CN102420790A - Equalization processing method in single carrier ultra wide band communication system and system thereof - Google Patents

Abstract

The invention provides an equalization processing method in a single carrier ultra wide band communication system. The method comprises the following steps: a multiplier multiplies input data and local carrier wave recovered by a mapping device to obtain data whose carrier wave frequency offset is eliminated, and the data is input into an equalizer; the equalizer carries out eliminating intersymbol interference processing on the data, and inputs obtained data into a phase discriminator; the phase discriminator extracts a phase error of the data relative to data in a constellation graph, and inputs the phase error into a loop filter; according to the phase error, the loop filter calculates a phase pushing figure of the local carrier wave relative to an actual sending carrier wave, and inputs the phase pushing figure into an accumulator; according to the phase pushing figure, the accumulator carries out accumulation to obtain a local carrier wave phase which is inputted into the mapping device; according to the local carrier wave phase, the mapping device recovers the local carrier wave, and inputs the local carrier wave to the multiplier.

Description

Equalization processing method and system in a kind of single-carrier and ultra-wideband communication system

Technical field

The application relates to the equilibrium treatment technical field, particularly relates to equalization processing method and system in a kind of single-carrier and ultra-wideband communication system.

Background technology

Single-carrier and ultra-wideband (SC-UWB) technology is a kind of short-distance wireless communication technology; Multi-band orthogonal frequency division multiplexing (MB-OFDM) technology with respect to present ultra broadband (UWB) main flow; SC-UWB not only satisfies requirement at a high speed; Also overcome the high peak-to-average force ratio of MB-OFDM, to the demanding shortcoming of timing frequency deviation, help singualtion and realize.

In the modulation system of digital signal, quadriphase PSK (QPSK) is present the most frequently used a kind of satellite digital signal modulation system, and it has the higher availability of frequency spectrum, stronger anti-interference, on circuit, realizes also comparatively simple.The quaternary phase shift modulation is to utilize four kinds of out of phase differences of carrier wave to characterize the digital information of input, is quaternary phase-shift keying.Each modulation can be transmitted 2 information bits among the QPSK, and these information bits are to transmit through four kinds of phase places of carrier wave, and demodulator is judged the information bit that transmitting terminal sends according to the phase place of planisphere and the carrier signal that receives.

The characteristics of SC-UWB system are that very bandwidth is wide, though adopt optimum RAKE receiver that the rake gain is provided, but still can't solve the serious intersymbol interference (ISI) that UWB channel multi-path dense, long delay bring fully.Therefore, after RAKE receiver, must carry out high performance equilibrium treatment, in order to influence and the elimination intersymbol interference that overcomes carrier wave frequency deviation.

Common equalization processing method is to carry out carrier wave earlier to recover to eliminate carrier wave frequency deviation; Eliminate intersymbol interference again and handle, but when in the SC-UWB system, adopting the QPSK modulation, because the existence of intersymbol interference; Carrier wave recovers to be difficult to convergence; Thereby cause system's losing lock, can't eliminate carrier wave frequency deviation, and then can not eliminate intersymbol interference smoothly and handle.Therefore, existing equalization processing method can't satisfy the demand of high-performance treatments in the SC-UWB system.

Summary of the invention

The application's technical problem to be solved provides equalization processing method and the system in a kind of single-carrier and ultra-wideband communication system, can overcome the influence of intersymbol interference and carrier wave frequency deviation simultaneously, realizes high performance equilibrium treatment.

In order to address the above problem, the application discloses the equalization processing method in a kind of single-carrier and ultra-wideband communication system, comprising:

Multiplier will be imported the local carrier that data and mapper recover and multiply each other the data of the carrier wave frequency deviation that is eliminated, input equalizer;

Equalizer is eliminated intersymbol interference to the data of said elimination carrier wave frequency deviation and is handled, with the data input phase discriminator that obtains;

Phase discriminator extracts data that said equalizer the obtains phase error with respect to data in the planisphere, input loop filter;

Loop filter is according to the phase pushing figure of said phase error computation local carrier with respect to reality transmission carrier wave, input accumulator;

Accumulator adds up according to said phase pushing figure and obtains the local carrier phase place, the input mapper;

Mapper recovers local carrier according to said local carrier phase place, with said local carrier input multiplier.

Preferably, said equalizer is the multidiameter delay equalizer.

Preferably, described method also comprises:

Equalizer exports the said data that obtain to outer decoder.

Preferably, if said phase pushing figure for just, then the phase place of local carrier is sent the phase place of carrier wave less than reality;

If said phase pushing figure is for negative, then the phase place of local carrier is sent the phase place of carrier wave greater than reality.

On the other hand, disclosed herein as well is the equilibrium treatment system in a kind of single-carrier and ultra-wideband communication system, comprising:

Multiplier unit is used for input data and the local carrier that recovers are multiplied each other, the data of the carrier wave frequency deviation that is eliminated, input multidiameter delay equalizer unit;

Equalizer unit is used for that the data of said elimination carrier wave frequency deviation are eliminated intersymbol interference and handles, with the data input phase discriminator unit that obtains;

The phase discriminator unit is used for extracting data that said equalizer the obtains phase error with respect to the planisphere data, the input loop filter unit;

Loop filter unit is used for according to the phase pushing figure of said phase error computation local carrier with respect to reality transmission carrier wave, input accumulator;

Accumulator element, being used for adding up according to said phase pushing figure obtains the local carrier phase place, input mapper unit;

The mapper unit is used for recovering local carrier according to said local carrier phase place, with said local carrier input multiplier unit.

Preferably, said equalizer is the multidiameter delay equalizer.

Preferably, described system also comprises:

Output unit is used for exporting the data that said equalizer unit obtains to outer decoder.

Preferably, if said phase pushing figure for just, then the phase place of local carrier is sent the phase place of carrier wave less than reality;

If said phase pushing figure is for negative, then the phase place of local carrier is sent the phase place of carrier wave greater than reality.

Compared with prior art, the application comprises following advantage:

The first, the application adopts the structure of carrier wave recovery and self-adaptive parallel balancing combine loop, and each clock at first will be imported data and the carrier multiplication that recovers, and the input data are carried out the elimination of phase deviation, thereby eliminates the influence of carrier wave frequency deviation; And then send into parallel equalizer, go intersymbol interference to handle; Obtain of the final output of pure signal like this, also be used for extracting simultaneously current carrier phase error, this signal is carried out carrier wave recover, carrier wave that recovers and input data are multiplied each other as the associating loop.Whole process constitutes a loop, and this equalization processing method can overcome the influence of intersymbol interference and carrier wave frequency deviation simultaneously, satisfies the demand of high-performance equilibrium treatment.

Second; Equalizer adopts multidiameter delay self-adaptive linear equalisation device among the application; Thereby adaptive process is used for dynamically estimating the variation of wireless channel and eliminates intersymbol interference; Equalizer has adopted the structure of multidiameter delay simultaneously, can satisfy the requirement of equilibrium treatment high-throughput in single-carrier and ultra-wideband (SC-UWB) system.

Description of drawings

Fig. 1 is the flow chart of steps of the equalization processing method in a kind of single-carrier and ultra-wideband communication system of the application;

Fig. 2 is the structural representation of the loop filter that equalization processing method adopted in a kind of single-carrier and ultra-wideband communication system of the application;

Fig. 3 uses the application the characteristic curve of error code that test obtains under the view distance environment is being arranged;

Fig. 4 uses the application the carrier phase curve that obtains under the carrier wave frequency deviation of 10PPM is being arranged;

Fig. 5 is the equilibrium treatment system construction drawing in a kind of single-carrier and ultra-wideband communication system of the application.

Embodiment

For above-mentioned purpose, the feature and advantage that make the application can be more obviously understandable, the application is done further detailed explanation below in conjunction with accompanying drawing and embodiment.

The application is primarily aimed at when adopting the QPSK modulation system in the single-carrier and ultra-wideband communication system it is carried out equilibrium treatment.Adopt the structure of carrier wave recovery and self-adaptive parallel balancing combine loop, be used to satisfy the specific (special) requirements of single-carrier and ultra-wideband (SC-UWB) communication system.Each clock at first carries out the elimination of carrier wave frequency deviation to input signal, and then goes intersymbol interference to handle, and obtains the final output of pure signal as the associating loop like this, also is used for extracting simultaneously current carrier phase error.This equaliser structure can satisfy the throughput and the high performance demands of expection, and complexity is not high yet, is fit to realize with ASIC.

The application is positioned at RAKE receiver in single-carrier and ultra-wideband (SC-UWB) communication system after, before the Viterbi decoding.Receive the data after RAKE merges, dynamically carry out carrier track and eliminate intersymbol interference, then data are sent into decoder and decipher output.

With reference to Fig. 1, show the flow chart of steps of the equalization processing method in a kind of single-carrier and ultra-wideband communication system of the application, comprising:

Step 101, multiplier will be imported the local carrier that data and mapper recover and multiply each other the data of the carrier wave frequency deviation that is eliminated, input equalizer;

Step 102, equalizer is eliminated intersymbol interference to the data of said elimination carrier wave frequency deviation and is handled, with the data input phase discriminator that obtains;

Equalizer among the application adopts multidiameter delay linear adaptive equalizer device; Adaptive process is used for estimating dynamically the variation of wireless channel; Thereby elimination intersymbol interference; Adopt the multidiameter delay structure to improve the throughput of system simultaneously, and the multidiameter delay equaliser structure adopts the low method for designing that postpones, guaranteed the convergence of whole loop.

Equalizer adopts time domain linear balanced, and adaptive algorithm adopts lowest mean square (LMS) algorithm, for the renewal equation of serial LMS algorithm is:

$\left\{\begin{array}{c}y\left(n\right)={\stackrel{\‾}{W}}^T\left(n\right)\stackrel{\‾}{U}\left(n\right)\\ e\left(n\right)=d\left(n\right)-y\left(n\right)\\ \stackrel{\‾}{W}(n+1)=\stackrel{\‾}{W}\left(n\right)+\mathrm{\μe}(n-1)\stackrel{\‾}{U}(n-1)\end{array}\right.$

Wherein, W (n) is an equalizer coefficients, and U (n) is the input data, and d (n) is tutor's sequence, and e (n) is an error sequence, and μ is an iteration step length, and y (n) is an output sequence.

For multichannel (for example L road) parallel processing mode, each clock need be handled L symbol, therefore, is easy to obtain L road parallel algorithm renewal equation and is:

$\left\{\begin{array}{c}y\left(\mathrm{Ln}\right)={\stackrel{\‾}{W}}^H\left(\mathrm{Ln}\right)\stackrel{\‾}{U}\left(\mathrm{Ln}\right)\\ y(\mathrm{Ln}+1)={\stackrel{\‾}{W}}^H\left(\mathrm{Ln}\right)\stackrel{\‾}{U}(\mathrm{Ln}+1)\\ \·\·\·\\ y(\mathrm{Ln}+L-1)={\stackrel{\‾}{W}}^H\left(\mathrm{Ln}\right)\stackrel{\‾}{U}(\mathrm{Ln}+L-1)\\ e\left(\mathrm{Ln}\right)=d\left(\mathrm{Ln}\right)-y\left(\mathrm{Ln}\right)\\ e(\mathrm{Ln}+1)=d(\mathrm{Ln}+1)-y(\mathrm{Ln}+1)\\ \·\·\·\\ e(\mathrm{Ln}+L-1)=d(\mathrm{Ln}+L-1)-y(\mathrm{Ln}+L-1)\\ \stackrel{\‾}{W}(\mathrm{Ln}+L)=\stackrel{\‾}{W}\left(\mathrm{Ln}\right)+{\mathrm{\μe}}^{*}(\mathrm{Ln}-L)\stackrel{\‾}{U}(\mathrm{Ln}-L)\\ +\·\·\·+{\mathrm{\μe}}^{*}(\mathrm{Ln}-1)\stackrel{\‾}{U}(\mathrm{Ln}-1)\end{array}\right.$

Wherein, W (n) is an equalizer coefficients, and U (n) is the input data, and d (n) is tutor's sequence, and e (n) is an error sequence, and u is an iteration step length, and y (n) is an output sequence.

Simultaneously, equalizer also with the dateout of the data that obtain as whole loop, exports outer decoder to and deciphers.

Step 103, phase discriminator are extracted data that said equalizer the obtains phase error with respect to data in the planisphere, input loop filter;

Two basic parameters have been defined in the planisphere of QPSK modulation: (1) signal distributions; (2) and the mapping relations between the modulation digital bit.Stipulated the corresponding relation between constellation point and transmitted bit in the planisphere, this relation is called " mapping ", and a kind of characteristic of modulation technique can be come to define fully by signal distributions and mapping definition fully by planisphere.

For the parallelization of carrier recovery loop, key is to extract phase error, and the phase error that the application's phase discriminator adopts is extracted equation and is:

Δθ＝f(y)

＝-sgn(real(y))×sgn(imag(y))

×sgn(real(y)+imag(y))

×sgn(real(y)-imag(y))

Wherein, y is the input data of phase discriminator, and Δ θ is the phase demodulation error.

For the parallel input in L road, the error extracting equation that we are easy to obtain under the parallel situation is:

Δθ＝f(y(Ln))+f(y(Ln+1))+…+f(y(Ln+L-1))

Wherein, y (i) is the equalizer output on i road, i=Ln ... Ln+L-1, Δ θ are the phase demodulation errors.

Step 104, loop filter is according to the phase pushing figure of said phase error computation local carrier with respect to reality transmission carrier wave, input accumulator;

If said phase pushing figure is for just, then the phase place of local carrier is sent the phase place of carrier wave less than reality;

If said phase pushing figure is for negative, then the phase place of local carrier is sent the phase place of carrier wave greater than reality.

With reference to Fig. 2, show the structural representation of the loop filter that equalization processing method adopted in a kind of single-carrier and ultra-wideband communication system of the application, wherein, COEFFICIENT K _PWith K _iBe two key coefficients of loop filter, determined the speed and the precision of carrier track.K _P, K _iBig more, then tracking is fast more, but precision is low more.

Step 105, accumulator add up according to said phase pushing figure and obtain the local carrier phase place, the input mapper;

Step 106, mapper recovers local carrier according to said local carrier phase place, with said local carrier input multiplier.

Whole equalization process constitutes a loop; Having guaranteed to send into equalizer, to eliminate data that intersymbol interference handles be to recover to eliminate the data after the carrier wave frequency deviation through carrier wave; Sending into the carrier wave restoration path simultaneously, to carry out the carrier wave data recovered be to eliminate the data after the intersymbol interference through equalizer, guaranteed that carrier wave recovers and blanking code between normally the carrying out of interfering process.Through circular treatment constantly, make whole equalization process reach high performance demand, utilize the multidiameter delay equalizer simultaneously, also satisfied the requirement of system's high-throughput.

With reference to Fig. 3, showing application the application is having the characteristic curve of error code that test obtains under the view distance environment.Wherein, the line of band round dot is represented the RAKE receptivity, and the line of band circle is represented equalizer performance, representes to decipher performance afterwards with tetragonal line, representes the theoretical error code curve of QPSK with leg-of-mutton line.

As can be seen from the figure, because the influence of carrier deviation, the RAKE output error rate is 50%.But through after the equalizer, carrier deviation and ISI have all obtained elimination, and performance has had obvious improvement.Along with the increase of signal to noise ratio, the error rate is obvious downward trend, and folding coding has obtained tangible coding gain, under 10dB, can obtain to be superior to 10 ^-5Error performance.

Below, with a concrete case introduction the application's the course of work, what the applied SC-UWB of the application system adopted is the modulation system of QPSK, and therefore the data of input are plural numbers, and corresponding in the actual circuit just has I and Q two paths of data.

The form of input data comprises training sequence and data segment, and the data number of training sequence is 400, and each data all is a plural number, and the value of real part and imaginary part representes with 8bit that all value is 32 or-32, and data segment is the real data that receives.In real system, because the fluctuating of the data amplitude after the RAKE maybe be bigger, therefore also be necessary to increase digital Auto Gain control (AGC) module, the dateout amplitude is controlled at about 32.

Carrier wave of the present invention recovers with the initial condition of adaptive equalization associating loop: adaptive equalizer is with two-way and behavior example; Tap coefficient is [00000000100000000]; The original carrier phase place is provided by prime capturing carrier module; Also can be set to 0, two key parameter K of loop filter _PBe taken as 64, K _iBe taken as 1.System adopts the modulation system of QPSK, and the carrier wave frequency deviation of 10PPM is being arranged, and has under the situation of channel of sighting distance to work.

At first treated length is 400 training sequence, and training sequence is one section known array, makes the coefficient of adaptive equalizer converge to one than stable status, and carrier recovery loop also obtains a carrier phase more accurately; After system is in a metastable state; Just begin to handle the real data section, because wireless channel is dynamically, therefore; When process segments of data; Adaptive equalizer still can be finely tuned tap coefficient always, the constantly balanced channel that is changing, and carrier tracking loop is followed the tracks of carrier phase always.Concrete equalization process is by the agency of in the above, and the application discusses at this no longer in detail.

With reference to Fig. 4, showing application the application is having the carrier phase curve that obtains under the carrier wave frequency deviation of 10PPM.Because carrier wave has the carrier wave frequency deviation of 10PPM, therefore, the carrier phase that carrier tracking loop obtains is linear.

Embodiment is corresponding with preceding method, and the application also provides the equilibrium treatment system in a kind of single-carrier and ultra-wideband communication system, with reference to Fig. 5, specifically can comprise:

Multiplier unit is used for input data and the local carrier that recovers are multiplied each other, the data of the carrier wave frequency deviation that is eliminated, input multidiameter delay equalizer unit;

Equalizer unit is used for that the data of said elimination carrier wave frequency deviation are eliminated intersymbol interference and handles, with the data input phase discriminator unit that obtains;

Wherein, said equalizer adopts the multidiameter delay equalizer, in order to improve the throughput of system.

The phase discriminator unit is used for extracting data that said equalizer the obtains phase error with respect to the planisphere data, the input loop filter unit;

Loop filter unit is used for according to the phase pushing figure of said phase error computation local carrier with respect to reality transmission carrier wave, input accumulator;

If said phase pushing figure is for just, then the phase place of local carrier is sent the phase place of carrier wave less than reality;

If said phase pushing figure is for negative, then the phase place of local carrier is sent the phase place of carrier wave greater than reality.

Accumulator element, being used for adding up according to said phase pushing figure obtains the local carrier phase place, input mapper unit;

The mapper unit is used for recovering local carrier according to said local carrier phase place, with said local carrier input multiplier unit.

Also comprise:

Output unit is used for exporting the data that said equalizer unit obtains to outer decoder.

Native system is positioned at RAKE in the single-carrier and ultra-wideband system after, before the Viterbi decoding, receive the data after RAKE merges, dynamically carry out carrier track and eliminate intersymbol interference, then data are sent into decoder and decipher output.

For system embodiment, because it is similar basically with method embodiment, so description is fairly simple, relevant part gets final product referring to the part explanation of method embodiment.

More than to equalization processing method and system in a kind of single-carrier and ultra-wideband communication system that the application provided; Carried out detailed introduction; Used concrete example among this paper the application's principle and execution mode are set forth, the explanation of above embodiment just is used to help to understand the application's method and core concept thereof; Simultaneously, for one of ordinary skill in the art, according to the application's thought, the part that on embodiment and range of application, all can change, in sum, this description should not be construed as the restriction to the application.

Claims (8)

1. the equalization processing method in the single-carrier and ultra-wideband communication system is characterized in that, comprising:

Multiplier will be imported the local carrier that data and mapper recover and multiply each other the data of the carrier wave frequency deviation that is eliminated, input equalizer;

Equalizer is eliminated intersymbol interference to the data of said elimination carrier wave frequency deviation and is handled, with the data input phase discriminator that obtains;

Phase discriminator extracts data that said equalizer the obtains phase error with respect to data in the planisphere, input loop filter;

Loop filter is according to the phase pushing figure of said phase error computation local carrier with respect to reality transmission carrier wave, input accumulator;

Accumulator adds up according to said phase pushing figure and obtains the local carrier phase place, the input mapper;

Mapper recovers local carrier according to said local carrier phase place, with said local carrier input multiplier.

2. method according to claim 1 is characterized in that, said equalizer is the multidiameter delay equalizer.

3. method according to claim 1 is characterized in that, also comprises:

Equalizer exports the said data that obtain to outer decoder.

4. method according to claim 1 is characterized in that,

If said phase pushing figure is for just, then the phase place of local carrier is sent the phase place of carrier wave less than reality;

If said phase pushing figure is for negative, then the phase place of local carrier is sent the phase place of carrier wave greater than reality.

5. the equilibrium treatment system in the single-carrier and ultra-wideband communication system is characterized in that, comprising:

Multiplier unit is used for input data and the local carrier that recovers are multiplied each other, the data of the carrier wave frequency deviation that is eliminated, input multidiameter delay equalizer unit;

Equalizer unit is used for that the data of said elimination carrier wave frequency deviation are eliminated intersymbol interference and handles, with the data input phase discriminator unit that obtains;

The phase discriminator unit is used for extracting data that said equalizer the obtains phase error with respect to the planisphere data, the input loop filter unit;

Loop filter unit is used for according to the phase pushing figure of said phase error computation local carrier with respect to reality transmission carrier wave, input accumulator;

Accumulator element, being used for adding up according to said phase pushing figure obtains the local carrier phase place, input mapper unit;

The mapper unit is used for recovering local carrier according to said local carrier phase place, with said local carrier input multiplier unit.

6. system according to claim 5 is characterized in that, said equalizer is the multidiameter delay equalizer.

7. system according to claim 5 is characterized in that, also comprises:

Output unit is used for exporting the data that said equalizer unit obtains to outer decoder.

8. system according to claim 5 is characterized in that,

If said phase pushing figure is for just, then the phase place of local carrier is sent the phase place of carrier wave less than reality;

If said phase pushing figure is for negative, then the phase place of local carrier is sent the phase place of carrier wave greater than reality.

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