CN101359984A - Method, apparatus and system implementing signal transmission - Google Patents

Abstract

An embodiment of the invention discloses a method for realizing signal transmission, which comprises: digital modulation is performed to data sequence and pilot frequency sequence, and signals awaiting transmission are obtained by mapping the modulated data sequence and the modulated pilot frequency sequence on corresponding time-frequency source positions; the signals awaiting transmission is preprocessed according to the channel response massages estimated during downlink receiving signals, and the actual signals awaiting transmission are obtained; Orthogonal Frequency Division Multiplexing OFDM modulation is performed to the actual signals awaiting transmission, and the modulated signals are transmitted out. With the method, because the symmetry of the channels in the TDD mode is fully utilized, uplink signals can greatly resist the influence by deep fade through adopting the channel response messages estimated during downlink receiving signals to preprocess the signals transmitted by the uplink, and the performances of a system are further improved. Embodiments of the invention also disclose a device and a system for realizing signal transmission.

Description

Realize signal method for transmitting, Apparatus and system

Technical field

The present invention relates to communication technical field, relate in particular to and realize signal method for transmitting, Apparatus and system.

Background technology

Current, along with the continuous development of the communication technology, OFDM (OFDM) technology is more and more used.The OFDM technology can be divided into frequency spectrum a plurality of subcarriers as a kind of multi-carrier transmission technology, and adopts lower data rate to modulate to each subcarrier.Because OFDM has good ability of anti-multipath, therefore in cellular mobile system, be used widely.By distributing different subcarriers, can realize that the multiple access of OFDM inserts (OFDMA) to different users.Each narrow-band sub-carriers can adopt different modulation systems, and for example 16QAM, 64QAM etc. adopt contrary fast fourier transform (IFFT) to realize the OFDM modulation then.Need the data of transmission to be mapped on the symbol of OFDM,, add Cyclic Prefix, send through behind the IFFT.Receiving terminal utilizes Fourier transform (FFT) to solve the OFDM symbol, takes out the data that are mapped to this symbol.

In the OFDMA system, resource that can be different to the different user assignment as time, space, frequency resource etc., thereby realizes different user to the sharing of resource, and simultaneity factor must indicate its data of each terminal to transmit on which resource.

In the ofdm system of prior art, when adopting coherent detection in system, channel estimating is necessary, at this moment, can use pilot tone as supplementary.Generally speaking, in communication system, all in the signal that sends, add pilot signal, to guarantee the accurate, synchronous and stable of signal.Pilot tone is equivalent to a benchmark of the frequency signal of corresponding certain channel, is as the criterion with pilot tone channel is gained, decays or other a series of calibrations.

In ofdm system, pilot signal is a time-frequency two-dimensional.In order to improve the precision of estimation, can select to insert continuous pilot or scattered pilot, the quantity of pilot tone is the compromise of estimated accuracy and system complexity.The coherence time and the coherence bandwidth of channel depended at interval between the pilot signal, and on time domain, the interval of pilot tone should be less than coherence time; On frequency domain, the interval of pilot tone should be less than coherence bandwidth.In the practical application, the design of the pattern of pilot tone will be decided as the case may be.

Basic process based on the OFDM channel estimation methods of pilot tone is: insert pilot tone in the transmitting terminal appropriate location, receiving terminal utilizes pilot tone to recover the channel response information of pilot frequency locations, utilize certain processing means then, as interpolation, filtering, conversion etc., obtain the channel response information of all running time-frequency resources.

Referring to Fig. 1, in the prior art, finish transmitting and receiving of signal in the following way:

The data sequence that need to send is carried out serial/parallel conversion through after the digital modulation, inserts pilot tone in the position of making an appointment, and then launches after comprising the FFT conversion and adding the OFDM modulation operations of CP etc.;

The signal launched arrives reception antenna through the time delay and the decline of wireless channel, goes CP, IFFT operation, isolates data symbol and frequency pilot sign in that this signal has been passed through, and after the parallel/serial conversion, obtains through data sequence and pilot frequency sequence behind the channel fading;

Decline pilot signal and local reference pilot signal are compared, estimate channel response; The channel response that utilizes estimation to obtain carries out equilibrium to the data sequence of decline, removes the influence of wireless channel decline; Then, carry out digital demodulation, recover to obtain original data sequence carrying out the balanced data sequence.

Though above-mentioned coherent detection mode can obtain channel response by the channel estimating that transmit leg inserts pilot tone and recipient and recover original transmission signal, but, when being in deep fade, noise relative influence to received signal becomes big, causes the reduction of systematic function thus.

Simultaneously, in the prior art, time division duplex (TDD) is used for separating receiving and send channel as a kind of duplex mode of communication system in wireless communication system.In the mobile communication system of tdd mode, the different time-gap that receives and be transmitted in same frequency channels carries out, and adopts guard time to separate reception and send channel.

Adopt the communication system of tdd mode that following characteristics are arranged:

(1) do not need paired frequency, can use various frequency resources, be applicable to asymmetric up-downgoing message transmission rate, be specially adapted to the data service of IP type;

(2) uplink and downlink works is in same frequency, and the symmetry characteristic of electric wave transmission makes it new technologies such as smart antenna easy to use, reaches the purpose that improves performance, reduces cost;

(3) equipment cost is lower, than the low 20%-50% of FDD system.

Summary of the invention

Embodiment of the invention technical problem to be solved is: signal method for transmitting, device and the system of realizing is provided, and noise further improves the performance of system to the influence of signal emission during with the reduction deep fade.

For achieving the above object, the embodiment of the invention provides following technical scheme:

A kind of realization signal method for transmitting, this method comprises:

Data sequence and pilot frequency sequence are carried out digital modulation, on the pairing running time-frequency resource position that data sequence after will modulating respectively and pilot frequency sequence are mapped to, obtain signal to be transmitted;

The channel response information that estimates during according to descending the reception carries out preliminary treatment to signal to be transmitted, obtains actual signal to be transmitted;

Described actual signal to be transmitted is carried out the modulating in OFDM operation, and the signal that will obtain after will modulating is launched.

A kind of device of realizing the signal emission, this device comprises:

Channel estimating unit is used for the descending pilot frequency according to descending reception, channel response information when estimating to draw descending reception the and output;

Amending unit is used to utilize the channel response information that receives, and after signal to be transmitted is revised, obtains actual signal to be transmitted.

A kind of system that realizes the signal emission, this system comprises: digital modulation unit, map unit, pretreatment unit and OFDM modulation operations unit, wherein:

Described digital modulation unit is used for: data sequence and pilot frequency sequence are carried out digital modulation, and the data sequence after will modulating and pilot frequency sequence send to map unit;

Described map unit is used for: the pairing running time-frequency resource position that data sequence after will modulating and pilot frequency sequence are mapped to obtains signal to be transmitted;

Described pretreatment unit is used for: the channel response information that estimates during according to descending the reception, signal to be transmitted is carried out preliminary treatment, and obtain actual signal to be transmitted;

Described OFDM modulation operations unit is used for: described actual signal to be transmitted is carried out the OFDM modulation operations, and the signal that will obtain after will modulating is launched.

As seen, in embodiments of the present invention, owing to made full use of the symmetry of the pattern lower channel of TDD, thereby the channel response information that estimates when adopting descending the reception carries out preliminary treatment to the signal of up transmission, make upward signal can be good at resisting the influence of deep fade, further improve the performance of system it.

Description of drawings

Fig. 1 is for realizing the schematic diagram that signal transmits and receives in the prior art;

Fig. 2 realizes signal method for transmitting flow chart for the embodiment of the invention;

Fig. 3 realizes signal method for transmitting flow chart in the embodiment of the invention one;

Fig. 4 is the method flow diagram of performing step 302 in the embodiment of the invention one;

Fig. 5 realizes signal method for transmitting flow chart in the embodiment of the invention two;

Fig. 6 is the schematic diagram of the system that the embodiment of the invention provided;

Fig. 7 is the schematic representation of apparatus of the realization signal emission that the embodiment of the invention provided.

Embodiment

In embodiments of the present invention, the inventor notices:

Under the TDD duplex mode, because the up-downgoing channel has symmetry, thus, in embodiments of the present invention, utilize the symmetry of channel in the TDD mode, the channel response information that estimates during according to descending receive carries out preliminary treatment to transmitting, thereby noise is to the influence of signal emission during the opposing deep fade.

Below in conjunction with accompanying drawing the embodiment of the invention is described in detail.

One, at first, the realization signal method for transmitting that the embodiment of the invention provided is introduced:

Referring to Fig. 2, in embodiments of the present invention, realize that the signal method for transmitting may further comprise the steps:

Step 201: data sequence and pilot frequency sequence are carried out digital modulation, on the pairing running time-frequency resource position that data sequence after will modulating respectively and pilot frequency sequence are mapped to, obtain signal to be transmitted;

Step 202: the channel response information that estimates during according to descending the reception, signal to be transmitted is carried out preliminary treatment, obtain actual signal to be transmitted;

Step 203: described actual signal to be transmitted is carried out the OFDM modulation operations, and the signal that will obtain after will modulating is launched.

Below, in conjunction with example more specifically, the specific implementation of the method that as above provided is described in detail.

(1) embodiment one:

Referring to Fig. 3, in this specific embodiment, realize that the signal emission may further comprise the steps:

Step 301, terminal is carried out digital modulation to data sequence and the pilot frequency sequence that needs send, and then according in advance agreement, on the pairing running time-frequency resource position that data sequence after will modulating respectively and pilot frequency sequence are mapped to, thereby obtains signal to be transmitted;

Step 302: terminal is carried out preliminary treatment according to the channel response information on the time that is estimated by descending pilot frequency to signal to be transmitted, obtains actual signal to be transmitted;

In the present embodiment, whether exceed pre-set threshold according to the mould value of each symbol in the signal after the preliminary treatment, to different preprocess methods should be arranged, thus, referring to Fig. 4, performing step 302 described preliminary treatment need may further comprise the steps:

Step 400:, estimate the channel response on the time according to the descending pilot frequency of descending reception;

Step 401: utilize described channel response that signal to be transmitted is revised, obtain distorted signal;

Step 402: whether the mould value of each symbol of judging described distorted signal greater than pre-set threshold, if, then get the signal of the correction of this threshold value as actual transmission, described correction can be got the argument that threshold value multiply by the channel response conjugation; If not, then with the signal of described distorted signal as actual transmission;

Wherein, described utilize concrete mode that channel response revises signal to be transmitted can for:

Signal to be transmitted is multiplied by the conjugation of the channel response that estimates, again divided by the channel response mould square, thereby obtain distorted signal, also can adopt other modes certainly, an influence that only needs to reduce deep fade gets final product.

Described pre-set threshold can be the higher limit of symbol mould value in the signal, also can be predefined a certain fixing threshold value, does not influence realization of the present invention.

More succinct in order to describe, can adopt following formula (1) to explain above-mentioned pretreatment mode:

$T_{\mathrm{ij}}=\left\{\begin{array}{cc}{S}_{\mathrm{ij}}{H}_{\mathrm{ij}}^{*}/{\left|H_{\mathrm{ij}}\right|}^2,& |S_{\mathrm{ij}}{H}_{\mathrm{ij}}^{*}/{\left|H_{\mathrm{ij}}\right|}^2|<V\\ V*\arg \left(S_{\mathrm{ij}}{H}_{\mathrm{ij}}^{*}\right),& |S_{\mathrm{ij}}{H}_{\mathrm{ij}}^{*}/{\left|H_{\mathrm{ij}}\right|}^2|\&GreaterEqual;V\end{array}\right.$ Formula (1)

Wherein, S _IjRepresent the signal to be transmitted on each time-frequency piece, i=1,2 ... 8; J=1,2 ... 128; H _IjBe the channel response of each time-frequency piece, i=[i], j=[j], T _IjBe actual signal to be transmitted; V is the maximum magnitude or a certain threshold value of predefined signal power, H _Ij ^*Expression channel response H _IjConjugation, | H _Ij| expression channel response H _IjMould.

Step 303: launch after described actual signal to be transmitted comprised serial/parallel conversion, FFT conversion and add the OFDM modulation operations of CP etc.

So far, the signal transmitting method that is provided in the embodiment of the invention is finished, the signal that this method is launched, in wireless channel, transmit, time delay and decline through wireless channel, arrive reception antenna, this signal through going CP, IFFT operation, parallel/serial conversion after, isolate through data sequence and pilot frequency sequence behind the channel fading.

For the method that embodies the embodiment of the invention and provide can effectively reduce the influence of deep fade to the signal emission, existing situation of change to the signal launched is analyzed;

With reference to following formula (2), as actual signal to be transmitted T _IjWhen arriving receiving terminal after the process effect of real channel response, receiving terminal receives and obtains received signal R _IjFor:

$R_{i,j}=T_{i,j}{H}_{i,j}^{\&prime;}=\left\{\begin{array}{cc}{S}_{\mathrm{ij}}{H}_{\mathrm{ij}}^{*}/{\left|H_{\mathrm{ij}}\right|}^2{H}_{i,j}^{\&prime;}+N,& |S_{\mathrm{ij}}{H}_{\mathrm{ij}}^{*}/{\left|H_{\mathrm{ij}}\right|}^2|<V\\ V*\arg \left(S_{\mathrm{ij}}{H}_{\mathrm{ij}}^{*}\right)H_{i,j}^{\&prime;}+N,& |S_{\mathrm{ij}}{H}_{\mathrm{ij}}^{*}/{\left|H_{\mathrm{ij}}\right|}^2|\&GreaterEqual;V\end{array}\right.$ Formula (2)

Wherein, described H _{I, j}The actual channel response that experiences of ' expression signal institute.

If become slower during channel, think H _IjAnd H _{I, j}' approximately equal, the then represented received signal R of formula (2) _IjCan be approximated to be:

$R_{\mathrm{ij}}=\left\{\begin{array}{cc}{S}_{\mathrm{ij}}+N,& |S_{\mathrm{ij}}{H}_{\mathrm{ij}}^{*}/{\left|H_{\mathrm{ij}}\right|}^2|<V\\ V*\arg \left(S_{\mathrm{ij}}\right)\left|H_{i,j}^{\&prime;}\right|+N,& |S_{\mathrm{ij}}{H}_{\mathrm{ij}}^{*}/{\left|H_{\mathrm{ij}}\right|}^2|\&GreaterEqual;V\end{array}\right.$ Formula (3)

At this moment,, can draw:, then utilize pilot signal to estimate that the pseudo-channel response that draws is if adopt the method that the embodiment of the invention provided according to formula (3) and formula (1):

$\tilde{H}=\frac{R_{i,j}}{S_{i,j}}\&ap;\left\{\begin{array}{cc}1+N/S_{i,j},& |S_{\mathrm{ij}}{H}_{\mathrm{ij}}^{*}/{\left|H_{\mathrm{ij}}\right|}^2|<V\\ V*\left|H_{i,j}^{\&prime;}\right|/\left|S_{\mathrm{ij}}\right|+N/S_{i,j},& |S_{\mathrm{ij}}{H}_{\mathrm{ij}}^{*}/{\left|H_{\mathrm{ij}}\right|}^2|\&GreaterEqual;V\end{array}\right.$ Formula (4)

By formula (3) as seen, owing at transmit leg signal to be transmitted has been carried out preliminary treatment, the signal to be transmitted before signal and the transmit leg preliminary treatment of channel fading that made experience that in fact recipient receives is very approaching, if think change when channel almost has, H _IjAnd H _{I, j}' equating that the signal that receives so is exactly the signal to be transmitted before the transmit leg preliminary treatment, visible this programme has shielded the influence of channel deep fade greatly; Equally as seen by formula (4), the recipient is through after the channel estimating operation, channel response is 1 or real number, for almost not influence of the signal to be transmitted before the transmit leg preliminary treatment, so adopt the method that the embodiment of the invention provided, can reduce the influence of deep fade greatly to the signal emission.

(2) embodiment two:

In embodiment one, each signal to be transmitted is all carried out described preliminary treatment, but, in actual applications, existence only is the situation that the part signal in the signal to be transmitted is subjected to the deep fade influence, at this moment, obviously need not all signals in the signal to be transmitted are all carried out preliminary treatment, in the embodiment of the invention two, at this kind situation, the embodiment of the invention two can adopt following mode shown in Figure 5 to realize preliminary treatment:

Step 500:, estimate the channel response of time according to the descending pilot frequency of descending reception;

Step 501: judge whether the current channel response that estimates is the channel response that declines deeply, if not, then directly with current signal to be transmitted as pretreated actual signal to be transmitted, if, then execution in step 502 and subsequent step thereof;

Step 502～step 503 pair signal to be transmitted is revised, and its makeover process is in full accord with the described process of step 401～step 402, does not repeat them here; Certainly, in the embodiment of the invention two, also can adopt other modes to finish correction, not influence realization of the present invention signal to be transmitted.

More succinct in order to describe, adopt following formula (5) statement embodiment two described pretreatment modes:

Formula (5)

Wherein, K is the thresholding that declines deeply.

(3) embodiment three:

In embodiment two, whether be in deep fade according to channel response and adopt different pretreatment modes, in present embodiment three, according to the channel response that whether can obtain on pairing all time of signal to be transmitted, decide and carry out overall situation adjustment or local the adjustment in preprocessing process, its specific implementation is:

Adopt all available channel responses that corresponding signal to be transmitted is carried out correcting process, if can obtain the channel response on the pairing time of whole signals to be transmitted, then the correction result to signal to be transmitted shows as: adopt channel response that signal to be transmitted is carried out overall situation adjustment; If only can obtain the channel response on the pairing time of part signal to be transmitted, then this moment the correction result of signal to be transmitted is shown as: adopt channel response that signal to be transmitted is carried out part adjustment.

In this embodiment, can adopt the described mode of step 401～step 402 to finish correction, also can adopt other modes to carry out, not influence realization of the present invention signal to be transmitted.

More succinct in order to describe, adopt following formula (6) statement embodiment three described pretreatment modes:

Formula (6)

(4) embodiment four:

In actual applications, the amplitude of signal to be transmitted is certain, and its phase change is also less; But, channel response H _IjPhase place and amplitude all can carry out bigger variation, thus, in the embodiment of the invention four, in order to simplify the kind that transmits, preestablish phase level and amplitude grade, when utilizing channel response that signal to be transmitted is revised, utilize described predefined phase level and amplitude grade that channel response is quantized, thereby further simplify the implementation procedure of the embodiment of the invention.

For example, in advance phase place and amplitude are set corresponding grade respectively, each grade has point of quantification separately respectively, for example: regulation H _Ij ^*The quantification gradation of mould be 5 grades { 0,1,2,3,4}, the quantification gradation of argument be 4 grades of { pi/4,3pi/4,5pi/4,7pi/4}; At this moment, for certain H _Ij ^*; according to the grade that as above sets, respectively its mould value and argument value are carried out quantization operation, be specifically as follows: for dropping on the quantification that can round up of value between certain two point of quantification; also can round quantification downwards, but must guarantee that rounding the result is nearest point of quantification; If mould value or argument value surpass quantizing range, then round quantification to nearest point of quantification.

In the case, for $H_{\mathrm{ij}}^{*}=3.25*\arg (\mathrm{pi}/3),$ After nearest point of quantification rounds quantification be: $H_{\mathrm{ij}}^{*}=3*\arg (\mathrm{pi}/4).$

In this way, can simplify the kind that transmits, help the smooth realization of the embodiment of the invention.

(5) embodiment five:

In actual applications, signal to be transmitted is carried out directly launching after the preliminary treatment, pretreated total transmitting power might occur and surpass the preceding total transmitting power that is untreated, consistency and the whole power control of guarantee for power before and after keeping, in the embodiment of the invention five, before with the signal emission, further calculate and compare the signal power of preliminary treatment front and back, if total power signal diminishes after the preliminary treatment, then directly emission, if total power signal becomes big after the preliminary treatment, then unified be multiplied by one greater than 0 less than 1 correction factor, in the present embodiment, this correction factor is: δ=∑ | S _Ij| ²/ ∑ | T _Ij| ², obvious δ＜1 here.By this kind mode, pretreated signal power can be normalized to the gross power before the preliminary treatment, thereby satisfy the conforming requirement of power.

Here why only under the big situation of power change, just carry out described normalized, be because if also multiply by δ when gross power diminishes behind the preequalization, then the power on some time-frequency piece might surpass maximum power or threshold value again, after adopting the peak clipping shown in this programme to handle, gross power still is less than normal, need repeat repeatedly like this, operate cumbersome.Certainly,, in the preferred embodiment of the present invention, can limit number of times to above-mentioned normalized for fear of operational loaded down with trivial details, such as a normalization once, to obtain the balance of performance and complexity; Perhaps, also can provide a scope, only exceed under the situation of this scope, just carry out described normalization operation the size of gross power biasing; Reduce 5% such as gross power and just no longer carry out normalization,, like this, also can guarantee the consistency of gross power substantially if reduce above 5% then carry out normalization with interior.

(6) embodiment six:

Because wireless channel becomes when being, when this time when becoming very fast, may cause when sending data channel acute variation, carry out preliminary treatment more at this moment and also just can't work.Consider this situation, in the embodiment of the invention six, before the preliminary treatment of carrying out signal to be transmitted, also can further comprise:

Whether the pace of change of judging the translational speed of terminal or wireless channel has surpassed predefined speed threshold, if then no longer signal to be transmitted is carried out described preliminary treatment, but directly adopt the mode of prior art to finish the emission of signal; If not, then adopt the as above described mode of embodiment, signal to be transmitted is carried out preliminary treatment, to finish the emission of signal.

Wherein, in embodiments of the present invention, adopt the terminal of supporting speed measuring function, utilize its speed measuring function to know the translational speed of this terminal or the pace of change of current channel by this terminal, and this pace of change is compared with predefined speed threshold.

When terminal is not supported speed measuring function, also can adopt some easy modes to judge, relatively more different some constantly, certain is several or the situation of change of whole channel responses: such as the amplitude maximum of channel response and the multiple difference between the minimum value time less than certain thresholding, think that this channel variation is slower, can carry out preliminary treatment, otherwise not carry out preliminary treatment.Perhaps, also can the real part of channel response or imaginary part from just to negative and from negative to positive sign change number of times as basis for estimation, simple example thinks that the no more than channel once of sign change number of times thinks that the time goes up still relevant, preliminary treatment can be carried out, otherwise preliminary treatment cannot be carried out.

Two, below, the system of the realization signal emission that the embodiment of the invention provided is introduced:

Referring to Fig. 6, the system of the realization signal emission that the embodiment of the invention provided comprises digital modulation unit 601, map unit 602, pretreatment unit 603 and OFDM modulation operations unit 604, wherein:

Described digital modulation unit 601 is used for: data sequence and pilot frequency sequence are carried out digital modulation, and the data sequence after will modulating and pilot frequency sequence send to map unit 602;

Described map unit 602 is used for: the pairing running time-frequency resource position that data sequence after will modulating respectively and pilot frequency sequence are mapped to, thus obtain signal to be transmitted S _Ij

Described pretreatment unit 603 is used for: the channel response information that estimates during according to descending the reception, and to signal to be transmitted S _IjCarry out preliminary treatment, obtain distorted signal T _Ij, with this distorted signal as actual signal to be transmitted;

Described OFDM modulation operations unit 604 is used for: to described distorted signal T _IjCarry out the OFDM modulation operations, and the signal that will obtain after will modulating is launched.

Referring to Fig. 6, the signal that described system launches, in time delay and decline through wireless channel, arrive the receiving element 605 of receiver side, 605 pairs of these signals of this receiving element are through comprising CP, the IFFT operation, parallel/serial conversion is after interior OFDM demodulation operation, export signal to pilot data separative element 606, this pilot data separative element 606 is isolated through data sequence and pilot frequency sequence behind the channel fading, and export these sequences to channel estimating unit 607 and balanced unit 608 respectively, channel estimating unit is according to pilot frequency sequence and reference pilot sequence after the decline that receives, estimate to obtain the pseudo-channel response of time-frequency domain of pilot frequency locations, and should export to balanced unit 608 by the puppet channel response, balanced unit 608 utilizes the pseudo-channel response that obtains that the data sequence of decline is carried out equalization operation, and the sequence that will obtain after will operating exports digital demodulation unit 609 to, digital demodulation unit is carried out the digital demodulation operation to the data sequence that obtains, and with the data sequence output that recovers, thereby finish communication process one time.

Three, below, the device of the realization signal emission that the embodiment of the invention provided is introduced in detail:

Referring to Fig. 7, the device of the realization signal emission that the embodiment of the invention provided comprises:

Channel estimating unit 701 is used for the descending pilot frequency according to descending reception, channel response information when estimating to draw descending reception the and output;

Amending unit 702 is used to utilize the channel response information that receives, and after signal to be transmitted is revised, obtains actual signal to be transmitted.

Wherein, in the preferred embodiment of the present invention, described amending unit comprises:

Distorted signal computing unit: be used to utilize described channel response information, described signal to be transmitted is calculated, obtain distorted signal;

Judging unit: whether the power that is used to judge described distorted signal is greater than pre-set threshold, if then get the signal of the correction of this threshold value or this threshold value as actual transmission; If not, then with the signal of described distorted signal as actual transmission.

Described distorted signal computing unit comprises:

Multiplication unit is used for signal to be transmitted is multiplied by the conjugation of the channel response information that estimates, and multiplied result is exported to divider;

Divider, be used for the multiplied result that will receive divided by described channel response information mould square, thereby obtain distorted signal.

In another preferred embodiment of apparatus of the present invention, described device also can further comprise:

Channel response information screening unit is used for the channel response information that estimates from channel estimating unit 701, and screening obtains the channel response information less than the thresholding that declines deeply, and the response message after will screening exports amending unit 702 to.

In another preferred embodiment of apparatus of the present invention, described device also can further comprise:

The channel response information quantifying unit is used for according to predefined quantification gradation, and the channel response information that channel estimating unit 701 is estimated carries out quantization operation, and exports the channel response information after the quantization operation to amending unit 702.

In another preferred embodiment of apparatus of the present invention, described device also can further comprise:

Whether big the power control unit be used to judge and carry out the total power signal that obtains after the described correction gross power with described signal to be transmitted, if then carry out the normalization operation to obtaining signal after revising, so that its gross power is consistent with the gross power of signal to be transmitted.

In another preferred embodiment of apparatus of the present invention, described device also can further comprise:

The unit that tests the speed is used to know the pace of change of current channel, and only during less than predefined speed threshold, instructs described channel estimating unit 701 and amending unit 702 to realize function separately in this pace of change.

The above only is a preferred implementation of the present invention; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the principle of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (15)

1, a kind of realization signal method for transmitting is characterized in that this method comprises:

Data sequence and pilot frequency sequence are carried out digital modulation, on the pairing running time-frequency resource position that data sequence after will modulating respectively and pilot frequency sequence are mapped to, obtain signal to be transmitted;

The channel response information that estimates during according to descending the reception carries out preliminary treatment to signal to be transmitted, obtains actual signal to be transmitted;

Described actual signal to be transmitted is carried out the modulating in OFDM operation, and the signal that will obtain after will modulating is launched.

2, method according to claim 1 is characterized in that, describedly signal to be transmitted is carried out preliminary treatment comprises:

According to the predefined thresholding that declines deeply, filter out channel response information the channel response information that estimates during from described descending receive less than this thresholding, utilize this channel response information that filters out that signal to be transmitted is carried out preliminary treatment.

3, method according to claim 1 is characterized in that, describedly signal to be transmitted is carried out preliminary treatment comprises:

All channel response informations that employing can obtain carry out preliminary treatment to signal to be transmitted.

4, method according to claim 1 is characterized in that, describedly signal to be transmitted is carried out preliminary treatment comprises:

According to predefined quantification gradation, the channel response information that estimates during to described descending receive carries out quantization operation, utilizes the channel response information after this quantization operation that signal to be transmitted is carried out preliminary treatment.

5, method according to claim 1 is characterized in that, the gross power of the signal that obtains after judgement obtains preliminary treatment is during greater than the gross power of described signal to be transmitted, and described preliminary treatment further comprises:

Pretreated signal is carried out the normalization operation, so that its gross power is consistent with the gross power of signal to be transmitted.

6, according to any described method of claim 1～5, it is characterized in that, describedly signal to be transmitted is carried out preliminary treatment comprise:

According to the descending pilot frequency of descending reception, estimate the channel response of time;

Utilize described channel response that signal to be transmitted is revised, obtain distorted signal;

Whether the power of judging described distorted signal is greater than pre-set threshold, if then get the signal of the correction of this threshold value or this threshold value as actual transmission; If not, then with the signal of described distorted signal as described actual transmission.

7, method according to claim 6 is characterized in that, describedly utilizes described channel response that signal to be transmitted correction is specially:

Signal to be transmitted is multiplied by the conjugation of the channel response that estimates, again divided by the channel response mould square, thereby obtain distorted signal.

8, a kind of device of realizing the signal emission is characterized in that this device comprises:

Channel estimating unit is used for the descending pilot frequency according to descending reception, channel response information when estimating to draw descending reception the and output;

Amending unit is used to utilize the channel response information that receives, and after signal to be transmitted is revised, obtains actual signal to be transmitted.

9, device according to claim 8 is characterized in that, this device further comprises:

Channel response information screening unit is used for the channel response information that estimates from described channel estimating unit, and screening obtains the channel response information less than the thresholding that declines deeply, and the response message after will screening exports described amending unit to.

10, device according to claim 8 is characterized in that, this device further comprises:

The channel response information quantifying unit is used for according to predefined quantification gradation, and the channel response information that described channel estimating unit is estimated carries out quantization operation, and exports the channel response information after the quantization operation to described amending unit.

11, device according to claim 8 is characterized in that, this device further comprises:

The power control unit, be used to judge that whether big amending unit revise the total power signal that obtains after the operation gross power with described signal to be transmitted, if then carry out the normalization operation, so that its gross power is consistent with the gross power of signal to be transmitted to obtaining signal after revising.

12, device according to claim 8 is characterized in that, this device further comprises:

The unit that tests the speed is used to know the pace of change or the moving velocity of terminal of current channel, and only during less than predefined speed threshold, instructs described channel estimating unit and amending unit to realize function separately in this pace of change or translational speed.

13, according to Claim 8 any～12 described device is characterized in that described amending unit comprises:

Distorted signal computing unit: be used to utilize described channel response information, described signal to be transmitted is calculated, obtain distorted signal;

Judging unit: whether the power that is used to judge described distorted signal is greater than pre-set threshold, if then get the signal of the correction of this threshold value or this threshold value as actual transmission; If not, then with the signal of described distorted signal as actual transmission.

14, device according to claim 13 is characterized in that, described distorted signal computing unit comprises:

Multiplication unit is used for signal to be transmitted is multiplied by the conjugation of the channel response information that estimates, and multiplied result is exported to divider;

Divider, be used for the multiplied result that will receive divided by described channel response information mould square, thereby obtain distorted signal.

15, a kind of system that realizes the signal emission is characterized in that this system comprises: digital modulation unit, map unit, pretreatment unit and OFDM modulation operations unit, wherein:

Described digital modulation unit is used for: data sequence and pilot frequency sequence are carried out digital modulation, and the data sequence after will modulating and pilot frequency sequence send to map unit;

Described map unit is used for: the pairing running time-frequency resource position that data sequence after will modulating and pilot frequency sequence are mapped to obtains signal to be transmitted;

Described pretreatment unit is used for: the channel response information that estimates during according to descending the reception, signal to be transmitted is carried out preliminary treatment, and obtain actual signal to be transmitted;

Described OFDM modulation operations unit is used for: described actual signal to be transmitted is carried out the OFDM modulation operations, and the signal that will obtain after will modulating is launched.

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