CN101924720B - Sub-carrier processing method, device and system - Google Patents

Abstract

The embodiment of the invention relates to a sub-carrier processing method, a sub-carrier processing device and a sub-carrier processing system. The method comprises the following steps of: selecting sub-carriers of other user terminals as remaining sub-carriers corresponding to data sub-carriers of the current user terminal, wherein the data sub-carriers of the current user terminal are all sub-carriers allocated to the current user terminal, and all wavebands of the data sub-carriers of the current user terminal are used for transmitting data signals; and modulating a peak clipping sequence corresponding to a frequency domain signal transmitted by the current user terminal on the remaining sub-carrier. The device comprises a selection module and a modulation module. The embodiment of the invention reduces peak-to-mean ratio while preventing resource waste, and a receiver does not need to be redesigned.

Description

Sub-carrier processing method, device and system

Technical field

The embodiment of the invention relates to wireless communication technology field, relates in particular to a kind of sub-carrier processing method, device and system.

Background technology

OFDM (Orthogonal Frequency Division Multiplexing, hereinafter to be referred as: OFDM) be a kind of multi-carrier modulation.The main thought of OFDM technology is, carrier wave is divided into some orthogonal sub-carriers, converts high-speed data signal to parallel low speed sub data flow, is modulated on each subcarrier and transmits, the corresponding user terminal of each subcarrier.Because OFDM has characteristics such as availability of frequency spectrum height and anti-multipath interference, therefore be widely used in wireless communication technology field.

A subject matter that adopts OFDM to carry out carrier modulation is that peak-to-average force ratio is too high.So-called peak-to-average force ratio is exactly the maximum energy value that transmits and the ratio of the average energy value.Fig. 1 is the oscillogram of the transmitting power amplitude of an OFDM symbol in the prior art; As shown in Figure 1, the amplitude about the 450th sampled point is the peak value that transmits, and the average that this peakedness ratio transmits exceeds a lot; The excursion that is transmit signal power is excessive; This just requires the parts such as power amplifier of system that enough big dynamic range is arranged, in case dynamic range can not reach requirement, then can cause transmit power limited.In the practical communication process, the too high problem of peak-to-average force ratio is for up user terminal, and the user terminal influence that especially is in cell edge is bigger.The user terminal of cell edge needs higher transmitting power, and it transmits and just can effectively be received by the base station, if transmit power limited then can be brought the low problem of received signal to noise ratio.Prior art adopts frequency spectrum to keep algorithm reduction peak-to-average force ratio.Keep in the algorithm at frequency spectrum, for being the subcarrier that some user terminals distribute, transmitter as keeping subcarrier, is keeping the sequences of only modulating some process designs on the subcarrier, i.e. peak clipping sequence with a part of subcarrier then.Because the peak clipping sequence on the frequency domain is converted into after the time-domain signal; Peak at former time-domain signal also can generate spike; And the spike of the corresponding time-domain signal of peak clipping sequence and the spike of former time-domain signal are reverse; So after the two stack, the peak value of former time-domain signal will be cut down, thereby can reduce the peak-to-average force ratio of the ofdm signal that need transmit at the active user terminal.

In realizing process of the present invention; The inventor finds that there is following problem at least in prior art: frequency spectrum keeps algorithm and has kept a part of subcarrier for the modulation peak clipping sequence; Cause the waste of transfer resource; And, must dispose corresponding recognition mechanism and discern the subcarrier that is used to transmit data and be used to modulate the reservation subcarrier of peak clipping sequence, thereby cause the receiver complex design for receiver.

Summary of the invention

The embodiment of the invention provides a kind of sub-carrier processing method, device and system, when reducing peak-to-average force ratio, has reduced the complexity of the waste and the receiver design of transfer resource.

The embodiment of the invention provides a kind of sub-carrier processing method, comprising:

Select the subcarrier conduct reservation subcarrier corresponding of other user terminal with the data subcarrier at active user terminal; The data subcarrier at said active user terminal is all subcarriers that said active user's terminal distribution arrives, and whole wave bands of the data subcarrier at said active user terminal are used for transmission of data signals;

The peak clipping sequence corresponding with the frequency-region signal of said active user's terminal transmission is modulated on the said reservation subcarrier.

The embodiment of the invention also provides a sub-carrier processing unit, comprising:

Select module; Be used to select the subcarrier conduct reservation subcarrier corresponding of other user terminal with the data subcarrier at active user terminal; The data subcarrier at said active user terminal is all subcarriers that said active user's terminal distribution arrives, and whole wave bands of the data subcarrier at said active user terminal all are used for transmission of data signals;

Modulation module is used for the peak clipping sequence corresponding with the frequency-region signal of said active user's terminal transmission is modulated at said reservation subcarrier.

The embodiment of the invention also provides a kind of multicarrier system, comprises subcarrier processing unit and receiving system,

Said subcarrier processing unit; Be used to select the subcarrier conduct reservation subcarrier corresponding of other user terminal with the data subcarrier at active user terminal; The data subcarrier at said active user terminal is all subcarriers that said active user's terminal distribution arrives, and whole wave bands of the data subcarrier at said active user terminal are used for transmission of data signals; The peak clipping sequence corresponding with the frequency-region signal of said active user's terminal transmission is modulated on the said reservation subcarrier;

Said receiving system is used to receive said frequency-region signal, and said frequency-region signal is handled.

The embodiment of the invention through with the subcarrier of other user terminal as the reservation subcarrier corresponding with the data subcarrier at active user terminal; And on this reservation subcarrier, modulate peak clipping sequence; Make whole wave bands of data subcarrier at active user terminal can both be used for transmission of data signals; Therefore, when reducing peak-to-average force ratio, can also avoid the waste of transfer resource; And; Because any variation does not take place in the data subcarrier at active user terminal; The subcarrier of other user terminal only is equivalent to introduce controlled noise; Therefore for receiver, need not change to accomplish whole user terminals are carried out the operation of demodulation through the data subcarrier data signals transmitted, thereby can not improve the design complexities of receiver.

Description of drawings

In order to be illustrated more clearly in the embodiment of the invention or technical scheme of the prior art; To do one to the accompanying drawing of required use in embodiment or the description of the Prior Art below introduces simply; Obviously, the accompanying drawing in describing below is some embodiments of the present invention, for those of ordinary skills; Under the prerequisite of not paying creative work property, can also obtain other accompanying drawing according to these accompanying drawings.

Fig. 1 is the oscillogram of the transmitting power amplitude of an OFDM symbol in the prior art;

The flow chart of the embodiment of sub-carrier processing method that Fig. 2 provides for the embodiment of the invention;

Obtain the flow chart of the peak clipping sequence that is used for modulation treatment among another embodiment of sub-carrier processing method that Fig. 3 provides for the embodiment of the invention;

Obtain the flow chart of the peak clipping sequence that is used for modulation treatment among another embodiment of sub-carrier processing method that Fig. 4 provides for the embodiment of the invention;

The sub-carrier processing method that Fig. 5 provides for the embodiment of the invention also obtains the flow chart of the peak clipping sequence that is used for modulation treatment among embodiment;

The sub-carrier processing method that Fig. 6 provides for the embodiment of the invention obtains the flow chart of the peak clipping sequence that is used for modulation treatment again among another embodiment;

The sub-carrier processing method that Fig. 7 provides for the embodiment of the invention obtains the flow chart of the peak clipping sequence that is used for modulation treatment again among another embodiment;

Fig. 8 goes back the flow chart that obtains the peak clipping sequence that is used for modulation treatment among the embodiment again for the sub-carrier processing method that the embodiment of the invention provides;

The structural representation of the embodiment of subcarrier processing unit that Fig. 9 provides for the embodiment of the invention;

The structural representation of another embodiment of subcarrier processing unit that Figure 10 provides for the embodiment of the invention;

The structural representation of the embodiment of multicarrier system that Figure 11 provides for the embodiment of the invention.

Embodiment

To combine the accompanying drawing in the embodiment of the invention below, the technical scheme in the embodiment of the invention is carried out clear, intactly description, obviously, described embodiment only is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills are not making the every other embodiment that is obtained under the creative work prerequisite, all belong to the scope of the present invention's protection.

The flow chart of the embodiment of sub-carrier processing method that Fig. 2 provides for the embodiment of the invention, as shown in Figure 2, the method for present embodiment comprises:

Step 201, select the subcarrier conduct reservation subcarrier corresponding of other user terminal with the data subcarrier at active user terminal; The data subcarrier at said active user terminal is all subcarriers that said active user's terminal distribution arrives, and whole wave bands of the data subcarrier at said active user terminal are used for transmission of data signals;

The embodiment of the invention is primarily aimed at the process that user terminal sends upstream data.With the ofdm system is example, and in a scheduling time, promptly in OFDM symbol, a plurality of user terminals transmit data simultaneously with the mode of frequency division multiplexing, and each user terminal then can be got band segment on the whole frequency as its subcarrier.In one embodiment, suppose in the ofdm system that total sub-carrier number is N, the active user terminal is assigned to K continuous data subcarrier and is used for the signal transmission in certain time slot, and its initial data subcarrier sequence number is l.Suppose that it is X (k) that the active user terminal needs the frequency domain signal transmitted sequence, (k=1,2 ...; N), therefore, this sequence satisfies X (k)=0 (k=1,2; ... l-1, l+K, l+K+1 ...; N), i.e. this user terminal transmission signals on the data subcarrier that is its distribution only, and transmission signals is 0 on the data subcarrier that distributes for this user terminal not belonging to.

Present embodiment selects not belong to the subcarrier for active user's terminal distribution, and promptly the subcarrier of other user terminal is as keeping subcarrier, and the data subcarrier at active user terminal does not change.

Step 202, will be modulated on the said reservation subcarrier with the corresponding peak clipping sequence of said active user's terminal transmission frequency-region signal.

Peak clipping sequence can be expressed as C ^m(k), (k=1,2 ..., N, m=0,1,2 ..., M).In concrete implementation procedure, this peak clipping sequence can be obtained through iterative processing, and wherein subscript m representes iterations.No matter how many iterationses is, peak clipping sequence satisfies C all the time ^m(k)=0 (k=l, l+1 ..., l+K-1), promptly on the data subcarrier that distributes for user terminal, this peak clipping sequence is 0.Therefore, the active user terminal is X (k)+C at the actual sequence of frequency domain transmission ^M(k).Then active user's terminal transmission is to be X (k)+C with time-domain signal ^M(k) signal that obtains behind the inverse fast fourier transform (IFFT).Because the peak clipping sequence on the frequency domain is converted into after the time-domain signal; Peak at the original time-domain signal of active user's terminal transmission also can generate spike; And the spike of the spike of the time-domain signal that peak clipping sequence is corresponding and the original time-domain signal of active user's terminal transmission is reverse; So after the two stack, the peak value of the original time-domain signal of active user's terminal transmission will be cut down, thereby can reduce the peak-to-average force ratio of the ofdm signal that need transmit at the active user terminal.

This shows that the subcarrier ripple that distributes for other user terminal can be counted as the reservation subcarrier corresponding with the data subcarrier at active user terminal.At this moment; Ofdm system can keep on the subcarrier at these; Promptly remove on other user's outside the data subcarrier at active user terminal the subcarrier and modulate peak clipping sequence; And any variation does not take place in the data subcarrier at active user terminal itself, can transmission of data signals on the whole frequency of this data subcarrier, thus make the data subcarrier at active user terminal itself not have the waste problem of transfer resource.This shows that the peak clipping sequence of modulation has no influence for the active user terminal, but can be regarded as interference signal other user terminal in ofdm system.And through effective signal processing means, the energy of the interference signal of introducing for other user terminal is controlled, even thereby the signal to noise ratio when carrying out demodulation process for other user terminal have suitable influence, this influence also can be very little.

Need to prove; The embodiment of the invention not only can be applied to ofdm system, can also be applied to other multicarrier system, the for example multiplexing access of single carrier frequency division (Single Carrier FrequencyDivision Multiple Access; Hereinafter to be referred as: SC-FDMA); Though the peak-to-average force ratio problem of SC-FDMA own is little, (Multiple-Input Multiple-Out-put is hereinafter to be referred as MIMO) technology to have new technology to point out in SC-FDMA, to introduce multiple-input and multiple-output at present; The too high situation of peak-to-average force ratio can appear again in this moment, so the embodiment of the invention is applicable to that simultaneously MIMO SC-FDMA system reduces peak-to-average force ratio.

To sum up can know; The embodiment of the invention through with the subcarrier of other user terminal as the reservation subcarrier corresponding with the data subcarrier at active user terminal; And on this reservation subcarrier, modulate peak clipping sequence, make the total data subcarrier at active user terminal can both be used for transmission of data signals, therefore; When reducing peak-to-average force ratio, can also reduce the waste of transfer resource; And; Because any variation does not take place in the data subcarrier at active user terminal; The subcarrier of other user terminal only is equivalent to introduce controlled noise; Therefore for receiver, need not change to accomplish whole user terminals are carried out the operation of demodulation through the data subcarrier data signals transmitted, thereby can not improve the design complexities of receiver.

Further; In order to reduce the influence that peak clipping sequence brings for other user terminal data signals transmitted as far as possible; The embodiment of the invention is provided with three kinds of judgment condition in the process of obtaining the peak clipping sequence that is used for modulation treatment, through these three kinds of judgment condition are made up neatly; Thereby can reduce the interference that peak clipping sequence introduces for other user terminal effectively, improve systematic function.In view of this, the embodiment of the invention can also comprise: at least a method is carried out the iteration decision process in application of interference energy judgement method, threshold value judgement method and the iterations judgement method, obtains the peak clipping sequence that is used for modulation treatment.

Hence one can see that, and the method that the embodiment of the invention is obtained the peak clipping sequence that is used for modulation treatment can have seven kinds: interfering energy judgement method, threshold value judgement method, iterations judgement method, interfering energy judgement method and threshold value judgement method combines, interfering energy judgement method and iterations judgement method combines, threshold value judgement method and iterations judgement method combines and interfering energy judgement method, threshold value judgement method and iterations judgement method all combine.

In the one embodiment of the invention, application of interference energy judgement method is carried out the iteration decision process, obtains the method for the peak clipping sequence that is used for modulation treatment, can comprise:

According to the sampling point information of the time-domain signal corresponding, obtain first and upgrade sequence with said frequency-region signal; According to the said first renewal sequence, obtain the interference energy value of peak clipping sequence; During less than the interfering energy threshold value, said peak clipping sequence is carried out update processing in said interference energy value; According to the peak clipping sequence after the update processing, obtain the time-domain signal after the update processing; According to the sampling point information of the time-domain signal after the update processing, obtain first after the update processing and upgrade sequence, and upgrade sequence according to first after the update processing, obtain the interference energy value after the update processing;

Repeat said process, when the interference energy value after update processing equals the interfering energy threshold value, with current peak clipping sequence as the peak clipping sequence that is used for modulation treatment.

The embodiment of the invention can also comprise the process of the first renewal sequence being carried out noise reduction process, and this noise reduction process can be windowing process.

The process of with a specific embodiment embodiment of the invention application of interference energy judgement method being obtained peak clipping sequence below describes.

Obtain the flow chart of the peak clipping sequence that is used for modulation treatment among another embodiment of sub-carrier processing method that Fig. 3 provides for the embodiment of the invention; As shown in Figure 3; Obtain the process of the peak clipping sequence that is used for modulation treatment in the present embodiment and used interfering energy judgement method, this method can comprise:

Step 301, peak clipping sequence is carried out initialization process;

Even the peak clipping sequence C during iterations m=0 ^m(k)=0;

Step 302, frequency domain signal transmitted on the data subcarrier at active user terminal is carried out inverse fast fourier transform (IFFT) handle, obtain corresponding time-domain signal, and obtain in this time-domain signal amplitude greater than the sampling point information of peak value threshold value;

In one embodiment, can utilize formula (1):

x ^m(n)＝Q(X(k)+C ^m(k)) (1)

Frequency domain signal transmitted on the data subcarrier at active user terminal is carried out IFFT handle, obtain corresponding time-domain signal.

Wherein, x ^m(n) be the time-domain signal of OFDM symbol.Q is inverse fast fourier transform (IFFT) matrix of N * N dimension, and the element of Q can be expressed with following expression:

$q_{n,k}=\frac{1}{\sqrt{N}}{e}^{j2\mathrm{\πk}\·n/N}(n=\mathrm{1,2},...,N;k=\mathrm{1,2},...,N)$

Can be provided with in advance for the peak value threshold value, can establish this peak value threshold value in the present embodiment is A.Therefore, from x ^m(n) can obtain the sampling point information of amplitude in greater than A.

Step 303, sampling point information is handled, obtained first and upgrade sequence C ' (k);

In one embodiment, can adopt formula (2) that sampled point is carried out information processing:

$C^{\′}\left(k\right)=\mathrm{\μ}\underset{\left|x_n^m\right|>A}{\mathrm{\Σ}}\mathrm{sign}\left({x_n}^m\right)\left(\right|{x_n}^m|-A)q_{\mathrm{row}}^n---\left(2\right)$

C(k)＝0，(k＝l，l+1，...，l+K-1)

Wherein, q _Row ⁿThe n that is Q is capable, and μ is a step parameter.And C ' (k) is set to zero corresponding to the signal on the data subcarrier of active user's data, thereby can not introduce any interference to the data-signal of active user's terminal transmission.Need to prove that the formula here (2) is merely a kind of implementation that obtains the first renewal sequence, and is not limited to aforesaid way.In another embodiment, those skilled in the art can also adopt other to obtain the mode of this first renewal sequence as required, for example also can adopt the mode of peak clipping filtering (clipping and filtering) to obtain.

Step 304, upgrade sequence to said first and carry out noise reduction process, obtain second and upgrade sequence C " (k);

In one embodiment, this noise reduction process can adopt the windowing process form, therefore, can application of formula (3) carry out noise reduction process to the said first renewal sequence:

C″(k)＝C′(k)win(k) (3)

Carry out windowing process and can reduce the interference that this peak clipping sequence introduces for the subcarrier of other user terminal.This window function can be any window function that can reach this purpose, raised cosine window for example, rectangular window, Hamming window, Gaussian window or Blackman window etc.

In another embodiment,, then can establish win (k)=1 if do not carry out windowing process, (k=1 ..., N).

Step 305, obtain interference energy value;

Because each time iteration all can be introduced new interference, therefore need to calculate obtain interference energy value, in one embodiment can application of formula (4) calculate and obtain interfering energy and put:

$E^m=\underset{k=1}{\overset{N}{\mathrm{\Σ}}}{|C^{m-1}\left(k\right)-C^{\′}\left(k\right)\mathrm{win}\left(k\right)|}^2---\left(4\right)$

Need to prove; Formula (4) is merely a kind of computing formula of obtaining interference energy value, and according to different discrimination standards, formula (4) can be arbitrary form; In another embodiment, can also be to calculate initial ofdm signal and the signal x after the m time iterative processing ^mThe formula of the energy of sequence of differences (n).As long as can reflect interference energy value, do not do special qualification.

Step 306, judge that whether this interference energy value is less than the interfering energy threshold value; If less than, then execution in step 307, if equal, then execution in step 308, otherwise execution in step 309;

In order to control the annoyance level that peak clipping sequence is introduced for the subcarrier of other user terminal, can set an interfering energy threshold value in advance, note is made I.

Work as E ^mDuring＜I, this interference energy value then is described within the scope that system can bear, therefore, can be proceeded iterative processing, promptly execution in step 307; If this E ^m=I then explains this interference energy value just in time, and the iteration effect of this moment is also best, promptly is regarded as iterative processing in this case and accomplishes, and works as E ^mDuring＞I, explain that then this interference energy value has surpassed the scope that system can bear, can 308 pairs of peak clipping sequence of execution in step adjust this moment.

Step 307, peak clipping sequence is carried out update processing, and execution in step 302;

In one embodiment, can application of formula (5) carry out update processing to peak clipping sequence, this formula (5) can be C ^m(k)=C ^M-1(k)-C " (k)=C ^M-1(k)-(k) win (k) (5) of C '

Step 308, with current C ^m(k) as the peak clipping sequence that is used for modulation treatment;

Step-size parameter mu in step 309, the adjustment formula (2) begins to carry out from step 303, up to E again ^mTill=the I, and with current C ^m(k) as the peak clipping sequence that is used for modulation treatment.

The interfering energy that present embodiment introduces for other user terminal to peak clipping sequence limits, and in the peak-to-average force ratio of the data-signal that reduces active user's terminal transmission, can effectively control the annoyance level that this peak clipping sequence causes for other user terminal; And, carrying out windowing process through upgrading sequence to first, can realize peak clipping sequence is carried out windowing process, therefore can also further reduce of the interference of this peak clipping sequence, thereby guarantee the overall performance of signal transmitting system other user terminal.

In the one embodiment of the invention, can also use said threshold value judgement method and carry out the iteration decision process, obtain the peak clipping sequence that is used for modulation treatment, comprise:

According to the sampling point information of the time-domain signal corresponding, obtain first and upgrade sequence with said frequency-region signal; Upgrade sequence according to said first, obtain the peak clipping sequence after the update processing; According to the peak clipping sequence after the update processing, obtain the time-domain signal after the update processing; The amplitude inequality of the sampled point in the time-domain signal after said update processing is during less than the peak value threshold value, according to the sampling point information of the time-domain signal after the said update processing, obtains first after the update processing and upgrades sequence;

Repeat said process, when the amplitude of all sampled points is all less than the peak value threshold value in the time-domain signal after update processing, with current peak clipping sequence as the peak clipping sequence that is used for modulation treatment.

The embodiment of the invention is adopting threshold value judgement method to obtain the process of the peak clipping sequence that is used for modulation treatment, also can comprise the process of the first renewal sequence being carried out noise reduction process, and this noise reduction process can be windowing process.

The embodiment of the invention through with the subcarrier of other user terminal as the reservation subcarrier corresponding with the data subcarrier at active user terminal; And on this reservation subcarrier, modulate peak clipping sequence; Make whole wave bands of data subcarrier at active user terminal can both be used for transmission of data signals; Therefore, when reducing peak-to-average force ratio, can also avoid the waste of transfer resource; And; Because any variation does not take place in the data subcarrier at active user terminal; The subcarrier of other user terminal only is equivalent to introduce controlled noise; Therefore for receiver, need not change to accomplish whole user terminals are carried out the operation of demodulation through the data subcarrier data signals transmitted, thereby can not improve the design complexities of receiver.

The process of with a specific embodiment embodiment of the invention application threshold value judgement method being obtained peak clipping sequence below describes.

Obtain the flow chart of the peak clipping sequence that is used for modulation treatment among another embodiment of sub-carrier processing method that Fig. 4 provides for the embodiment of the invention, as shown in Figure 4, the process of obtaining the peak clipping sequence that is used for modulation treatment in the present embodiment can comprise:

Step 401, peak clipping sequence is carried out initialization process;

Even the peak clipping sequence C during iterations m=0 ^m(k)=0;

Step 402, frequency domain signal transmitted on the data subcarrier at active user terminal is carried out IFFT handle, obtain corresponding time-domain signal, and obtain in this time-domain signal amplitude greater than the sampling point information of peak value threshold value;

In one embodiment, can utilize formula (1):

x ^m(n)＝Q(X(k)+C ^m(k)) (1)

Frequency domain signal transmitted on the data subcarrier at active user terminal is carried out IFFT handle, obtain corresponding time-domain signal.

Wherein, x ^m(n) be the time-domain signal of OFDM symbol.Q is the inverse fourier transform matrix of N * N dimension, and the element of Q can be expressed with following expression:

$q_{n,k}=\frac{1}{\sqrt{N}}{e}^{j2\mathrm{\πk}\·n/N}(n=\mathrm{1,2},...,N;k=\mathrm{1,2},...,N)$

Can be provided with in advance for the peak value threshold value, can establish this peak value threshold value in the present embodiment is A.Therefore, from x ^m(n) can obtain the sampling point information of amplitude in greater than A.

Step 403, sampling point information is handled, obtained first and upgrade sequence C ' (k);

In one embodiment, can adopt formula (2) that sampled point is carried out information processing:

$C^{\′}\left(k\right)=\mathrm{\μ}\underset{\left|x_n^m\right|>A}{\mathrm{\Σ}}\mathrm{sign}\left({x_n}^m\right)\left(\right|{x_n}^m|-A)q_{\mathrm{row}}^n---\left(2\right)$

C′(k)＝0，(k＝l，l+1，...，l+K-1)

Wherein, q _Row ⁿThe n that is Q is capable, and μ is a step parameter.And C ' (k) is set to zero corresponding to the signal on the data subcarrier of active user's data, thereby can not introduce any interference to the data-signal of active user's terminal transmission.

Step 404, upgrade sequence to said first and carry out noise reduction process, obtain second and upgrade sequence C " (k);

In one embodiment, this noise reduction process can adopt the windowing process form, therefore, can application of formula (3) carry out noise reduction process to the said first renewal sequence

C″(k)＝C′(k)win(k) (3)

Carry out windowing process and can reduce the interference that this peak clipping sequence introduces for the subcarrier of other user terminal.This window function can be any window function that can reach this purpose, for example raised cosine window, rectangular window, Hamming window, Gaussian window or Blackman window etc.In another embodiment, if do not carry out windowing process, then can establish win (k)=1.

Step 405, peak clipping sequence is carried out update processing;

Always can application of formula (5) carry out update processing at an embodiment to peak clipping sequence:

C ^m(k)＝C ^m-1(k)-C″(k)＝C ^m-1(k)-C′(k)win(k) (5)

Step 406, m=m+1, application of formula (1) is obtained x ^m(n);

Step 407, judge whether x ^m(n) amplitude of all sampled points is all less than the peak value threshold value in, if execution in step 408 then, otherwise execution in step 403;

When the amplitude of all sampled points during all less than peak value threshold value A, then can be regarded as iterative processing and finish, when also having amplitude, then still to proceed iterative processing greater than the sampled point of peak value threshold value A, promptly execution in step 403.

Step 408, with current C ^m(k) as the peak clipping sequence that is used for modulation treatment.

The amplitude of the time-domain signal that present embodiment obtains after to each iterative processing is judged; Through successive iteration within the specific limits, with the amplitude limitation of the pairing time-domain signal of frequency domain signal transmitted on the data subcarrier at active user terminal thus effectively reduce the peak-to-average force ratio of the data-signal of active user's terminal transmission; And, carrying out windowing process through upgrading sequence to first, can realize peak clipping sequence is carried out windowing process, therefore can also further reduce of the interference of this peak clipping sequence, thereby guarantee the overall performance of signal transmitting system other user terminal.

In the one embodiment of the invention, can also use said iterations judgement method and carry out the iteration decision process, obtain the peak clipping sequence that is used for modulation treatment, can comprise:

According to the sampling point information of the time-domain signal corresponding, obtain first and upgrade sequence with said frequency-region signal; Upgrade sequence according to said first, obtain the peak clipping sequence after the update processing; According to the peak clipping sequence after the update processing, obtain the time-domain signal after the update processing; At the iterative processing number of times during,, obtain first after the update processing and upgrade sequence according to the sampling point information of the time-domain signal after the said update processing less than preset iterations;

Repeat said process, when the iterative processing number of times equals preset iterations, with current peak clipping sequence as the peak clipping sequence that is used for modulation treatment.

The embodiment of the invention is adopting iterations judgement method to obtain the process of the peak clipping sequence that is used for modulation treatment, also comprises the process of the first renewal sequence being carried out noise reduction process, and this noise reduction process can be windowing process.

The process of with a specific embodiment embodiment of the invention using iterative number of times judgement method being obtained peak clipping sequence below describes.

The sub-carrier processing method that Fig. 5 provides for the embodiment of the invention also obtains the flow chart of the peak clipping sequence that is used for modulation treatment among embodiment, and as shown in Figure 5, the process of obtaining the peak clipping sequence that is used for modulation treatment in the present embodiment can comprise:

Step 501, peak clipping sequence is carried out initialization process;

Even the peak clipping sequence C during iterations m=0 ^m(k)=0;

Step 502, application of formula (1) are carried out inverse fourier transform to frequency domain signal transmitted on the data subcarrier at active user terminal and are handled, and obtain corresponding time-domain signal, and obtain in this time-domain signal amplitude greater than the sampling point information of peak value threshold value;

Formula (1) can be x ^m(n)=Q (X (k)+C ^m(k))

Wherein, x ^m(n) be the time-domain signal of OFDM symbol.Q is the inverse fourier transform matrix of N * N dimension, and the element of Q can be expressed with following expression:

$q_{n,k}=\frac{1}{\sqrt{N}}{e}^{j2\mathrm{\πk}\·n/N}(n=\mathrm{1,2},...,N;k=\mathrm{1,2},...,N)$

Can be provided with in advance for the peak value threshold value, can establish this peak value threshold value in the present embodiment is A.Therefore, from x ^m(n) can obtain the sampling point information of amplitude in greater than A.

Step 503, application of formula (2) are handled sampling point information, obtain first and upgrade sequence C ' (k); This formula (2) can for: $\begin{array}{c}{C}^{\′}\left(k\right)=\mathrm{\μ}\underset{\left|x_n^m\right|>A}{\mathrm{\Σ}}\mathrm{Sign}\left({x_n}^m\right)\left(\right|{x_n}^m|-A)q_{\mathrm{Row}}^n\\ C^{\′}\left(k\right)=0,(k=l,l+1,...,l+K-1)\end{array}$

Wherein, q _Row ⁿThe n that is Q is capable, and μ is a step parameter.And C ' (k) is set to zero corresponding to the signal on the data subcarrier of active user's data, thereby can not introduce any interference to the data-signal of active user's terminal transmission.

Step 504, application of formula (3) are upgraded sequence to said first and are carried out noise reduction process, obtain second and upgrade sequence C " (k);

In actual process, this noise reduction process can adopt the windowing process form, and therefore, this formula (3) can be C " (k)=(k) win (k) of C '.

Carry out windowing process and can reduce the interference that this peak clipping sequence introduces for the subcarrier of other user terminal.This window function can be any window function that can reach this purpose, for example raised cosine window, rectangular window, Hamming window, Gaussian window or Blackman window etc.In another embodiment, if do not carry out windowing process, then can establish win (k)=1.

Step 505, application of formula (5) are carried out update processing to peak clipping sequence;

This formula (5) can be C ^m(k)=C ^M-1(k)-C " (k)=C ^M-1(k)-(k) win (k) of C '.

Step 506, whether judge current iteration number of times m less than preset iterations, if less than, then execution in step 502, otherwise execution in step 507;

For the control algolithm complexity, preset iterations can be set, for example 5 times; When then the current iteration number of times is less than 5 times, can also proceed iterative processing, promptly execution in step 502; When if the current iteration number of times equals 5 times; Explain that then algorithm complex is higher, need withdraw from iterative operation, promptly execution in step 507.

Step 507, with current C ^m(k) as the peak clipping sequence that is used for modulation treatment.

The iterations of present embodiment after to each iterative processing judged; With the iterations restriction of obtaining peak clipping sequence within the specific limits; Thereby in the peak-to-average force ratio of the data-signal that effectively reduces active user's terminal transmission, reduced the complexity of system-computed; And, carrying out windowing process through upgrading sequence to first, can realize peak clipping sequence is carried out windowing process, therefore can also further reduce of the interference of this peak clipping sequence, thereby guarantee the overall performance of signal transmitting system other user terminal.

In the one embodiment of the invention, can the application of interference energy judgement method and threshold value judgement method carry out the iteration decision process, obtain the peak clipping sequence that is used for modulation treatment, comprising:

According to the sampling point information of the time-domain signal corresponding, obtain first and upgrade sequence with said frequency-region signal; According to the said first renewal sequence, obtain the interference energy value of peak clipping sequence; During less than the interfering energy threshold value, said peak clipping sequence is carried out update processing in said interference energy value; According to the peak clipping sequence after the update processing, obtain the time-domain signal after the update processing; The amplitude inequality of the sampled point in the time-domain signal after said update processing is during less than the peak value threshold value, according to the sampling point information of the time-domain signal after the said update processing, obtains first after the update processing and upgrades sequence; And upgrade sequence according to first after the update processing, obtain the interference energy value after the update processing;

Repeat said process; The amplitude of the sampled point in the time-domain signal after said update processing is during all less than the peak value threshold value; When perhaps the interference energy value after the update processing equals the interfering energy threshold value, with current peak clipping sequence as the peak clipping sequence that is used for modulation treatment.

The embodiment of the invention is adopting interfering energy judgement method and threshold value judgement method to obtain the process of the peak clipping sequence that is used for modulation treatment, also can comprise the process of the first renewal sequence being carried out noise reduction process, and this noise reduction process can be windowing process.

With a specific embodiment embodiment of the invention application of interference energy judgement method process that peak clipping sequence is obtained in combination with threshold value judgement method is described below.

The sub-carrier processing method that Fig. 6 provides for the embodiment of the invention obtains the flow chart of the peak clipping sequence that is used for modulation treatment again among another embodiment, and as shown in Figure 6, the process of obtaining the peak clipping sequence that is used for modulation treatment in the present embodiment can comprise:

Step 601, peak clipping sequence is carried out initialization process;

Even the peak clipping sequence C during iterations m=0 ^m(k)=0;

Step 602, application of formula (1) are carried out inverse fourier transform to frequency domain signal transmitted on the data subcarrier at active user terminal and are handled, and obtain corresponding time-domain signal, and obtain in this time-domain signal amplitude greater than the sampling point information of peak value threshold value;

Formula (1) can be x ^m(n)=Q (X (k)+C ^m(k))

Wherein, x ^m(n) be the time-domain signal of OFDM symbol.Q is the inverse fourier transform matrix of N * N dimension, and the element of Q can be expressed with following expression:

$q_{n,k}=\frac{1}{\sqrt{N}}{e}^{j2\mathrm{\πk}\·n/N}(n=\mathrm{1,2},...,N;k=\mathrm{1,2},...,N)$

Can be provided with in advance for the peak value threshold value, can establish this peak value threshold value in the present embodiment is A.Therefore, from x ^m(n) can obtain the sampling point information of amplitude in greater than A.

Step 603, application of formula (2) are handled sampling point information, obtain first and upgrade sequence C ' (k); This formula (2) can for: $\begin{array}{c}{C}^{\′}\left(k\right)=\mathrm{\μ}\underset{\left|x_n^m\right|>A}{\mathrm{\Σ}}\mathrm{Sign}\left({x_n}^m\right)\left(\right|{x_n}^m|-A)q_{\mathrm{Row}}^n\\ C^{\′}\left(k\right)=0,(k=l,l+1,...,l+K-1)\end{array}$

Wherein, q _Row ⁿThe n that is Q is capable, and μ is a step parameter.And C ' (k) is set to zero corresponding to the signal on the data subcarrier of active user's data, thereby can not introduce any interference to the data-signal of active user's terminal transmission.

Step 604, application of formula (3) are upgraded sequence to said first and are carried out noise reduction process, obtain second and upgrade sequence C " (k);

In actual process, this noise reduction process can adopt the windowing process form, and therefore, this formula (3) can be C " (k)=(k) win (k) of C '.

Carry out windowing process and can reduce the interference that this peak clipping sequence introduces for the subcarrier of other user terminal.This window function can be any window function that can reach this purpose, for example raised cosine window, rectangular window, Hamming window, Gaussian window or Blackman window etc.In another embodiment, if do not carry out windowing process, then can establish win (k)=1.

Step 605, application of formula (4) are obtained interference energy value;

Because each time iteration all can be introduced new interference, therefore can application of formula (4) calculate and obtain interference energy value, this formula (4) can for: $E^m=\underset{k=1}{\overset{N}{\mathrm{\Σ}}}{|C^{m-1}\left(k\right)-C^{\′}\left(k\right)\mathrm{Win}\left(k\right)|}^2.$

Need to prove that this formula (4) is merely a kind of computing formula of obtaining interference energy value, according to different discrimination standards, this formula (4) can be arbitrary form, as long as can reflect interference energy value.

Step 606, whether judge this interference energy value less than the interfering energy threshold value, if less than, then execution in step 607, if equal, then execution in step 610, otherwise execution in step 611;

In order to control the annoyance level that peak clipping sequence is introduced for the subcarrier of other user terminal, can set an interfering energy threshold value in advance, note is made I.

Work as E ^mDuring＜I, this interference energy value then is described within the scope that system can bear, therefore, can be proceeded iterative processing, promptly execution in step 607; If this E ^m=I then explains this interference energy value just in time, and the iteration effect of this moment is also best, promptly is regarded as iterative processing in this case and accomplishes, and execution in step 610 is worked as E ^mDuring＞I, explain that then this interference energy value has surpassed the scope that system can bear, can 611 pairs of peak clipping sequence of execution in step adjust this moment.

Step 607, application of formula (5) are carried out update processing, m=m+1 to peak clipping sequence;

This formula (5) can be C ^m(k)=C ^M-1(k)-C " (k)=C ^M-1(k)-(k) win (k) of C '.

Step 608, application of formula (1) are calculated the time-domain signal x after the update processing ^m(n);

Step 609, judge the time-domain signal x after this update processing ^mWhether the amplitude of the sampled point (n) all less than the peak value threshold value, if all less than, then execution in step 610, otherwise execution in step 603;

Step 610, with current C ^m(k) as the peak clipping sequence that is used for modulation treatment;

Step-size parameter mu in step 611, the adjustment formula (2) begins to carry out from step 603, up to E again ^mTill=the I, and with current C ^m(k) as the peak clipping sequence that is used for modulation treatment.

Present embodiment is by adjudicating interfering energy the combination of method and threshold value judgement method; The interfering energy of introducing for other user terminal to peak clipping sequence limits; Whether the amplitude that also need judge the time-domain signal that obtains behind the successive iteration simultaneously is less than the peak value threshold value; Can finishing iteration handle when having a judgment condition to satisfy in these two judgment condition; Obtain the peak clipping sequence that is used for modulation treatment; Thereby in the peak-to-average force ratio of the data-signal that reduces active user's terminal transmission, can effectively control the annoyance level that this peak clipping sequence causes for other user terminal; And, carrying out windowing process by upgrading sequence to first, can realize peak clipping sequence is carried out windowing process, therefore can also further reduce of the interference of this peak clipping sequence, thereby guarantee the overall performance of signal transmitting system other user terminal.

In the one embodiment of the invention, application of interference energy judgement method and iterations judgement method are carried out the iteration decision process, obtain the peak clipping sequence that is used for modulation treatment, can comprise:

According to the sampling point information of the time-domain signal corresponding, obtain first and upgrade sequence with said frequency-region signal; According to the said first renewal sequence, obtain the interference energy value of peak clipping sequence; During less than the interfering energy threshold value, said peak clipping sequence is carried out update processing in said interference energy value; According to the peak clipping sequence after the update processing, obtain the time-domain signal after the update processing; At iterations during,, obtain first after the update processing and upgrade sequence according to the sampling point information of the time-domain signal after the said update processing less than preset iterations; And upgrade sequence according to first after the update processing, obtain the interference energy value after the update processing;

Repeat said process, up to iterations during less than preset iterations, when perhaps the interference energy value after the update processing equals the interfering energy threshold value, with current peak clipping sequence as the peak clipping sequence that is used for modulation treatment.

The embodiment of the invention is adopting interfering energy judgement method and iterations judgement method to obtain the process of the peak clipping sequence that is used for modulation treatment, also can comprise the process of the first renewal sequence being carried out noise reduction process, and this noise reduction process can be windowing process.

With a specific embodiment embodiment of the invention application of interference energy judgement method process that peak clipping sequence is obtained in combination with iterations judgement method is described below.

The sub-carrier processing method that Fig. 7 provides for the embodiment of the invention obtains the flow chart of the peak clipping sequence that is used for modulation treatment again among another embodiment, and as shown in Figure 7, the process of obtaining the peak clipping sequence that is used for modulation treatment in the present embodiment can comprise:

Step 701, peak clipping sequence is carried out initialization process;

Even the peak clipping sequence C during iterations m=0 ^m(k)=0;

Step 702, application of formula (1) are carried out inverse fourier transform to frequency domain signal transmitted on the data subcarrier at active user terminal and are handled, and obtain corresponding time-domain signal, and obtain in this time-domain signal amplitude greater than the sampling point information of peak value threshold value;

Formula (1) can be x ^m(n)=Q (X (k)+C ^m(k))

Wherein, x ^m(n) be the time-domain signal of OFDM symbol.Q is the inverse fourier transform matrix of N * N dimension, and the element of Q can be expressed with following expression:

$q_{n,k}=\frac{1}{\sqrt{N}}{e}^{j2\mathrm{\πk}\·n/N}(n=\mathrm{1,2},...,N;k=\mathrm{1,2},...,N)$

Can be provided with in advance for the peak value threshold value, can establish this peak value threshold value in the present embodiment is A.Therefore, from x ^m(n) can obtain the sampling point information of amplitude in greater than A.

Step 703, application of formula (2) are handled sampling point information, obtain first and upgrade sequence C ' (k); This formula (2) can for: $\begin{array}{c}{C}^{\′}\left(k\right)=\mathrm{\μ}\underset{\left|x_n^m\right|>A}{\mathrm{\Σ}}\mathrm{Sign}\left({x_n}^m\right)\left(\right|{x_n}^m|-A)q_{\mathrm{Row}}^n\\ C^{\′}\left(k\right)=0,(k=l,l+1,...,l+K-1)\end{array}$

Wherein, q _Row ⁿThe n that is Q is capable, and μ is a step parameter.And C ' (k) is set to zero corresponding to the signal on the data subcarrier of active user's data, thereby can not introduce any interference to the data-signal of active user's terminal transmission.

Step 704, application of formula (3) are upgraded sequence to said first and are carried out noise reduction process, obtain second and upgrade sequence C " (k);

In actual process, this noise reduction process can adopt the windowing process form, and therefore, this formula (3) can be C " (k)=(k) win (k) of C '.

Carry out windowing process and can reduce the interference that this peak clipping sequence introduces for the subcarrier of other user terminal.This window function can be any window function that can reach this purpose, for example raised cosine window, rectangular window, Hamming window, Gaussian window or Blackman window etc.In another embodiment, if do not carry out windowing process, then can establish win (k)=1.

Step 705, application of formula (4) are obtained interference energy value;

Because each time iteration all can be introduced new interference, therefore can application of formula (4) calculate and obtain interference energy value, this formula (4) can for: $E^m=\underset{k=1}{\overset{N}{\mathrm{\Σ}}}{|C^{m-1}\left(k\right)-C^{\′}\left(k\right)\mathrm{Win}\left(k\right)|}^2.$

Need to prove that this formula (4) is merely a kind of computing formula of obtaining interference energy value, according to different discrimination standards, this formula (4) can be arbitrary form, as long as can reflect interference energy value.

Step 706, whether judge this interference energy value less than the interfering energy threshold value, if less than, then execution in step 707, if equal, then execution in step 710, otherwise execution in step 711;

In order to control the annoyance level that peak clipping sequence is introduced for the subcarrier of other user terminal, can set an interfering energy threshold value in advance, note is made I.

Work as E ^mDuring＜I, this interference energy value then is described within the scope that system can bear, therefore, can be proceeded iterative processing, promptly execution in step 707; If this E ^m=I then explains this interference energy value just in time, and the iteration effect of this moment is also best, promptly is regarded as iterative processing in this case and accomplishes, and execution in step 710 is worked as E ^mDuring＞I, explain that then this interference energy value has surpassed the scope that system can bear, can 711 pairs of peak clipping sequence of execution in step adjust this moment.

Step 707, application of formula (5) are carried out update processing, m=m+1 to peak clipping sequence;

This formula (5) can be C ^m(k)=C ^M-1(k)-C " (k)=C ^M-1(k)-(k) win (k) of C '.

Step 708, application of formula (1) are calculated the time-domain signal x after the update processing ^m(n)

Step 709, whether judge iterations m less than preset iterations, if less than, then execution in step 710, otherwise execution in step 603;

Step 710, with current C ^m(k) as the peak clipping sequence that is used for modulation treatment;

Step-size parameter mu in step 711, the adjustment formula (2) begins to carry out from step 703, up to E again ^mTill=the I, and with current C ^m(k) as the peak clipping sequence that is used for modulation treatment.

Present embodiment combines through interfering energy being adjudicated method and iterations judgement method; The interfering energy of introducing for other user terminal to peak clipping sequence limits; Need judge also that simultaneously whether iterations behind the successive iteration is less than preset iterations; Can finishing iteration handle when having a judgment condition to satisfy in these two judgment condition, obtain the peak clipping sequence that is used for modulation treatment, thereby in the peak-to-average force ratio of the data-signal that reduces active user's terminal transmission; Can effectively control the annoyance level that this peak clipping sequence causes for other user terminal, and reduce the complexity of system-computed; And, carrying out windowing process through upgrading sequence to first, can realize peak clipping sequence is carried out windowing process, therefore can also further reduce of the interference of this peak clipping sequence, thereby guarantee the overall performance of signal transmitting system other user terminal.

In the one embodiment of the invention, use threshold value judgement method and iterations judgement method and carry out the iteration decision process, obtain the peak clipping sequence that is used for modulation treatment, can comprise:

According to the sampling point information of the time-domain signal corresponding, obtain first and upgrade sequence with said frequency-region signal; Upgrade sequence according to said first, obtain the peak clipping sequence after the update processing; According to the peak clipping sequence after the update processing, obtain the time-domain signal after the update processing; The amplitude inequality of the sampled point in the time-domain signal after said update processing is less than peak value threshold value and iterations during less than preset iterations; According to the sampling point information of the time-domain signal after the said update processing, obtain first after the update processing and upgrade sequence;

Repeat said process, when the amplitude of all sampled points all equals preset iterations less than peak value threshold value or iterations in the time-domain signal after update processing, with current peak clipping sequence as the peak clipping sequence that is used for modulation treatment.

The embodiment of the invention is adopting threshold value threshold judgement method and iterations judgement method to obtain the process of the peak clipping sequence that is used for modulation treatment, also can comprise the process of the first renewal sequence being carried out noise reduction process, and this noise reduction process can be windowing process.

With a specific embodiment embodiment of the invention being used the threshold value judgement method process that peak clipping sequence is obtained in combination with iterations judgement method below describes.

Fig. 8 goes back the flow chart that obtains the peak clipping sequence that is used for modulation treatment among the embodiment again for the sub-carrier processing method that the embodiment of the invention provides, and as shown in Figure 8, the process of obtaining the peak clipping sequence that is used for modulation treatment in the present embodiment can comprise:

Step 801, peak clipping sequence is carried out initialization process;

Even the peak clipping sequence C during iterations m=0 ^m(k)=0;

Step 802, application of formula (1) are carried out inverse fourier transform to frequency domain signal transmitted on the data subcarrier at active user terminal and are handled, and obtain corresponding time-domain signal, and obtain in this time-domain signal amplitude greater than the sampling point information of peak value threshold value;

Formula (1) can be x ^m(n)=Q (X (k)+C ^m(k))

Wherein, x ^m(n) be the time-domain signal of OFDM symbol.Q is the inverse fourier transform matrix of N * N dimension, and the element of Q can be expressed with following expression:

$q_{n,k}=\frac{1}{\sqrt{N}}{e}^{j2\mathrm{\πk}\·n/N}(n=\mathrm{1,2},...,N;k=\mathrm{1,2},...,N)$

Can be provided with in advance for the peak value threshold value, can establish this peak value threshold value in the present embodiment is A.Therefore, from x ^m(n) can obtain the sampling point information of amplitude in greater than A.

Step 803, application of formula (2) are handled sampling point information, obtain first and upgrade sequence C ' (k); This formula (2) can for: $\begin{array}{c}{C}^{\′}\left(k\right)=\mathrm{\μ}\underset{\left|x_n^m\right|>A}{\mathrm{\Σ}}\mathrm{Sign}\left({x_n}^m\right)\left(\right|{x_n}^m|-A)q_{\mathrm{Row}}^n\\ C^{\′}\left(k\right)=0,(k=l,l+1,...,l+K-1)\end{array}$

Wherein, q _Row ⁿThe n that is Q is capable, and μ is a step parameter.And C ' (k) is set to zero corresponding to the signal on the data subcarrier of active user's data, thereby can not introduce any interference to the data-signal of active user's terminal transmission.

Step 804, application of formula (3) are upgraded sequence to said first and are carried out noise reduction process, obtain second and upgrade sequence C " (k);

In actual process, this noise reduction process can adopt the windowing process form, and therefore, this formula (3) can be C " (k)=(k) win (k) of C '.

Carry out windowing process and can reduce the interference that this peak clipping sequence introduces for the subcarrier of other user terminal.This window function can be any window function that can reach this purpose, for example raised cosine window, rectangular window, Hamming window, Gaussian window or Blackman window etc.In another embodiment, if do not carry out windowing process, then can establish win (k)=1.

Step 805, application of formula (5) are carried out update processing to peak clipping sequence;

This formula (5) can be C ^m(k)=C ^M-1(k)-C " (k)=C ^M-1(k)--C ' is win (k) (k).

Step 806, m=m+1, application of formula (1) is obtained x ^m(n);

Step 807, judge whether x ^m(n) amplitude of all sampled points is all less than the peak value threshold value in, if execution in step 809 then, otherwise execution in step 808;

When the amplitude of all sampled points during all less than peak value threshold value A, then can be regarded as iterative processing and finish, when also having amplitude, then still to proceed iterative processing greater than the sampled point of peak value threshold value A, promptly execution in step 808.

Step 808, judge whether iterations m equals preset iterations, if then execution in step 809, otherwise execution in step 803;

In order to reduce the complexity of system-computed, can preset the higher limit of an iterations, when reaching this iterations, can stop iterative processing, obtain the peak clipping sequence of active user's modulation treatment.

Step 809, with current C ^m(k) as the peak clipping sequence that is used for modulation treatment.

Present embodiment is adjudicated method and the combination of iterations judgement method with threshold value; Amplitude to the time-domain signal that obtains after each iterative processing is judged; By successive iteration within the specific limits with the amplitude limitation of the pairing time-domain signal of frequency domain signal transmitted on the data subcarrier at active user terminal; And also introduced the iterations higher limit simultaneously; Thereby, also greatly reduce the complexity of system-computed at the peak-to-average force ratio of the data-signal that effectively reduces active user's terminal transmission; And, carrying out windowing process by upgrading sequence to first, can realize peak clipping sequence is carried out windowing process, therefore can also further reduce of the interference of this peak clipping sequence, thereby guarantee the overall performance of signal transmitting system other user terminal.

In the one embodiment of the invention, application of interference energy judgement method, threshold value judgement method and iterations judgement method are carried out the iteration decision process, obtain the peak clipping sequence that is used for modulation treatment, can comprise:

According to the sampling point information of the time-domain signal corresponding, obtain first and upgrade sequence with said frequency-region signal; According to the said first renewal sequence, obtain the interference energy value of peak clipping sequence; During less than the interfering energy threshold value, said peak clipping sequence is carried out update processing in said interference energy value; According to the peak clipping sequence after the update processing, obtain the time-domain signal after the update processing; The amplitude inequality of the sampled point in the time-domain signal after said update processing is less than peak value threshold value and iterations during less than preset iterations; According to the sampling point information of the time-domain signal after the said update processing, obtain first after the update processing and upgrade sequence; And upgrade sequence according to first after the update processing, obtain the interference energy value after the update processing;

Repeat said process; When the amplitude that the interference energy value after update processing equals the sampled point in the time-domain signal after interfering energy threshold value or the said update processing all equals preset iterations less than peak value threshold value or iterations, with current peak clipping sequence as the peak clipping sequence that is used for modulation treatment.

Present embodiment is that above-mentioned interfering energy judgement method, threshold value judgement method and iterations judgement method are combined; Adopt three layers of judgment condition that iterative processing is controlled; Thereby when any judgment condition of these three layers of judgment condition satisfies, all can obtain the peak clipping sequence that is used for modulation treatment accordingly.In concrete implementation procedure, it is similar to the above embodiments that present embodiment obtains the process of the peak clipping sequence that is used for modulation treatment, repeats no more.

The structural representation of the embodiment of subcarrier processing unit that Fig. 9 provides for the embodiment of the invention, as shown in Figure 9, the device of present embodiment comprises: select module 11 and modulation module 12,

Select module 11 to be used to select the subcarrier conduct reservation subcarrier corresponding of other user terminal with the data subcarrier at active user terminal; The data subcarrier at said active user terminal is all subcarriers that said active user's terminal distribution arrives, and whole wave bands of the data subcarrier at said active user terminal are used for transmission of data signals;

Specifically, in one embodiment, be example with the ofdm system; In a scheduling time; Promptly in OFDM symbol, a plurality of user terminals transmit data simultaneously with the mode of frequency division multiplexing, and each user terminal then can be got band segment on the whole frequency as its data subcarrier.Select module 11 to select the subcarrier conduct reservation subcarrier corresponding of other user terminal with the data subcarrier at active user terminal.

Modulation module 12 is used for the peak clipping sequence corresponding with the frequency-region signal of said active user's terminal transmission is modulated at said reservation subcarrier.

With the ofdm system is example, and in a scheduling time, promptly in OFDM symbol, a plurality of user terminals transmit data simultaneously with the mode of frequency division multiplexing, and each user terminal then can be got band segment on the whole frequency as its data subcarrier.Suppose in the ofdm system that total data subcarrier number is N, the active user terminal is assigned to K continuous data subcarrier and is used for the signal transmission in certain time slot, and its initial data subcarrier sequence number is l.Suppose that it is X (k) that the active user terminal needs the frequency domain signal transmitted sequence, (k=1,2 ...; N), therefore, this sequence satisfies X (k)=0 (k=1,2; ... l-1, l+K, l+K+1 ...; N), i.e. this user terminal transmission signals on the data subcarrier that is its distribution only, and transmission signals is 0 on the data subcarrier that distributes for this user terminal not belonging to.

Selection module 11 in the present embodiment selects not belong to the data subcarrier for active user's terminal distribution, and promptly the subcarrier of other user terminal is as keeping subcarrier, and any variation does not take place the data subcarrier at active user terminal.

Peak clipping sequence can be expressed as C ^m(k), (k=1,2 ..., N, m=0,1,2 ..., M).In concrete implementation procedure, this peak clipping sequence can be obtained through iterative processing, and wherein subscript m representes iterations.No matter how many iterationses is, peak clipping sequence satisfies C all the time ^m(k)=0 (k=l, l+1 ..., l+K-1), promptly on the data subcarrier that distributes for user terminal, this peak clipping sequence is 0.Therefore, the active user terminal is X (k)+C at the actual sequence of frequency domain transmission ^M(k).Then active user's terminal transmission is to be X (k)+C with time-domain signal ^M(k) signal that obtains behind the inverse fourier transform.Because the peak clipping sequence on the frequency domain is converted into after the time-domain signal; Peak at the original time-domain signal of active user's terminal transmission also can generate spike; And the spike of the spike of the time-domain signal that peak clipping sequence is corresponding and the original time-domain signal of active user's terminal transmission is reverse; So after the two stack, the peak value of the original time-domain signal of active user's terminal transmission will be cut down, thereby can reduce the peak-to-average force ratio of the ofdm signal that need transmit at the active user terminal.

This shows that the subcarrier that distributes for other user terminal can be counted as the reservation subcarrier corresponding with the data subcarrier at active user terminal.At this moment; Modulation module 12 can keep on other data subcarrier outside the data subcarrier of promptly removing the active user terminal on the subcarrier at these modulates peak clipping sequence; And any variation does not take place in the data subcarrier at active user terminal itself; Can transmission of data signals on the whole frequency of this data subcarrier, thus make the data subcarrier at active user terminal itself not have the waste problem of transfer resource.This shows that the peak clipping sequence of modulation has no influence for the active user terminal, but for other user terminal, can be regarded as interference signal.Through effective signal processing means, the energy of the interference signal of introducing for other user terminal is controlled, even thereby the signal to noise ratio when carrying out demodulation process for other user terminal have suitable influence, this influence also can be very little.

Need to prove; The device of the embodiment of the invention not only can be applied to ofdm system, can also be applied to other multicarrier system, for example the SC-FDMA system; Though the peak-to-average force ratio problem of SC-FDMA own is little; But have new technology to point out in SC-FDMA, to introduce the MIMO technology at present, the too high situation of peak-to-average force ratio can appear again in this moment, so the embodiment of the invention is applicable to that simultaneously the MIMOSC-FDMA system reduces peak-to-average force ratio.

To sum up can know; The embodiment of the invention through select module with the subcarrier of other user terminal as the reservation subcarrier corresponding with the data subcarrier at active user terminal; And the application of modulation module modulates peak clipping sequence on this reservation subcarrier, makes whole wave bands of data subcarrier at active user terminal can both be used for transmission of data signals, therefore; When reducing peak-to-average force ratio, can also avoid the waste of transfer resource; And; Because any variation does not take place in the data subcarrier at active user terminal; The subcarrier of other user terminal only is equivalent to introduce controlled noise; Therefore for receiver, need not change to accomplish whole user terminals are carried out the operation of demodulation through the data subcarrier data signals transmitted, thereby can not improve the design complexities of receiver.

The structural representation of another embodiment of subcarrier processing unit that Figure 10 provides for the embodiment of the invention; Shown in figure 10; The device of present embodiment is on last basis with embodiment; Further comprise: acquisition module 13, this acquisition module 13 are used for application of interference energy judgement method, threshold value judgement method and at least a method of iterations judgement method and carry out the iteration decision process, obtain said peak clipping sequence.

Further, this acquisition module 13 comprises: first acquiring unit 131, second acquisition unit 132, the 3rd acquiring unit 133, the 4th acquiring unit 134, the 5th acquiring unit 135, the 6th acquiring unit 136, the 7th acquiring unit 137 and selected cell 138.Wherein first acquiring unit 131 is used for obtaining said peak clipping sequence according to said interfering energy judgement method; Second acquisition unit 132 is used for obtaining said peak clipping sequence according to said threshold value judgement method; The 3rd acquiring unit 133 is used for obtaining said peak clipping sequence according to said iterations judgement method; The 4th acquiring unit 134 is used for obtaining said peak clipping sequence according to said interfering energy judgement method and said threshold value judgement method; The 5th acquiring unit 135 is used for obtaining said peak clipping sequence according to said interfering energy judgement method and said iterations judgement method; The 6th acquiring unit 136 is used for obtaining said peak clipping sequence according to said threshold value judgement method and said iterations judgement method; The 7th acquiring unit 137 is used for obtaining said peak clipping sequence according to said interfering energy judgement method, said threshold value judgement method and said iterations judgement method; Selected cell 138 is used for according to external control signal said first acquiring unit to the, seven acquiring units being selected to handle.

In the device of present embodiment; This selected cell 138 can be according to external control signal; The mode of the peak clipping sequence that is used for modulation treatment is obtained in selection; The method of obtaining the peak clipping sequence that is used for modulation treatment of first acquiring unit 131, second acquisition unit 132, the 3rd acquiring unit 133, the 4th acquiring unit 134, the 5th acquiring unit 135, the 6th acquiring unit 136, the 7th acquiring unit 137 is corresponding one by one with said method embodiment, repeats no more.Present embodiment is that selected cell provides the mode of wherein adjudicating through seven acquiring units; Thereby make that the process of obtaining the peak clipping sequence that is used for modulation treatment is comparatively flexible; And the peak clipping sequence of obtaining can take into full account the interference of introducing into other user terminal; Thereby in the peak-to-average force ratio that reduces active user's terminal transmission signal, guaranteed the reliability of system.

The structural representation of the embodiment of multicarrier system that Figure 11 provides for the embodiment of the invention; Shown in figure 11; This system comprises: subcarrier processing unit 10 and receiving system 20; Subcarrier processing unit 10 is used to select the subcarrier conduct reservation subcarrier corresponding with the data subcarrier at active user terminal of other user terminal; The data subcarrier at said active user terminal is all subcarriers that said active user's terminal distribution arrives, and whole wave bands of the data subcarrier at said active user terminal are used for transmission of data signals; The peak clipping sequence corresponding with the frequency-region signal of said active user's terminal transmission is modulated on the said reservation subcarrier; Receiving system 20 is used to receive said frequency-region signal, and said frequency-region signal is handled.

In another embodiment, subcarrier processing unit 10 also is used for, and at least a method is carried out the iteration decision process in application of interference energy judgement method, threshold value judgement method and the iterations judgement method, obtains said peak clipping sequence.

Need to prove that the 26S Proteasome Structure and Function of subcarrier processing unit in one embodiment can be of the embodiment that Fig. 9 provides, in another embodiment also can be of the embodiment that Fig. 9 and Figure 10 provide, repeat no more at this.

The embodiment of the invention through with the subcarrier of other user terminal as the reservation subcarrier corresponding with the data subcarrier at active user terminal; And on this reservation subcarrier, modulate peak clipping sequence; Make whole wave bands of data subcarrier at active user terminal can both be used for transmission of data signals; Therefore, when reducing peak-to-average force ratio, can also avoid the waste of transfer resource; And; Because any variation does not take place in the data subcarrier at active user terminal; The subcarrier of other user terminal only is equivalent to introduce controlled noise; Therefore for receiver, need not change to accomplish whole user terminals are carried out the operation of demodulation through the data subcarrier data signals transmitted, thereby can not improve the design complexities of receiver.

Through the description of above execution mode, those skilled in the art can be well understood to the present invention and can realize by the mode that software adds essential hardware platform, can certainly all implement through hardware.Based on such understanding; All or part of can the coming out that technical scheme of the present invention contributes to background technology with the embodied of software product; This computer software product can be stored in the storage medium, like ROM/RAM, magnetic disc, CD etc., comprises that some instructions are with so that a computer equipment (can be a personal computer; Server, the perhaps network equipment etc.) carry out the described method of some part of each embodiment of the present invention or embodiment.

What should explain at last is: above embodiment is only in order to technical scheme of the present invention to be described but not limit it; Although the present invention has been carried out detailed explanation with reference to preferred embodiment; Those of ordinary skill in the art is to be understood that: it still can make amendment or be equal to replacement technical scheme of the present invention, also can not make amended technical scheme break away from the spirit and the scope of technical scheme of the present invention and these are revised or be equal to replacement.

Claims (12)

1. a sub-carrier processing method is characterized in that, comprising:

Select the subcarrier conduct reservation subcarrier corresponding of other user terminal with the data subcarrier at active user terminal; The data subcarrier at said active user terminal is all subcarriers that said active user's terminal distribution arrives, and whole wave bands of the data subcarrier at said active user terminal are used for transmission of data signals;

The peak clipping sequence corresponding with the frequency-region signal of said active user's terminal transmission is modulated on the said reservation subcarrier.

2. sub-carrier processing method according to claim 1 is characterized in that, also comprises:

At least a method is carried out the iteration decision process in application of interference energy judgement method, threshold value judgement method and the iterations judgement method, obtains said peak clipping sequence.

3. sub-carrier processing method according to claim 2 is characterized in that, uses said interfering energy judgement method and carries out the iteration decision process, obtains said peak clipping sequence, comprising:

According to the sampling point information of the time-domain signal corresponding, obtain first and upgrade sequence with said frequency-region signal; According to the said first renewal sequence, obtain the interference energy value of peak clipping sequence; During less than the interfering energy threshold value, said peak clipping sequence is carried out update processing in said interference energy value; According to the peak clipping sequence after the update processing, obtain the time-domain signal after the update processing; According to the sampling point information of the time-domain signal after the update processing, obtain first after the update processing and upgrade sequence, and upgrade sequence according to first after the update processing, obtain the interference energy value after the update processing;

Repeat said process, when the interference energy value after update processing equals the interfering energy threshold value, with current peak clipping sequence as the peak clipping sequence that is used for modulation treatment.

4. sub-carrier processing method according to claim 2 is characterized in that, uses said threshold value judgement method and carries out the iteration decision process, obtains said peak clipping sequence, comprising:

According to the sampling point information of the time-domain signal corresponding, obtain first and upgrade sequence with said frequency-region signal; Upgrade sequence according to said first, obtain the peak clipping sequence after the update processing; According to the peak clipping sequence after the update processing, obtain the time-domain signal after the update processing; The amplitude inequality of the sampled point in the time-domain signal after said update processing is during less than the peak value threshold value, according to the sampling point information of the time-domain signal after the said update processing, obtains first after the update processing and upgrades sequence;

Repeat said process, when the amplitude of all sampled points is all less than the peak value threshold value in the time-domain signal after update processing, with current peak clipping sequence as the peak clipping sequence that is used for modulation treatment.

5. sub-carrier processing method according to claim 2 is characterized in that, uses said iterations judgement method and carries out the iteration decision process, obtains said peak clipping sequence, comprising:

According to the sampling point information of the time-domain signal corresponding, obtain first and upgrade sequence with said frequency-region signal; Upgrade sequence according to said first, obtain the peak clipping sequence after the update processing; According to the peak clipping sequence after the update processing, obtain the time-domain signal after the update processing; At the iterative processing number of times during,, obtain first after the update processing and upgrade sequence according to the sampling point information of the time-domain signal after the said update processing less than preset iterations;

Repeat said process, when the iterative processing number of times equals preset iterations, with current peak clipping sequence as the peak clipping sequence that is used for modulation treatment.

6. according to the described sub-carrier processing method of arbitrary claim in the claim 3～5, it is characterized in that, comprise that also upgrading sequence to said first carries out noise reduction process.

7. sub-carrier processing method according to claim 6 is characterized in that, said noise reduction process is windowing process.

8. a sub-carrier processing unit is characterized in that, comprising:

Select module; Be used to select the subcarrier conduct reservation subcarrier corresponding of other user terminal with the data subcarrier at active user terminal; The data subcarrier at said active user terminal is all subcarriers that said active user's terminal distribution arrives, and whole wave bands of the data subcarrier at said active user terminal are used for transmission of data signals;

Modulation module is used for the peak clipping sequence corresponding with the frequency-region signal of said active user's terminal transmission is modulated at said reservation subcarrier.

9. subcarrier processing unit according to claim 8 is characterized in that, also comprises:

Acquisition module is used for application of interference energy judgement method, threshold value judgement method and at least a method of iterations judgement method and carries out the iteration decision process, obtains said peak clipping sequence.

10. subcarrier processing unit according to claim 9 is characterized in that, said acquisition module comprises:

First acquiring unit is used for obtaining said peak clipping sequence according to said interfering energy judgement method;

Second acquisition unit is used for obtaining said peak clipping sequence according to said threshold value judgement method;

The 3rd acquiring unit is used for obtaining said peak clipping sequence according to said iterations judgement method;

The 4th acquiring unit is used for obtaining said peak clipping sequence according to said interfering energy judgement method and said threshold value judgement method;

The 5th acquiring unit is used for obtaining said peak clipping sequence according to said interfering energy judgement method and said iterations judgement method;

The 6th acquiring unit is used for obtaining said peak clipping sequence according to said threshold value judgement method and said iterations judgement method;

The 7th acquiring unit is used for obtaining said peak clipping sequence according to said interfering energy judgement method, said threshold value judgement method and said iterations judgement method;

Selected cell is used for according to external control signal, selects an acquiring unit in said first acquiring unit to the, seven acquiring units to obtain peak clipping sequence.

11. a multicarrier system comprises subcarrier processing unit and receiving system, it is characterized in that,

Said subcarrier processing unit; Be used to select the subcarrier conduct reservation subcarrier corresponding of other user terminal with the data subcarrier at active user terminal; The data subcarrier at said active user terminal is all subcarriers that said active user's terminal distribution arrives, and whole wave bands of the data subcarrier at said active user terminal are used for transmission of data signals; The peak clipping sequence corresponding with the frequency-region signal of said active user's terminal transmission is modulated on the said reservation subcarrier;

Said receiving system is used to receive said frequency-region signal, and said frequency-region signal is handled.

12. multicarrier system according to claim 11; It is characterized in that; Said subcarrier processing unit also is used for, and at least a method is carried out the iteration decision process in application of interference energy judgement method, threshold value judgement method and the iterations judgement method, obtains said peak clipping sequence.

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