention being applied to turbo coded system (or other method of use soft-decision), improved the soft bit of presenting to the first order of iterative decoder.Therefore, decoded bit has the mistake probability lower than the system that does not obtain this diversity.
And when being applied to multi-user system, all users in the system will obtain similar diversity by means of the present invention and improve.
The present invention also provides a kind of method, and it can be easy to merge with existing OFDM standard, thereby makes it become very attractive alternative.
Description of drawings
Fig. 1 shows the method for prior art.
Fig. 2 shows the basis of ofdm system.
Fig. 3 shows according to the legend of the afterbody of OFDM transmitter base band level of the present invention, OFDM unit and the grouping of frequency band.
Fig. 4 shows typical downlink transmitter handle link.
Fig. 5 shows the final stage according to OFDM transmitter processes link of the present invention.
Fig. 6 a-d shows and is used for the present invention's T/F mapping mode exemplary.
Fig. 7-8 shows some experimental results.
Embodiment
As what explain in introduction part, OFDM has created one group of flat fading channel effectively, and any technology that is designed to improve the communication performance on the flat fading channel can be applied on the OFDM., the certain relevant structure of OFDM flat fading channel provides the special chance of improving, and this point is recognized by inventor of the present invention.Specifically, the multicarrier system such as OFDM has two-dimensional structure (time dimension and frequency dimension), and this structure provides the condition of diversity gain respectively for the designer from frequency dependence and time correlation.
In multi-user OFDM system, single user only uses the part of total usable spectrum in each OFDM mark space.The chance that it provides additional T/F to interweave, for example with existing data bit interweave and constellation mapping combines, also can obtain the potential frequency diversity gain of channel.
As previous description, at the document ＂ of Joseph Boutros and Emanuele Viterbo SignalSpace Diversity:A Power-and Bandwidth-Efficient Diversity Technique for theRayleigh Fading Channel ＂ (IEEE information theory journal, the 44th volume, a method that realizes modulation diversity is provided the 4th phase, in July, 1998).As previous explanation, the key that increases modulation diversity is so that any two constellation point obtain the mode of different component as much as possible that some rotation is applied on traditional signal constellation (in digital modulation).Such rotary manipulation will not change the performance on AWGN (additive white Gaussian noise) channel, but will improve the performance on smooth Rayleigh (Rayleigh) fading channel.The basic necessary condition of this type of improved performance is: the real part of transmission signals and imaginary part are incoherent.In order to create this necessary condition, in one of signal in orthogonal branch, introduce so-called component interleaver.Component interleaver has been destroyed the correlation between homophase and the quadrature signal component, so that the institute of the constellation symbol of transmission has only one-component experience deep fading in important.
The method of above-mentioned prior art as shown in Figure 1.Inventor of the present invention has realized that this method that can adjust and realize finishing according to the present invention in ofdm system.Fig. 2 has illustrated that FFT in the ofdm system (fast Fourier transform) and Cyclic Prefix are for conversion into the flat Rayleigh fading channel to scatter channel, and inventor of the present invention has realized that therefore modulation diversity is applicable to ofdm system.Correspondingly, the present invention relates to a kind of method, this method is compared with the modulation diversity gain described in the top list of references, based on the interval of OFDM unit in time and frequency, further amplifies diversity gain by reasonable time-frequency interlacing in multi-user OFDM.The T/F interleaver of OFDM unit makes each uncorrelated as far as possible in frequency domain and time domain to the constellation symbol that receives to the OFDM unit.
With reference now to Fig. 3,, with some essential characteristics of description OFDM transmitter and according to feature of the present invention.Here, definition OFDM unit is the one group of constellation symbol that is mapped to one of interior some equal sub-bands of total usable spectrum.According to the present invention, preferably, total frequency spectrum is divided into equal sub-band.The frequency sub-bands that equates is preferred, because help resource management (for example more easily distributing available resources), but the sub-band that is divided into non-equal frequencies also is possible.The OFDM unit is fed in inverse fast Fourier transform (IFFT) processor, at this, finishes pulse shaping and modulation.In receiver, utilize fast Fourier transform to finish opposite operation, this is conventionally known to one of skill in the art.Signal is fed to and string location (P/S) then, and at this, N parallel data stream is combined to be a data flow.After this, add Cyclic Prefix.
With reference now to Fig. 4,, Fig. 4 has described the exemplary process of being finished by transmitter on the down link of mobile communication system.At first bit block is carried out Cyclic Redundancy Check, for example use convolutional encoding or turbo to encode then.Then, consequent bit block is perforated and is interleaved and is mapped on the constellation of complex.After this one-level, a N is just arranged here
sThe constellation symbol of individual complex values.Detail with reference third generation partnership project 3GPP TS 25.212V5.2.0 (2002-09) (for example the 4.2nd chapter).
One embodiment of the present of invention are relevant with the decline of transmitter processes link: N
sThe mapping (by subcarrier pointer and OFDM mark space pointer characterize) of individual constellation symbol to the OFDM physical resource, perhaps physical channel mapping., can carry out in the other places in transmission link according to deinterleaving method of the present invention.Finally, N
sEach symbol in the individual constellation symbol is mapped as the part (sub-carrier frequency) of OFDM mark space and FFT by this OFDM physical channel.The present invention is subdivided into three phases to the universal architecture of OFDM physical channel mapping, as what will describe with reference to figure 4.
Compare (＂ On the Design of Multidimensional Signal Setsfor OFDM Systems ＂) with the art methods of transmitting the constellation symbol component with reference to the top subcarrier that use disperses in each OFDM mark space, the present invention divides into groups to adjacent subcarrier.Though most of sub-band frequency is adjacent one another are, some frequencies that depart from can form the part of sub-band.These frequencies that depart from will be used for non-customer service, for example pilot signal.This class of subcarrier is assembled by providing better channel estimating condition to simplify channel estimating.The OFDM channel estimation methods utilizes the strong correlation of the channel fading between the adjacent sub-carrier usually.Therefore, the decay of a known frequency, this known decay or decline that can be used to estimate side frequency.Therefore, (that is, known signal sequence whether) needs or not for each frequency sends a pilot signal, and can save the resource of shortage and the data rate of raising user data thus to have reduced pilot signal transmitted.
Therefore two conflicting aspects are arranged: the interval between hope group and the group is big as far as possible on the one hand, so that realize diversity; Interval between hope group on the other hand and the group is as far as possible little, because this will help channel estimating.The present invention has conciliate this two aspects, because available band is divided into plurality of sub-bands (that is, having only adjacent sub carrier group to be assembled basically) and modulation diversity (by reasonable time-frequency interlacing) is provided simultaneously.
As explained before, the T/F interleaver of OFDM unit makes each uncorrelated as far as possible in frequency domain and time domain to the constellation symbol that receives to the OFDM unit.Especially, and with reference to figure 4, OFDM T/F interleaver according to the present invention was made up of following three root phases:
1. the constellation symbol sequence is to the mapping of OFDM unit sequence.After this stage, constellation symbol is only processed in the mode of the mode of group or OFDM unit.Specifically, after the interweaving of the rotation of constellation symbol and constellation symbol component, finish the mapping of constellation symbol to the OFDM unit.
2.OFDM the unit interweaves.The OFDM unit sequence is interleaved.This is that one additional (when being used in described example) interweaves, and it is not performed in the prior art, and preferably, interweaves respectively for the real part and the imaginary part of OFDM unit.
3.OFDM the T/F of unit sequence mapping (i.e. one group of constellation symbol).Wherein, each OFDM unit is assigned with unique time and the frequency band in available Transmission Time Interval and the available spectrum.
At first, after constellation mapping, consequent N
sIndividual constellation symbol is mapped to N
OFDMOn the individual OFDM unit.Each OFDM unit is one group of constellation symbol here, and all usually OFDM unit comprise the constellation symbol of equal amount.The grouping constellation symbol so that each group can be mapped on the specific frequency sub-bands.
Secondly, by considering 2 dimension correlation properties of wireless channel, the OFDM unit interleaver is used for optimizing the performance (appearing at previously in the transmitter chain, referring to Fig. 3) of bit interleaver.The OFDM unit interleaver can be by N
OFDMThe permutation vector I of individual continuous OFDM unit describes.By permutation vector I=[1 2 3...N are set
OFDM], can make the OFDM unit interleaver apparent.
According to preferred embodiment, shine upon the real part and the imaginary part of OFDM unit respectively.Obtain better diversity gain thus, and resist the noise effect that is present in the system more efficiently, do not experience the deep fading because suppose these two components.The real part of signal is mapped on the particular sub-band and imaginary part is mapped on other sub-band.
At last, the OFDM unit sequence that is interleaved is mapped on the physical channel.For this purpose, as mentioned above, whole available OFDM frequency band is divided into N
BIndividual frequency sub-bands.Single physical channel is at N
Sym_intOnly use 1/N in the individual OFDM unit interval duration
BTotal available aggregate resources, mean: have up to N
BIndividual concurrent user or have up to N for unique user
BIndividual parallel physical channel has been realized the data rate that is exceedingly fast of unique user.
The size of OFDM unit (being number of constellation symbols) is such: so that each frequency sub-bands comprises an OFDM unit in each OFDM mark space.This refers to can transmit in each OFDM mark space N at most
BIndividual parallel OFDM unit.
When carrying out T/F (T-F) mapping of phase III, each user can specify specific pattern, referring to Fig. 6 a-d.In Fig. 6 a-d, the different mode that is used for the phase III has been described, and four different patterns exemplary, N have been shown
B=15 and N
Sym_int=12 and N
OFDM=12.Attention: N
OFDM=N
Sym_intIt must not this situation.If these parameter difference, then N
BN
Sym_intIndividual resource can be fit to surpass N
BThe N of individual OFDM unit
OFDMStream.
Randomized T-F mapping D is a preferred embodiment among Fig. 6 d, and show ITU-channel VA120 (the vehicle A of 120km/h with regard to bit error rate and frame error rate aspect, details is referring to 3GPP TR25.890 V1.0.0,2002-05) and PB3 (the pedestrian B of 3km/h, details is referring to 3GPP TR 25.890V1.0.0,2002-05) the optimum performance A-D of the mapping of the T-F in some channel circumstance shown in Fig. 6 a-d.Fig. 7 shows some test results, and the performance of the T-F mapping of Fig. 6 a-d has been described.In Fig. 7, drawn channel circumstance (vehicle A, the bit error rate (BER) during 120km/h) mapping shown in Fig. 6 a-d of ITU regulation.Randomized T-F mapping D is a preferred embodiment among Fig. 6 d, and shows the optimum performance in channel circumstance necessarily that can see as institute in Fig. 8.In Fig. 8, drawn channel circumstance (vehicle A, the bit error rate (BER) during 120km/h) mapping shown in Fig. 6 d of ITU regulation again.In coding and uncoded situation and modulation diversity is arranged and do not have the situation of modulation diversity and test.In the turbo decoder, carry out iteration eight times.Just as can be seen, greatly improved performance according to modulation diversity method of the present invention.
The T/F mapping of OFDM unit is characterized by two parameters of each OFDM unit: an indication OFDM symbol time is indicated selected frequency sub-bands for one at interval.These parameters can concentrate on the scope of being contained in 1, N
OFDMIn OFDM mark space index the T vector and be contained in scope 1, N
BIn the F vector of each corresponding sub-band index in OFDM unit in.For k input of OFDM unit, its T-F mapping is determined by the T and the F value of k position correspondence.
The mapping of using will produce optimally diversified performance in any channel circumstance.Should be like this: make each uncorrelated as far as possible in frequency domain and time domain to the constellation symbol that receives to the OFDM unit.
A typical way of division signals component is that they are divided into real part and imaginary part respectively, perhaps is equal to ground, and they are divided into homophase and quadrature component.When the method according to this invention was improved performance in conjunction with modulation diversity, real part and imaginary part respectively importantly interweaved.When the method according to this invention is generally used for improving the performance of coded OFDM system, can finish interweaving of OFDM unit sequence according to other mode.
Can finish mapping by means of trial-and-error method (trial-and-error) in one embodiment, perhaps can finish it according to the selection of channel in another embodiment.
As well known in the art, soft-decision decoding has brought stronger certainty to decoding, because considered the symbol of received signal (hard decision) and the tolerance of amplitude.Data are modulated onto on several carrier waves in ofdm system, and different carrier waves will have different signal to noise ratios and will therefore experience different declines.Preferably, real part and imaginary part because the method according to this invention interweaves on different sub-bands respectively, then the probability all lost of two components is very little, perhaps changes a kind of saying, and the probability that then receives at least one component that does not worsen is bigger.Therefore, when the present invention being applied to the system of turbo coding (perhaps using other system of soft-decision), then improved the soft bit of presenting to first order iterative decoder.Therefore, decoded bit will have the mistake probability lower than the system that does not obtain this diversity.
The present invention can be used in the high speed descending sharing channel (HS-DSCH) based on third generation cellular system in the transmission system of multi-user OFDM.
The invention provides a kind of method that can be easy to merge or be easy to be increased on the existing standard with existing standard, ETSI 3GPP TS 25 212 V5.2.0 (2009-09) for example, 3GPP TSG RAN: multiplexed and chnnel coding (FDD) (version 5).Therefore the present invention is very attractive and has the alternative of practicality.
The present invention combines preferred embodiment and is described.Clearly, consider foregoing description, a lot of selections, modification, variation and use will be conspicuous for a person skilled in the art.For example, described according to deinterleaving method of the present invention in conjunction with the channel Mapping level., the present invention is not restricted to this, and (and may be unique) interweaves can be used for first according to deinterleaving method of the present invention, perhaps as the step that interweaves in other place in the chain.Those skilled in the art can be implemented in to receive and finish corresponding deinterleaving in the link.
Claims (19)
1. deinterleaving method in ofdm system is characterized in that: described method adopts the two-dimensional time-frequency structure of ofdm system, and comprises the steps:
Available band is divided into plurality of sub-bands, and each sub-band comprises adjacent frequency,
The constellation symbol sequence is mapped as the OFDM unit sequence, and wherein, defining an OFDM unit is one group of constellation symbol, and after this step, constellation symbol is only processed in the mode of group;
The OFDM unit sequence that interweaves, wherein, each OFDM unit is mapped on one of described sub-band.
2. deinterleaving method as claimed in claim 1 is characterized in that: the described step that available band is divided into plurality of sub-bands comprises: the sub-band that frequency band division is become equal sizes.
3. deinterleaving method as claimed in claim 1 is characterized in that: the described step that available band is divided into plurality of sub-bands comprises: the sub-band that frequency band division is become non-equal sizes.
4. as any one described deinterleaving method of claim 1-3, it is characterized in that: the step of the described OFDM of interweaving unit sequence comprises: interleaved signal component respectively.
5. deinterleaving method as claimed in claim 4 is characterized in that: the step of the described OFDM of interweaving unit sequence comprises: real part and imaginary part discretely interweave respectively.
6. as any one described deinterleaving method of claim 1-3, it is characterized in that: after the constellation mapping step, carry out this method.
7. as any one described deinterleaving method of claim 1-3, it is characterized in that: the step of described mapped constellation symbol sebolic addressing comprises: the rotation constellation symbol after constellation symbol mapped to the OFDM unit.
8. as any one described deinterleaving method of claim 1-3, it is characterized in that: time and frequency map that the described step that interweaves is the OFDM unit sequence, wherein, be unique time and frequency band in each OFDM unit distribution available transmission time interval and the usable spectrum.
9. as any one described deinterleaving method of claim 1-3, it is characterized in that: the mapped mode that employed each OFDM unit is mapped on one of described sub-band is randomized T/F mapping.
10. as any one described deinterleaving method of claim 1-3, it is characterized in that: this method is used for multi-user environment.
11. a transmitter that is applied in the ofdm system is characterized in that: this transmitter comprises,
Be used for available band is divided into the device of plurality of sub-bands, each sub-band comprises side frequency;
Be used for the constellation symbol sequence is mapped as the device of OFDM unit sequence, wherein, an OFDM unit is defined as one group of constellation symbol, and after this, constellation symbol is only processed in the mode of group;
Be used to the to interweave device of OFDM unit sequence, the real part and the imaginary part of the OFDM unit that interweaves discretely respectively, wherein, each OFDM unit is mapped on one of described sub-band.
12. transmitter as claimed in claim 11 is characterized in that: the described device that is used for available band is divided into plurality of sub-bands comprises, frequency band division is become the device of the sub-band of equal sizes.
13. transmitter as claimed in claim 11 is characterized in that: the described device that is used for bandwidth available is divided into plurality of sub-bands comprises, frequency band division is become the device of the sub-band of non-equal sizes.
14. as any one described transmitter of claim 11-13, it is characterized in that: the device of the described OFDM unit sequence that is used to interweave comprises and is used for the device of interleaved signal component discretely.
15. transmitter as claimed in claim 14 is characterized in that: the device of the described OFDM of interweaving unit sequence comprises the device of be used for interweaving discretely respectively real part and imaginary part.
16. as any one described transmitter of claim 11-13, it is characterized in that: the described device that is used for the mapped constellation symbol sebolic addressing comprises and being used for after the rotation constellation symbol the device of constellation symbol mapped to the OFDM unit.
17. as any one described transmitter of claim 11-13, it is characterized in that: the described device that is used to interweave comprises: be used for the time of OFDM unit sequence and the device of frequency map, wherein, each OFDM unit is assigned to unique time and the frequency band in the available transmission time interval and the usable spectrum.
18. as any one described transmitter of claim 11-13, it is characterized in that: the mapped mode that employed each OFDM unit is mapped on one of described sub-band is randomized T/F mapping.
19. an OFDM wireless communication system that is used for the signal communication between at least one transmitter and receiver, described communication system comprises any one described at least one transmitter as claim 11-18.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/CN2003/000133 WO2004073219A1 (en) | 2003-02-14 | 2003-02-14 | Interleaving method for ofdm communications |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200910168896 Division CN101677309B (en) | 2003-02-14 | 2003-02-14 | Launcher, interleaver and interleaving method |
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| CN1742450A CN1742450A (en) | 2006-03-01 |
| CN100544239C true CN100544239C (en) | 2009-09-23 |
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| AU (1) | AU2003218598A1 (en) |
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| US7042857B2 (en) | 2002-10-29 | 2006-05-09 | Qualcom, Incorporated | Uplink pilot and signaling transmission in wireless communication systems |
| US7177297B2 (en) | 2003-05-12 | 2007-02-13 | Qualcomm Incorporated | Fast frequency hopping with a code division multiplexed pilot in an OFDMA system |
| US8611283B2 (en) | 2004-01-28 | 2013-12-17 | Qualcomm Incorporated | Method and apparatus of using a single channel to provide acknowledgement and assignment messages |
| EP1763932A4 (en) | 2004-02-17 | 2010-01-06 | Huawei Tech Co Ltd | Multiplexing scheme in a communication system |
| US8891349B2 (en) | 2004-07-23 | 2014-11-18 | Qualcomm Incorporated | Method of optimizing portions of a frame |
| US8238923B2 (en) | 2004-12-22 | 2012-08-07 | Qualcomm Incorporated | Method of using shared resources in a communication system |
| US8831115B2 (en) | 2004-12-22 | 2014-09-09 | Qualcomm Incorporated | MC-CDMA multiplexing in an orthogonal uplink |
| CN101145828B (en) * | 2006-09-11 | 2012-01-25 | 华为技术有限公司 | A data transmission method and device based on minimum coverage |
| CN102984824B (en) * | 2006-09-29 | 2015-12-23 | 松下电器（美国）知识产权公司 | The sending method that terminal installation and terminal installation perform |
| TWI474693B (en) * | 2008-03-10 | 2015-02-21 | Koninkl Philips Electronics Nv | Techniques for multiple-subcarrier joint precoding |
| TWI458301B (en) * | 2008-03-11 | 2014-10-21 | Koninkl Philips Electronics Nv | A flexible structure for multiple-subcarrier joint modulation ofdm transmitters |
| TWI458302B (en) | 2008-03-11 | 2014-10-21 | Koninkl Philips Electronics Nv | A method for accelerating the precoding and pre-decoding of symbols in ofdm systems |
| WO2010055989A1 (en) * | 2008-11-13 | 2010-05-20 | Lg Electronics Inc. | Apparatus for transmitting and receiving a signal and method of transmitting and receiving a signal |
| CN103873187B (en) * | 2012-12-11 | 2017-07-07 | 清华大学 | Deinterleaving method and device in ofdm system |
| GB2532233A (en) * | 2014-11-12 | 2016-05-18 | Sony Corp | Transmitter and receiver and methods of transmitting and receiving |
| GB2540593A (en) | 2015-07-22 | 2017-01-25 | Sony Corp | Receiver and method of receiving |
| GB2540594A (en) | 2015-07-22 | 2017-01-25 | Sony Corp | Receiver and method of receiving |
| GB2540595A (en) | 2015-07-22 | 2017-01-25 | Sony Corp | Receiver and method of receiving |
| CN105356905B (en) * | 2015-10-16 | 2017-09-29 | 上海磐启微电子有限公司 | A kind of direct sequence spread spectrum codes and 1/K rate convolutional code hybrid coding methods |
| CN111130687B (en) * | 2018-11-01 | 2022-08-02 | 中兴通讯股份有限公司 | Wireless data communication method and device, storage medium and electronic device |
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| FR2721461B1 (en) * | 1994-06-16 | 1996-09-06 | France Telecom | Signal formed by a plurality of orthogonal carrier frequencies organized so as to simplify the reception of one of the source signals composing it, corresponding transmission method and receiver. |
| DE19609909A1 (en) * | 1996-03-14 | 1997-09-18 | Deutsche Telekom Ag | Method and system for OFDM multicarrier transmission of digital radio signals |
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| 一种新的地面数字多媒体/电视广播传输系统. 杨林等.数字电视与数字视频，第2002年第1期. 2002 |
| 一种新的地面数字多媒体/电视广播传输系统. 杨林等.数字电视与数字视频，第2002年第1期. 2002 * |
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| AU2003218598A1 (en) | 2004-09-06 |
| WO2004073219A1 (en) | 2004-08-26 |
| CN1742450A (en) | 2006-03-01 |
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