CN101753502B - Signal processing method and signal processing device - Google Patents

Abstract

The invention discloses a signal processing method. Data to be transmitted after the trellis coding is pre-coded to generate a pre-coding data, the pre-coding data is mapped through a constellation diagram to generate a mapping data, the mapping data is coded to generate relevant coding data, and finally an OFDM symbol is generated by carrying out IFFT of the relevant coding data, and the OFDM symbol is transmitted after being processed. The invention also discloses a signal processing device. Attenuation outside a channel of a sub-carrier is accelerated through the pre-coding and relevant coding, and the leakage outside the channel of the sub-carrier sidelobe is reduced, so the energy of the sub-carrier main lobe is more concentrated so as to further deepen the concave depth of a frequency spectrum and to eliminate the interference on relevant frequency bands.

Description

A kind of signal processing method and signal processing apparatus

Technical field

The present invention relates to communication technical field, relate in particular to a kind of signal processing method and signal processing apparatus.

Background technology

Along with the develop rapidly of modern society to continuous growth of the demand of radio communication and wireless communication technology; Wireless communication user is a large amount of sharply to be increased; On the other hand, along with people's growth in the living standard, people to radio communication require increasingly high; More existing wireless communication technologys can't satisfy some like emerging demands of applications such as home theater, video request program, the accesses of ultrahigh speed internet, thereby make the frequency spectrum resource the be applicable to radio communication growing tension that becomes.The common radiation of the short distance wireless communication technology is little, and is little to contiguous communication equipment interference, can reuse frequency spectrum resource; Transmission speed is high; Therefore, in recent years, the short distance wireless communication technology receives extensive attention and obtains fast development; (Ultra Wideband, UWB) technology is regarded as one of key technology of next generation wireless communication to ultra broadband.

Based on Mb-ofdm ultra broadband (Multi-Band Orthogonal Frequency DivisionMultiplexing Ultra Wideband; MB-OFDM UWB) system is with (the FederalCommunications Commission of Federal Communications Committee; FCC) unlicensed frequency band of the 3.1GHz-10.6GHz that distributes is divided into 14 subbands; Each subband is 528MHz, is used for sending the ofdm signal of 128 points, and each subcarrier takies the bandwidth of 4.125MHz.

(Cognitive Radio CR) is meant a kind of wireless communication technology that comprises smart transceiver to cognitive radio, and this transceiver can Intelligent Measurement goes out unoccupied and which frequency range of which frequency range to be used.When detecting some frequency range when unoccupied, the CR system just can temporarily use this wave band to communicate.When detecting some frequency range just in time in the current transmit frequency band of CR system, the CR system can change the frequency range of native system emission to avoid authorized user, perhaps is reduced in the transmitting power on the corresponding band, to reduce the interference to authorized user.The MB-OFDM technology is to realize the preferred option of CR technology.

As shown in Figure 1, be European Computer Manufacture's Association's (European Computer ManufacturersAssociation, ECMA) MB-OFDM UWB system block diagram of definition.Physical layer convergence protocol (Physical Layer Convergence Protocol; PLCP) packet header comprises some information of bag; PSDU presentation service data unit (Presentation Service Data Unit; PSDU) then comprise data message; PLCP packet header and PSDU respectively through convolution coding, interweave, planisphere mapping, close subcarrier, form the OFDM symbol, and with close leading character behind the subcarrier and merge and generate packet, launch through being modulated on the corresponding carriers after the digital-to-analogue conversion.The Mathematical Modeling of its baseband signal is:

$s_n\left(t\right)=w_T\left(t\right)\underset{k=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{d}_{k,n}\exp \left(\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;k\&Delta;ft}\right)---\left(1\right)$

Wherein, s _n(t) be the time-domain representation of single baseband signalling; N is a total number of sub-carriers, promptly anti-FFT (Inverse Fourier Transform, counting IFFT); Δ f is a subcarrier spacing; d _{K, n}Be the data that are modulated on each number of sub-carrier.Do not consider that (zero-padded suffix, ZPS), the duration of whole OFDM symbol is T to the zero padding suffix _s=T _FFT=1/ Δ f; w _T(t) be window function, be defined as:

$w_T\left(t\right)=\left\{\begin{array}{cc}{\sin }^2\left[\frac{\mathrm{\&pi;}}{2}(0.5+\frac{1}{T_{\mathrm{TR}}})\right]& -\frac{{\mathrm{<figure-callout\; id="2"\; label="T\; TR"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">T</figure-callout>}}_{\mathrm{TR}}}{2}<t<\frac{{\mathrm{<figure-callout\; id="2"\; label="T\; TR"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">T</figure-callout>}}_{\mathrm{TR}}}{2}\\ 1& \frac{{\mathrm{<figure-callout\; id="2"\; label="T\; TR"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">T</figure-callout>}}_{\mathrm{TR}}}{2}<t<T_s-\frac{{\mathrm{<figure-callout\; id="2"\; label="T\; TR"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">T</figure-callout>}}_{\mathrm{TR}}}{2}\\ {\sin }^2\left[\frac{\mathrm{\&pi;}}{2}(0.5-\frac{t-T_s}{T_{\mathrm{TR}}})\right]& T_s-\frac{{\mathrm{<figure-callout\; id="2"\; label="T\; TR"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">T</figure-callout>}}_{\mathrm{TR}}}{2}<t<T_s+\frac{T_{\mathrm{TR}}}{2}\end{array}\right.---\left(2\right)$

In the formula, T _TRBe intersymbol transit time.

Through the planisphere mapping, the data that can be modulated on the subcarrier are expressed as:

$d_{k,n}=\left(R_{k,n}{e}^{j{\mathrm{\&theta;}}_{k,n}}\right)K_{\mathrm{MOD}}---\left(3\right)$

Wherein, $R_{k,n}=\sqrt{{x_{k,\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">n</figure-callout>}}}^2+{y_{k,\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">n</figure-callout>}}}^2},$ θ _{K, n}=tan ^-1(y _{K, n}/ x _{K, n}), x _{K, n}And y _{K, n}Be respectively the component of mapping back data on x axle and y axle; K _MODBe normaliztion constant, thereby have:

$s\left(t\right)=\underset{n=-\&infin;}{\overset{\&infin;}{\mathrm{\&Sigma;}}}{w}_T(t-\mathrm{nTs})\underset{k=0}{\overset{N}{\mathrm{\&Sigma;}}}\left(R_{k,n}{e}^{j{\mathrm{\&theta;}}_{k,n}}{K}_{\mathrm{MOD}}\right)\exp \left(\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;k\&Delta;f}(t-\mathrm{nTs})\right)$

$=\underset{n=-\&infin;}{\overset{\&infin;}{\mathrm{\&Sigma;}}}\underset{k=0}{\overset{N}{\mathrm{\&Sigma;}}}{R}_{k,n}{K}_{\mathrm{MOD}}{w}_T(t-\mathrm{nTs})\exp \left(j(2\mathrm{\&pi;k\&Delta;f}(t-\mathrm{nTs})+{\mathrm{\&theta;}}_{k,n})\right)$

$=\underset{k=0}{\overset{N}{\mathrm{\&Sigma;}}}(\underset{n=-\&infin;}{\overset{\&infin;}{\mathrm{\&Sigma;}}}{R}_{k,n}{K}_{\mathrm{MOD}}{w}_T(t-\mathrm{nTs})\exp \left(j(2\mathrm{\&pi;k\&Delta;f}(-\mathrm{nTs})+{\mathrm{\&theta;}}_{k,n}){\mathrm{<figure-callout\; id="2"\; label="e\; j"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">e</figure-callout>}}^j\right)$

$=\underset{k=0}{\overset{N}{\mathrm{\&Sigma;}}}{g}_k\left(t\right){\mathrm{<figure-callout\; id="2"\; label="e\; j"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">e</figure-callout>}}^j---\left(4\right)$

Wherein, $g_k\left(t\right)=\underset{n=-\&infin;}{\overset{\&infin;}{\mathrm{\&Sigma;}}}{R}_{k,n}{K}_{\mathrm{MOD}}{w}_T(t-\mathrm{NTs})\mathrm{Exp}(j(2\mathrm{\&pi;\; K\&Delta;\; f}(-\mathrm{NTs})+{\mathrm{\&theta;}}_{k,n})$ Be the mathematic(al) representation of OFDM single sub-carrier signal, so the power spectral density of single sub-carrier waveform is:

$P_{g_k}\left(f\right)=\frac{{\left|W_T\left(f\right)\right|}^2}{T_s}\underset{n=-\&infin;}{\overset{\&infin;}{\mathrm{\&Sigma;}}}R\left(k\right){\mathrm{<figure-callout\; id="2"\; label="e\; j"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">e</figure-callout>}}^j---\left(5\right)$

Wherein, $W_T\left(f\right)=T_s\mathrm{Sin}c\left(T_{s}f\right)=\frac{\mathrm{Cos}\left(\mathrm{\&pi;}{T}_{\mathrm{TR}}f\right)}{1-4T_{\mathrm{TR}}^2{f}^2}{e}^{-\mathrm{J\&pi;}{T}_{s}f}$ Be time window function w _t(f) Fourier transform.

The power spectral density expression formula that further derivation can obtain whole OFDM symbol is:

$P_s\left(f\right)=R_s\underset{k=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{\left|W_T(f-\mathrm{k\&Delta;f})\right|}^2---\left(6\right)$

R wherein _s=1/T _sBe character rate.

The OFDM symbol can produce spectral notch through the closed portion subcarrier and reduce the interference to existing narrowband systems.Suppose that MB-OFDM UWB system detects $[{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">f</figure-callout>}}_1,f_2]\&Subset;[0,(N-1)\mathrm{\&Delta;\; f}]$ Have a certain narrowband systems, MB-OFDM UWB system needs [K ₁, K ₂] between subcarrier close to produce spectral notch, wherein K ₁=floor (f ₁/ Δ f), floor is downward bracket function, K ₂=ceil (f ₂/ Δ f), ceil is the function that rounds up.Tone nulling (Tone-Nulling) matrix is with K ₁The position is to K ₂ Position 0, the element of all the other positions is changed to 1, and the power spectral density function that can get the recessed position of this moment is:

$\begin{array}{cc}{P}_{\mathrm{notch}}\left(f\right)=R_s(\underset{k=0}{\overset{K_1}{\mathrm{\&Sigma;}}}{\left|W_T(f-\mathrm{k\&Delta;f})\right|}^2+\underset{k=K_2}{\overset{N-1}{\mathrm{\&Sigma;}}}{\left|W_T(f-\mathrm{k\&Delta;f})\right|}^2)& f\&Element;[{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">f</figure-callout>}}_1,f_2]\end{array}---\left(7\right)$

Above-mentioned MB-OFDM UWB system adopts is the unlicensed spectrum of the 3.1GHZ-10.6GHz that divides of international standard; And the usable spectrum of Chinese ultra broadband standard is 4.2GHZ-4.8GHZ and 6.0GHZ-8.55GHZ; So in the frequency spectrum planning of China; At some restricted area, for example in the 3.6-6.0GHz scope, the transmitting power of ultra-broadband signal there is strict restriction.

The inventor is in realizing process of the present invention; The technology of finding above-mentioned prior art limit transmit power is directly to close to have corresponding subcarrier on the frequency band that disturbs; The spectral notch degree of depth that this technology produces is not enough, fails to reach the purpose of elimination to the interference of frequency band.

Summary of the invention

In view of above-mentioned existing in prior technology problem, the embodiment of the invention provides a kind of signal processing method and signal processing apparatus, to deepen the ofdm signal spectral notch, eliminates the interference to frequency band.

In order to reach the foregoing invention purpose, the embodiment of the invention provides a kind of signal processing method, comprising:

Data to be sent behind the interweaving encoding are carried out precoding generate pre-code data;

Said pre-code data is carried out the planisphere mapping generate mapping (enum) data;

Said mapping (enum) data is carried out correlative coding generate the correlative coding data;

Said correlative coding data are carried out inverse fast fourier transform IFFT generate the orthogonal frequency division multiplex OFDM symbol;

Said OFDM symbol is carried out sending after the handled.

Correspondingly the embodiment of the invention also provides a kind of signal processing apparatus, comprising:

Precoding module is used for that the data to be sent behind the interweaving encoding are carried out precoding and generates pre-code data;

The planisphere mapping block is used for that the pre-code data that said precoding module generates is carried out the planisphere mapping and generates mapping (enum) data;

The correlative coding module is used for that the mapping (enum) data that said planisphere mapping block generates is carried out correlative coding and generates the correlative coding data;

OFDM symbol generation module is used for that the correlative coding data that said correlative coding module generates are carried out IFFT and generates corresponding OFDM symbol;

Sending module is used for said OFDM symbol is carried out sending after the handled.

Correspondingly the embodiment of the invention also provides a kind of signal processing method, comprising:

Reception data after the Synchronous Processing are generated the correlative coding data through the OFDM demodulation;

Said correlative coding data are carried out the correlative coding demodulation generate corresponding mapping (enum) data;

Said mapping (enum) data is carried out planisphere mapping demodulation generate pre-code data;

Said pre-code data is carried out the precoding demodulation generate interleaved encoded data;

Said interleaved encoded data is carried out demodulation and decoding.

Correspondingly the present invention also provides a kind of signal processing apparatus, comprising:

The OFDM demodulation module is used for the reception data after the Synchronous Processing are generated the correlative coding data through the OFDM demodulation;

The correlative coding demodulation module is used for the correlative coding data demodulates that said receiver module generates is generated corresponding mapping (enum) data;

Planisphere mapping demodulation module, the mapping (enum) data demodulation that is used for said correlative coding demodulation module is generated generates pre-code data;

The precoding demodulation module is used for the pre-code data demodulation that said planisphere mapping demodulation module generates is generated interleaved encoded data;

Decoding module is used for the interleaved encoded data that said precoding demodulation module generates is carried out demodulation and decoding.

A kind of signal processing method and device that the embodiment of the invention provides; Generate pre-code data through the data to be sent behind the interweaving encoding being carried out precoding; Said pre-code data is generated mapping (enum) data through the planisphere mapping, then said mapping (enum) data is carried out correlative coding and generate the correlative coding data, at last said correlative coding data are carried out IFFT and generate the OFDM symbol; Said OFDM symbol is carried out sending after the handled; Accelerated the attenuation outside a channel of subcarrier like this through precoding and correlative coding, reduced the band external leakage of subcarrier secondary lobe, made that subcarrier main lobe energy is more concentrated; Thereby can further deepen the spectral notch degree of depth, eliminate interference frequency band.

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 to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art below; Obviously, the accompanying drawing in describing below only 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 a prior art MB-OFDM UWB system architecture diagram;

Fig. 2 is the flow chart of first embodiment of the invention signal processing method;

Fig. 3 is the comparison diagram of embodiment of the invention single sub-carrier frequency spectrum and prior art single sub-carrier frequency spectrum;

Fig. 4 is that the embodiment of the invention and prior art are at the comparison diagram of closing spectral notch under the same band subcarrier situation;

Fig. 5 is a second embodiment of the invention signal processing method flow chart;

Fig. 6 is a third embodiment of the invention signal processing apparatus structural representation;

Fig. 7 is a fourth embodiment of the invention signal processing apparatus structural representation.

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.

Fig. 2 is a first embodiment of the invention signal processing method flow chart, may further comprise the steps:

101, the data to be sent behind the interweaving encoding are carried out precoding and generate pre-code data;

Concrete, data to be sent are passed through to generate interleaved encoded data a behind convolutional encoding and the interweaving encoding _k, according to following formula to said interleaved encoded data a _kCarry out precoding and generate pre-code data b _k:

$b_k=a_k\&CirclePlus;b_{k-1}---\left(8\right)$

Wherein, a _kBe the data to be sent constantly of k behind the interweaving encoding, b _kBe k pre-code data constantly, b _K-1Be k-1 pre-code data constantly,

Be nodulo-2 addition.Said precoding process can be avoided when receiving terminal is decoded because the Error propagation problems that correlative coding causes.

102, said pre-code data is generated mapping (enum) data through the planisphere mapping;

Concrete; In embodiments of the present invention, the mapping mode of said planisphere mapping comprises that (Quadrature Phase Shift Keying QPSK) contrasts mapping (Digital ContrastMapper with numeral to QPSK; DCM); QPSK is divided into the group of a lot of 2bit with the binary data of serial, and converts thereof into a plural number of representing one of 4 QPSK constellation, and the plural number that will obtain is at last used $K_{\mathrm{MOD}}=\sqrt{2}$ Carry out normalization.DCM then is divided into binary data the group of 200bit, and it is mapped on the planisphere of one 4 dimension, uses at last $K_{\mathrm{MOD}}=\sqrt{10}$ With the plural normalization that obtains.

103, said mapping (enum) data is carried out correlative coding and generate the correlative coding data;

Concrete, according to following formula said mapping (enum) data is carried out correlative coding and generates the correlative coding data:

d _k＝c _k-c _k-1 (9)

Wherein, c _kBe k mapping (enum) data constantly, c _K-1Be k-1 mapping (enum) data constantly, d _kBe k correlative coding data constantly.

104, said correlative coding data are generated corresponding OFDM symbol through IFFT;

Concrete, based on following equality said correlative coding data are generated corresponding OFDM symbol through anti-FFT:

$s_n^{\&prime;}\left(t\right)=w_T\left(t\right)\underset{k=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{d}_k\exp \left(\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;k\&Delta;ft}\right)$

$=w_T\left(t\right)\underset{k=1}{\overset{N}{\mathrm{\&Sigma;}}}(c_k-c_{k-1})\exp \left(\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;k\&Delta;ft}\right)$

$=w_T\left(t\right)\underset{k=1}{\overset{N}{\mathrm{\&Sigma;}}}{c}_k\exp \left(\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;k\&Delta;ft}\right)-w_T\left(t\right)\underset{k=1}{\overset{N}{\mathrm{\&Sigma;}}}{c}_{k-1}\exp \left(\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;k\&Delta;ft}\right)---\left(10\right)$

Wherein,

Be single baseband signalling, w _T(t) be window function, identical with formula (2) definition, Δ f is a subcarrier spacing, d _kBe k correlative coding data constantly.For easy analysis, suppose c ₀And c _NBe 0, then Become:

$s_n^{\&prime;}\left(t\right)=w_T\left(t\right)\underset{k=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{c}_k\exp \left(\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;k\&Delta;ft}\right)-w_T\left(t\right)\underset{k=1}{\overset{N}{\mathrm{\&Sigma;}}}{c}_{k-1}\exp \left(\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;k\&Delta;ft}\right)$

$=w_T\left(t\right)\underset{k=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{c}_k\exp \left(\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;k\&Delta;ft}\right)-w_T\left(t\right)\underset{k=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{c}_k\exp \left(\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;}(k+1)\mathrm{\&Delta;ft}\right)$

$=[w_T\left(t\right)-w_T\left(t\right)\exp \left(\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;\&Delta;ft}\right)]\&times;\underset{k=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{c}_k\exp \left(\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;k\&Delta;ft}\right)$

$=w_T^{\&prime;}\left(t\right)\underset{k=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{c}_k\exp \left(\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;k\&Delta;ft}\right)---\left(11\right)$

Time window wherein

Be defined as: $w_T^{\&prime;}\left(t\right)=w_T\left(t\right)\&times;[1-\mathrm{Exp}\left(\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;\; \&Delta;\; Ft}\right)],$

Fourier transform

Can be expressed as:

$W_T^{\&prime;}\left(f\right)=W_T\left(f\right)-W_T(f-\mathrm{\&Delta;f})---\left(12\right)$

With the W that derives and obtain in the prior art _T(f) substitution following formula, for easy analysis, order $\mathrm{\&alpha;}=\frac{\mathrm{Cos}\left(\mathrm{\&pi;}{T}_{\mathrm{TR}}f\right)}{1-4T_{\mathrm{TR}}^2{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">f</figure-callout>}}^2},$ Formula is simplified, can be got:

$W_T^{\&prime;}\left(f\right)=\mathrm{\&alpha;}\&CenterDot;T_s\&times;[\sin c\left(T_{s}f\right)\exp (-\mathrm{j\&pi;}{T}_{s}f)-\sin c\left(T_s(f-\mathrm{\&Delta;f})\right)\exp (-\mathrm{j\&pi;}{T}_s(f-\mathrm{\&Delta;f})]$

$=\mathrm{\&alpha;}\&CenterDot;T_s\&times;\exp (-\mathrm{j\&pi;}{T}_{s}f)[\sin c\left(T_{s}f\right)+\sin c\left(T_s(f-\mathrm{\&Delta;f})\right)]$

$=\mathrm{\&alpha;}\&CenterDot;T_s\&times;\exp (-\mathrm{j\&pi;}{T}_{s}f)\frac{\mathrm{\&Delta;}f\sin \left(\mathrm{\&pi;}{T}_{s}f\right)}{\mathrm{\&pi;}{T}_{s}f(\mathrm{\&Delta;f}-f)}---\left(13\right)$

Thereby can obtain further carrying out that the power spectral density of single sub-carrier waveform is after the correlative coding:

$P_{\mathrm{gk}}^{\&prime;}\left(f\right)=\frac{{\left|W_T^{\&prime;}\left(f\right)\right|}^2}{T_s}\underset{n=\&infin;}{\overset{\&infin;}{\mathrm{\&Sigma;}}}R\left(k\right)\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="e\; j"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">e</figure-callout>}}^j---\left(14\right)$

Relatively formula (14) and (6) can find out that the attenuation outside a channel speed of single sub-carrier frequency spectrum of the prior art is a/f, and the attenuation outside a channel speed of single sub-carrier frequency spectrum has become α/f behind the correlative coding that the embodiment of the invention provides ², explain that correlative coding accelerated the attenuation outside a channel speed of subcarrier.For the technique effect of the embodiment of the invention is described better; As shown in Figure 3 through Computer Simulation; It is the comparison diagram of single sub-carrier frequency spectrum of the present invention and prior art single sub-carrier frequency spectrum; Can find out that the subcarrier main lobe energy behind the correlative coding is more concentrated, secondary lobe leaks also than little before the correlative coding.

The spectral notch position power spectrum that can further obtain behind the correlative coding in conjunction with formula (13) and (14) is:

$\begin{array}{cc}{P}_{\mathrm{notch}}\&prime;\left(f\right)=R_s(\underset{k=0}{\overset{{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">K</figure-callout>}}_1}{\mathrm{\&Sigma;}}}{\left|W_T^{\&prime;}(f-\mathrm{k\&Delta;f})\right|}^2+\underset{k=K_2}{\overset{N-1}{\mathrm{\&Sigma;}}}{\left|W_T^{\&prime;}(f-\mathrm{k\&Delta;f})\right|}^2)& f\&Element;[{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="H2008102194928E00021.png"\; state="\{\{state\}\}">f</figure-callout>}}_1,f_2]\end{array}---\left(15\right)$

With P of the prior art _Notch(f) relatively, can get P _Notch() > f; P _Notch' (f).Need to prove, between step 103 and step 104, also comprise the subcarrier that detection need be closed, and close the transmission of this subcarrier that need close.Can come the definite subcarrier that need close through detecting the plain value of predefined Tone-Nulling entry of a matrix during practical implementation,, then close transmission with the corresponding subcarrier of this element position if said element value is 0.Said predefined each element of Tone-Nulling matrix is represented the position of the corresponding subcarrier of OFDM symbol; Said element value is respectively 0 or 1; Element value is 0 and shows that the subcarrier corresponding with this element value produced interference to narrow-band communication system on the frequency band in the matrix, and can reduce the interference to frequency band (like the frequency band of authorized user) this moment through closing said subcarrier; Element value is 1 and shows that this subcarrier produce to disturb frequency band in the matrix, can send with normal power.Like Fig. 4, be that the present invention and prior art are at the comparison diagram of closing spectral notch under the same band subcarrier situation.Fig. 4 (a), 4 (b), 4 (c) are respectively that sub-band bandwidth is when being 264MHZ; Close the comparison of 5,10,20 sub-carrier bandwidth the present invention and prior art spectral notch; Can find out by figure, under the situation of closing same bandwidth subcarrier, adopt correlative coding can produce darker spectral notch; And along with the increase of the bandwidth of closing, the spectral notch effect is obvious more.Therefore with respect to common MB-OFDM UWB system, the system behind the employing correlative coding produces darker spectral notch than the system that directly closes respective sub.

105, said OFDM symbol is carried out sending after the handled;

Concrete, said OFDM symbol to be handled the back generate packet, said processing comprises and closes leading character behind the subcarrier and merge and generate packet, said leading character includes detections, the thick synchronous information such as channel estimating that reaches.Then said packet is carried out digital to analog conversion and generate base-band analog signal, more said base-band analog signal is carried out sending after the carrier modulation.

Present embodiment generates pre-code data through the data to be sent behind the interweaving encoding being carried out precoding; Said pre-code data is generated mapping (enum) data through the planisphere mapping, then said mapping (enum) data is carried out correlative coding and generate the correlative coding data, at last said correlative coding data are carried out IFFT and generate the OFDM symbol; Said OFDM symbol is carried out sending after the handled; Accelerated the attenuation outside a channel of subcarrier like this through precoding and correlative coding, reduced the band external leakage of subcarrier secondary lobe, made that subcarrier main lobe energy is more concentrated; Thereby can further deepen the spectral notch degree of depth, eliminate interference frequency band

Fig. 5 is a second embodiment of the invention signal processing method flow chart.Specifically may further comprise the steps:

201, the reception data after the Synchronous Processing are generated the correlative coding data through the OFDM demodulation;

Concrete, the data that receive earlier through the carrier wave demodulation of corresponding frequencies, are generated base-band analog signal; Convert said base-band analog signal to baseband digital signal through analog to digital conversion, at last said baseband digital signal is carried out Synchronous Processing and OFDM demodulation, specifically comprise detection, synchronously thick; Frequency offset estimating, phase place is corrected, channel estimating; Synchronously smart, in time, proofread and correct partially, Fourier transform (Fourier Transform; FFT), equilibrium, Phase Tracking etc. are handled and are generated the correlative coding data.

202, said correlative coding data are carried out the correlative coding demodulation and generate corresponding mapping (enum) data;

Concrete, according to following formula said correlative coding data are carried out demodulation and generate corresponding mapping (enum) data:

c _k＝c _k-1+d _k-1 (16)

Wherein, d _K-1Be k-1 correlative coding data constantly, c _K-1K-1 mapping (enum) data constantly, c _kIt is k mapping (enum) data constantly.Said correlative coding demodulating process is the inverse process of step 103 in the first embodiment of the invention.

203, said mapping (enum) data is carried out planisphere mapping demodulation and generate pre-code data.

204, said pre-code data is carried out the precoding demodulation and generate interleaved encoded data;

Concrete, according to following formula said pre-code data is carried out demodulation and generates interleaved encoded data:

$a_k=b_k\&CirclePlus;b_{k-1}---\left(17\right)$

Wherein, b _kBe k pre-code data constantly, b _K-1Be k-1 pre-code data constantly, a _kBe k interleaved encoded data constantly, Be nodulo-2 addition.Said precoding demodulating process is the inverse process of step 101 in the first embodiment of the invention.

205, said interleaved encoded data is carried out demodulation and decoding;

Concrete, with the interleaved encoded data a that generates in the step 204 _kCarry out demodulation and decoding generation information bit data.

Present embodiment is through generating the correlative coding data with the reception data after the Synchronous Processing through the OFDM demodulation; Said correlative coding data are carried out the correlative coding demodulation generate corresponding mapping (enum) data; Then said mapping (enum) data is carried out planisphere mapping demodulation and generate pre-code data; At last said pre-code data is carried out the precoding demodulation and generates interleaved encoded data and said interleaved encoded data is carried out demodulation and decoding, realized like this to receive accordingly from the signal after data receiver precoding and the correlative coding processing, demodulation and decoding processing.

Fig. 6 is a third embodiment of the invention signal processing apparatus structural representation, and said device comprises: precoding module 30, planisphere mapping block 31, correlative coding module 32, OFDM symbol generation module 34 and sending module 35.To specify contact and function between each module below.

Precoding module 30 is used for that the data to be sent behind the interweaving encoding are carried out precoding and generates pre-code data;

Concrete, said precoding module 30 is carried out precoding according to the data to be sent of following formula after to interweaving encoding and is generated pre-code data:

$b_k=a_k\&CirclePlus;b_{k-1}$

Wherein, a _kBe the data to be sent constantly of k behind the interweaving encoding, b _kBe k pre-code data constantly, b _K-1Be k-1 pre-code data constantly, Be nodulo-2 addition.

Planisphere mapping block 31 is used for that the pre-code data that said precoding module generates is carried out the planisphere mapping and generates mapping (enum) data.

Correlative coding module 32 is used for that the mapping (enum) data that said planisphere mapping block generates is carried out correlative coding and generates the correlative coding data;

Concrete, said correlative coding module 32 is carried out correlative coding according to following formula to said mapping (enum) data and is generated the correlative coding data:

d _k＝c _k-c _k-1

Wherein, c _kBe k mapping (enum) data constantly, c _K-1Be k-1 mapping (enum) data constantly, d _kBe k correlative coding data constantly.

OFDM symbol generation module 34 is used for that the correlative coding data that said correlative coding module generates are carried out IFFT and generates corresponding OFDM symbol;

Concrete, between said correlative coding module 32 and OFDM symbol generation module 34, also comprise subcarrier closing module 33, be used to detect the subcarrier that need close, and close the transmission of this subcarrier that need close.During practical implementation, can come the definite subcarrier that need close,, then close transmission with the corresponding subcarrier of this element position if said element value is 0 through detecting the plain value of predefined Tone-Nulling entry of a matrix.Each element of said matrix is represented the position of the corresponding subcarrier of OFDM symbol respectively, and said element value is respectively 0 or 1.Element value is 0 and shows that the subcarrier corresponding with this element value produced interference to frequency band in the matrix, and can reduce the interference to frequency band (like the frequency band of authorized user) this moment through closing said subcarrier; Element value is 1 and shows that this subcarrier produce to disturb frequency band in the matrix, can send with normal power.

Sending module 35 is used for said OFDM symbol is carried out sending after the handled;

Concrete, said sending module 35 is handled the back with said OFDM symbol and is generated packet, and said processing comprises and close leading character behind the subcarrier and merge and generate packet, and said leading character includes detections, the thick synchronous information such as channel estimating that reaches.Then said packet is carried out digital to analog conversion and generate base-band analog signal, more said base-band analog signal is carried out sending after the carrier modulation.

Fig. 6 is a kind of signal processing apparatus structural representation of fourth embodiment of the invention.Said device comprises OFDM demodulation module 40, is used for the reception data after the Synchronous Processing are generated the correlative coding data through the OFDM demodulation; Correlative coding demodulation module 41 is used for that the correlative coding data that said OFDM demodulation module 40 generates are carried out demodulation and generates corresponding mapping (enum) data; Planisphere mapping demodulation module 42 is used for that the mapping (enum) data that said correlative coding demodulation module 41 generates is carried out demodulation and generates pre-code data; Precoding demodulation module 43 is used for the pre-code data demodulation that said planisphere mapping demodulation module 42 generates is generated interleaved encoded data; Decoding module 44 is used for the interleaved encoded data that said precoding demodulation module 43 generates is carried out demodulation and decoding.

Need to prove that the correlative coding data that said correlative coding demodulation module 41 generates said OFDM demodulation module 43 according to following formula are carried out demodulation and generated corresponding mapping (enum) data:

c _k＝c _k-1+d _k-1

Wherein, d _K-1Be k-1 correlative coding data constantly, c _K-1K-1 mapping (enum) data constantly, c _kIt is k mapping (enum) data constantly.

Said precoding demodulation module 43 generates interleaved encoded data according to following formula to the pre-code data demodulation that said planisphere mapping demodulation module 42 generates:

$a_k=b_k\&CirclePlus;b_{k-1}$

Wherein, b _kBe k pre-code data constantly, b _K-1Be k-1 pre-code data constantly, a _kBe k interleaved encoded data constantly, Be nodulo-2 addition.

In sum; A kind of signal processing method that the embodiment of the invention provides and signal processing apparatus generate pre-code data through the data to be sent behind the interweaving encoding being carried out precoding; Said pre-code data is generated mapping (enum) data through the planisphere mapping, then said mapping (enum) data is carried out correlative coding and generate the correlative coding data, at last said correlative coding data are carried out IFFT and generate the OFDM symbol; Said OFDM symbol is carried out sending after the handled; Accelerated the attenuation outside a channel of subcarrier like this through precoding and correlative coding, reduced the band external leakage of subcarrier secondary lobe, made that subcarrier main lobe energy is more concentrated; Thereby can further deepen the spectral notch degree of depth, eliminate interference frequency band.

Above disclosedly be merely a kind of preferred embodiment of the present invention, can not limit the present invention's interest field certainly with this, the equivalent variations of therefore doing according to claim of the present invention still belongs to the scope that the present invention is contained.

Obviously, those skilled in the art can carry out various changes and modification to the present invention and not break away from the spirit and scope of the present invention.Like this, belong within the scope of claim of the present invention and equivalent technologies thereof if of the present invention these are revised with modification, then the present invention also is intended to comprise these changes and modification interior.

Claims (10)

1. a signal processing method is characterized in that, comprising:

Data to be sent behind the interweaving encoding are carried out precoding generate pre-code data;

Said pre-code data is carried out the planisphere mapping generate mapping (enum) data;

Said mapping (enum) data is carried out correlative coding generate the correlative coding data;

Said correlative coding data are carried out inverse fast fourier transform generate the orthogonal frequency division multiplex OFDM symbol;

Said OFDM symbol is carried out sending after the handled;

Wherein, saidly said mapping (enum) data is carried out correlative coding generate the data based following formula of correlative coding and calculate:

d _k＝c _k-c _k-1

Wherein, c _kBe k mapping (enum) data constantly, c _K-1Be k-1 mapping (enum) data constantly, d _kBe k correlative coding data constantly.

2. the method for claim 1 is characterized in that, saidly data to be sent behind the interweaving encoding are carried out precoding generates pre-code data and calculates according to following formula:

$b_k=a_k\&CirclePlus;b_{k-1}$

Wherein, a _kBe the data to be sent constantly of k behind the interweaving encoding, b _kBe k pre-code data constantly, b _K-1Be k-1 pre-code data constantly,

Be nodulo-2 addition.

3. the method for claim 1 is characterized in that, saidly said correlative coding data are carried out IFFT generates the OFDM symbol and calculates according to following formula:

$s_n^{\&prime;}\left(t\right)=w_T\left(t\right)\underset{k=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{d}_k\exp \left(j2\mathrm{\&pi;k\&Delta;ft}\right)$

Wherein, s ' _n(t) be single baseband OFDM symbol, w _T(t) be window function, Δ f is a subcarrier spacing, d _kBe k correlative coding data constantly.

4. the method for claim 1 is characterized in that, said correlative coding data is generated through IFFT between the step of OFDM symbol and also comprises said mapping (enum) data being carried out step and said that correlative coding generates the correlative coding data:

The subcarrier that detection need be closed, and close the transmission of this subcarrier that need close.

5. method as claimed in claim 4 is characterized in that, the subcarrier that said detection need be closed, and the step of closing the transmission of this subcarrier that need close is specially:

Detect the plain value of predefined tone nulling Tone-Nulling entry of a matrix,, then close transmission with the corresponding subcarrier of this element position if said element value is 0.

6. a signal processing apparatus is characterized in that, comprising:

Precoding module is used for that the data to be sent behind the interweaving encoding are carried out precoding and generates pre-code data;

The planisphere mapping block is used for that the pre-code data that said precoding module generates is carried out the planisphere mapping and generates mapping (enum) data;

The correlative coding module is used for that the mapping (enum) data that said planisphere mapping block generates is carried out correlative coding and generates the correlative coding data;

OFDM symbol generation module is used for that the correlative coding data that said correlative coding module generates are carried out IFFT and generates corresponding OFDM symbol;

Sending module is used for said OFDM symbol is carried out sending after the handled;

Wherein, saidly said mapping (enum) data is carried out correlative coding generate the data based following formula of correlative coding and calculate:

d _k＝c _k-c _k-1

Wherein, c _kBe k mapping (enum) data constantly, c _K-1Be k-1 mapping (enum) data constantly, d _kBe k correlative coding data constantly.

7. device as claimed in claim 6 is characterized in that, between said correlative coding module and said OFDM symbol generation module, also comprises:

The subcarrier closing module is used to detect the subcarrier that need close, and closes the transmission of this subcarrier that need close.

8. a signal processing method is characterized in that, comprising:

Reception data after the Synchronous Processing are generated the correlative coding data through the OFDM demodulation;

Said correlative coding data are carried out the correlative coding demodulation generate corresponding mapping (enum) data;

Said mapping (enum) data is carried out planisphere mapping demodulation generate pre-code data;

Said pre-code data is carried out the precoding demodulation generate interleaved encoded data;

Said interleaved encoded data is carried out demodulation and decoding;

Wherein, saidly said correlative coding data are carried out the correlative coding demodulation generate corresponding mapping (enum) data and specifically calculate according to following formula:

c _k＝c _k-1+d _k-1

Wherein, d _K-1Be k-1 correlative coding data constantly, c _K-1K-1 mapping (enum) data constantly, c _kIt is k mapping (enum) data constantly.

9. method as claimed in claim 8 is characterized in that, saidly said pre-code data is carried out the precoding demodulation generates interleaved encoded data and specifically calculates according to following formula:

$a_k=b_k\&CirclePlus;b_{k-1}$

Wherein, b _kBe k pre-code data constantly, b _K-1Be k-1 pre-code data constantly, a _kBe k interleaved encoded data constantly,

Be nodulo-2 addition.

10. a signal processing apparatus is characterized in that, comprising:

The OFDM demodulation module is used for the reception data after the Synchronous Processing are generated the correlative coding data through the OFDM demodulation;

The correlative coding demodulation module is used for that the correlative coding data that said OFDM demodulation module generates are carried out demodulation and generates corresponding mapping (enum) data;

Planisphere mapping demodulation module is used for that the mapping (enum) data that said correlative coding demodulation module generates is carried out demodulation and generates pre-code data;

The precoding demodulation module is used for the pre-code data demodulation that said planisphere mapping demodulation module generates is generated interleaved encoded data;

Decoding module is used for the interleaved encoded data that said precoding demodulation module generates is carried out demodulation and decoding;

Wherein, saidly said correlative coding data are carried out demodulation generate corresponding mapping (enum) data and specifically calculate according to following formula:

c _k＝c _k-1+d _k-1

Wherein, d _K-1Be k-1 correlative coding data constantly, c _K-1K-1 mapping (enum) data constantly, c _kIt is k mapping (enum) data constantly.

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