CN1969520A - Noise power estimate based equalizer lock detector - Google Patents

Abstract

An ATSC (Advanced Television Systems Committee-Digital Television) receiver comprises an equalizer (220) and a lock detector (230). The equalizer (220) provides a sequence of received signal points (221) from a constellation space, the constellation space having an inner region and one, or more, outer regions. The lock detector (230) determines equalizer lock as a function of a noise power estimate developed from the number of received signal points falling in the one, or more, outer regions (305).

Description

Equalizer lock detector based on the noise power estimation

Technical field

The present invention relates generally to communication system, relate more specifically to receiver.

Background technology

In picture ATSC-DTV (Advanced Television Systems Committee-Digital Television) system (for example, referring to United States advanced television systems committee, the file A/53 in September 16 nineteen ninety-five " ATSC DigitalTelevision Standard " (" ATSC digital television standard "), file A/54 " Guide to the Use of the ATSC Digital Television Standard " (" ATSC digital television standard guide for use ") with October 4 nineteen ninety-five) in the modern digital communication systems, uses advanced modulation, chnnel coding and equilibrium usually.In receiver, the equalizer processes received signal is so that correcting distortion and its generally are DFE (decision zeedback equalizer) type or its certain variant.

In order to determine whether suitably balanced received signal of equalizer, promptly equalizer whether restrained or " locking " on received signal, typically this receiver comprises " lock detector ".If lock detector indication equalizer is convergence or not locking not, so receiver may, for example reset equalizer and again enabling signal obtain.

Unfortunately, conventional equalizer lock detection methods may produce wrong lock-in detection like this to noise-sensitive, and the lock-in detection of mistake further influences whole receiver performance.

Summary of the invention

We observe, and the The statistical properties of the noise type by considering to appear at for example Additive White Gaussian Noise on the channel might further improve the accuracy of equalizer lock detection, especially in low signal-to-noise ratio (SNR) environment.Particularly, according to the principle of the invention, receiver determines that noise power estimates to be confirmed as the function of the distribution of received signal points in the constellation space as the equalizer lock of the function of noise power estimation, the different weights value is provided wherein for the zones of different of constellation space.

In embodiments of the present invention, the ATSC receiver comprises equalizer and lock detector.Equalizer provides the received signal point sequence from constellation space, and constellation space has interior zone and one or more perimeter.Lock detector determines that it is to obtain (develop) from a plurality of received signal points that drop in one or more perimeters that noise power is estimated as the equalizer lock of the function of noise power estimation.

In another embodiment of the present invention, the ATSC receiver comprises equalizer and lock detector.Equalizer provides the received signal point sequence from constellation space, and constellation space has interior zone and one or more perimeter.Lock detector determines that power signal-to-noise ratio is to obtain from a plurality of received signal points that drop in one or more perimeters as the equalizer lock of the function of power signal-to-noise ratio.

Description of drawings

Fig. 1 and 2 illustrates the received signal probability-distribution function of different noise power grades;

Fig. 3 shows the illustrative high-level block diagram of the receiver of specializing the principle of the invention;

Fig. 4 shows the illustrative part of the receiver of specializing the principle of the invention;

Fig. 5 and 6 shows the illustrative flow according to the principle of the invention;

Fig. 7 further illustrates the present invention's design for the one dimension symbol constellations;

Fig. 8 and 9 further illustrates the present invention's design for the bidimensional symbol constellations;

Figure 10 and 11 shows other illustrative flow according to the principle of the invention;

Figure 12 shows another illustrative embodiment according to the principle of the invention.

Embodiment

Except the present invention's design, element as shown in the figure all is well-known, and will not be described in detail.In addition, suppose broadcasting of people's familiar with television and receiver, and also be not described in detail at this.For example, except the present invention's design, suppose the television standard of the current and proposed recommendations of the familiar picture of people NTSC (national television system committee), PAL (Phase Alternate Line), SECAM (order transmits colored and storage standard) and ATSC (Advanced Television Systems Committee's standard).Equally, except the present invention's design, suppose that people are familiar with for example transmission notion of 8 grades of residual sidebands (8-VSB), quadrature amplitude modulation (qam), with the receiver parts of radio frequency (RF) front end for example, or the receiver part of low noise block, tuner, demodulator, correlator, leaky integrating device and squarer for example.Similarly, it also is well-known being used to produce format and the coding method (for example, Motion Picture Experts Group (MPEG)-2 system standard (ISO/IEC 13818-1)) of transmitting bit stream, and does not describe at this.Should also be noted that the present invention conceives can utilize traditional programming technique to realize, same, does not also describe at this.At last, same numbers is represented similar components among the figure.

Suppose AWGN (Additive White Gaussian Noise) transmission channel, the demodulated received signal can be expressed as in digital communication:

r(nT)＝s(nT)+w(nT)；n＝0，1，2，3…… (1)

Wherein T is the sampling time, and s (nT) is a transmitted symbol, and w (nT) is the Additive White Gaussian Noise of channel.As known in the art, the definition Gaussian Profile is:

$f\left(x\right)={\frac{1}{\mathrm{\σ}\sqrt{2\mathrm{\π}}}e}^{\_{(x-\mathrm{\μ})}^2/2{\mathrm{\σ}}^2}---\left(2\right)$

σ wherein ²Be that variance and μ are mean value.If I and Q add up independently, so top expression formula is applicable on I (homophase) and two kinds of data of Q (quadrature).

Now,, consider reflector for simply, the code element that this reflector emission is taken out from the constellation space that comprises four code element: A, B, C and D, and give each symbol allocation value-3 ,-1,1 and 3 respectively.The dissimilar influences to this transmission signals of awgn channel have been shown among Fig. 1 and 2.Particularly, at the different value (variance) of noise power, these illustrate the probability of outcome distribution function (pdf) of demodulated received signal r (nT).

At first forward Fig. 1 to, the figure shows for σ ²The demodulated received signal pdf of=0.5 noise power.As the shorter solid vertical line of Fig. 1 of representing with line 51 is that illustrative slice (slice) border of receiver is so that " section (slice) " demodulated received signaling point and therefore determine receiving symbol.Mode as known in the art, receiver are carried out section (being also referred to as " hard decoder ") so that select in fact may transmit what code element.Usually, on how much of the section value of the being chosen in aspects near the code element of received signal points as receiving symbol.Under Fig. 1 background, carry out section according to following rule:

S _SlicedIf=-3 r＜-2 have received code element A

If-1-2=＜r＜0 has received code element B

If 10＜=r＜2 have received code element C, and

If 3 r＞2 have received code element D

Wherein, r is the received signal points value and the S of (comprising because any information that noise causes is damaged (corruption)) _SlicedBe to select code element accordingly.For example, if received signal points has value (2.5), receiver will select code element A as receiving symbol so.Can observe from Fig. 1, noise power is can be inapparent, so slice of data is almost always correct, i.e. the code element of corresponding actual transmission always almost.

Yet Fig. 2 has illustrated the influence of bigger noise power to transmission signals.Particularly, Fig. 2 shows for σ ²The demodulated received signal pdf of=3.0 noise power.Once more, Fig. 2 also shows the slice boundaries as line 51 expressions.Should observe now, noise power is enough big, makes some demodulated received signaling point cross the determinating area of another code element.This causes receiver to make slicer error.For example, suppose that once more received signal points has value (2.5).In this case, as before, receiver will select code element A as receiving symbol.But the probability of this section decision error is higher now.Arrow 52 as Fig. 2 is indicated, and the shadow region shows owing to the probability that has transmitted code element B rather than code element A is remarkable, so receiver may be made slicer error.These slicer errors or decision errors may cause the communication chain of low reliability, and cause the communication chain failure in some cases.

We have been noted that by considering to appear at the above-mentioned The statistical properties of the noise type (for example, Additive White Gaussian Noise) on the channel, might further improve the accuracy of equalizer lock detection, especially in low signal-to-noise ratio (SNR) environment.Particularly, we observe from Fig. 2, and the demodulated received signaling point can not be crossed over two or more slice boundaries.For example, misread and be interpreted as code element C or code element D even the transmit symbol A that is damaged by noise also can not be received device.Therefore, we further observe, and compare with the interior zone of constellation space, and receiver is less in the perimeter of constellation space may make mistakes.For example, in Fig. 2 in the determinating area of code element A, even there is the probability of in fact having launched code element B, receiver is still judged and has been received code element A.On the contrary, consider the determinating area of inner code element C.Here, the receiver judgement has received code element C, but may in fact transmit two other code element B or D.Like this, under the background of Fig. 2, externally receiver is less may make mistakes for symbol region (that is, wherein r≤-3 and r 〉=3).

Consider top situation, receiver is less those zones or the part zone that should operate of equalizer lock detector just of may makeing mistakes.Therefore, according to the principle of the invention, receiver determines that noise power estimates to be confirmed as the function of the distribution of received signal points in the constellation space as the equalizer lock of the function of noise power estimation, the different weights value is provided wherein for the zones of different of constellation space.

High-level block diagram according to the illustrative television equipment 10 of the principle of the invention has been shown among Fig. 3.TV (TV) device 10 comprises receiver 15 and display 20.Illustrative ground, receiver 15 are the compatible receivers of ATSC.Merit attention, receiver 15 also may be that NTSC (national television system committee) is compatible, promptly has NTSC operator scheme and ATSC operator scheme, makes TV device 10 can show the video content from NTSC broadcasting or ATSC broadcasting.For simple in describing the present invention's design, the ATSC operator scheme is described at this.Receiver 15 receiving broadcast signals 11 (for example, via the antenna (not shown)) are handled so that be used to be applied on the display 20 from its recovery, and HDTV (high definition TV) vision signal for example is so that watch video content thereon.

With reference now to Fig. 4,, Fig. 4 shows the illustrative embodiment according to the part 200 of the receiver 15 of the principle of the invention.Part 200 comprises antenna 201, radio frequency (RF) front end 205, modulus (A/D) transducer 210, demodulator 215, equalizer 220, food slicer 225, equalizer mode element 230 and error generator 235.Except the present invention's design, the function of various elements shown in Figure 4 is well-known, and will only do concise and to the point the description at this.In addition, be used to adjust the special algorithm of the equalizer coefficients (not shown) of equalizer 220, for example, least fibre method (LMS), constant are asked modulus method (CMA) and simplified constellation algorithm (RCA) all is known in the prior art, and does not describe at this.

The signal that RF front end 205 down conversions and filtering receive via antenna 201 is so that provide nearly baseband signal for A/D converter 210, and the signal of A/D converter 210 sampling down conversions is so that become conversion of signals numeric field and sample sequence 211 is provided for demodulator 215.The automatic gain that is used for restituted signal 211 that demodulator 215 comprises is as known in the art controlled (AGC), symbol timing recovery (STR), carrier tracking loop (CTL) and other functional block so that restituted signal 216 is provided for equalizer 220, the signal point sequence in the restituted signal 216 expression constellation space.Equalizer 220 is handled restituted signals 211 so that proofread and correct the distortion that inter symbol interference (ISI) for example waits, and provides equalizing signal 221 to food slicer 225, balanced mode unit 230 and error generator 235.Food slicer 225 receives equalizing signal 221 (it represents the signal point sequence in the constellation space once more) and makes the hard decision (as mentioned above) about receiving symbol so that provide the sliced symbol sequence via the signal 226 that occurs by chip rate 1/T.Signal 226 is received other parts (not shown) of device 15 and handles, for example the equalizer mode element 230 of forward error recovery (FEC) element and Fig. 4 and error generator 235.As known in the art, error generator 235 produces one or more error signals 236, and for example these error signals are used for proofreading and correct filter (tap) coefficient value that the timing of demodulator 215 is fuzzy and be used to adjust or regulate equalizer 220.For example, error generator 235 measurement equalized signal points and difference between the sliced symbol or error in some cases separately, this difference or error are used to adjust the filter coefficient of equalizer 220.As error generator 235, equalizer mode element 230 also receives equalized signal points and sliced symbol separately respectively via signal 221 and 226.Equalizer mode element 230 uses these signals to determine equalizer mode, and equalizer mode is via mode signal 231 controls.Equalizer 220 can be as known in the art blind pattern (blind mode) (using CMA or RCA algorithm) or operate towards determinating mode (decision-directed mode) (LMS algorithm).

In addition, according to the principle of the invention, equalizer mode element 230 (being also referred to as lock detector at this) provides locking signal 233.Whether on behalf of equalizer 220, the latter restrain.For simply, describe below and be limited to a peacekeeping bidimensional symbol constellations.But the present invention's design is not limited only to this and can easily expands to multi-dimensional constellation.

Forward Fig. 5 now to, Fig. 5 shows the illustrative flow according to the principle of the invention.For example, the flowchart text ground of Fig. 5 is carried out by equalizer mode element 230.About this point, also should be with reference to figure 7, Fig. 7 has illustrated the operation about the present invention's design of one dimension M-VSB symbol constellations known in the art, wherein M=8.Particularly, Fig. 7 shows the diagram of equalizer output signal 221 under low SNR environment.As can be observed from Fig. 7, two perimeters with constellation be defined as with dashed lines arrow 356 and 357 indications.Particularly, indicate the border of one or more perimeters of constellation space with the value of out_threshold.For the 8-VSB symbol constellations, there is the negative out_threshold of for example value (7.0) that for example is worth 7.0 positive out_threshold and with dashed lines 357 expressions of with dashed lines 356 expression.Like this, the amplitude of out_threshold is 7.0.Although should be noted that the present invention design is to illustrate under the symmetry value background, the present invention's design is not only for therewith.As mentioned above, the beginning of one or more perimeters of the value representation constellation space of out_threshold.The perimeter of 8-VSB constellation space shown in Figure 7 is the direction indication of with dashed lines arrow 372 and 373.Like this, think that the received signal points that has more than or equal to the amplitude of out_threshold is outside received signal points, that is:

|Eq_out _n|≥out_thresh (4)

Wherein, Eq_out _nBe illustrated in the received signal points that time n is provided by equalizer output signal 221.

Return Fig. 5, in step 305, equalizer mode element 230 is that N outside received signal points calculating noise power is estimated P _wAs mentioned above, under Fig. 7 background, the perimeter of with dashed lines arrow 372 and 373 direction indication 8-VSB constellation space.For one dimension 8-VSB constellation, describe noise power with following formula and estimate:

e _n=Eq_out _n-S_out _nAnd (5)

$P_w=\frac{1}{N}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{\left|e_n\right|}^2---\left(6\right)$

Wherein in formula (5) and (6), only use outside received signal points.The received signal points (signal 221) that should be noted that formula (5) expression as provide by equalizer 220 with as the error signal e between each sliced symbol (signal 226) that provides by food slicer 225 _n

In step 310, equalizer mode element 230 is determined P _wValue whether less than the threshold value.Should be noted that the threshold value can be programmable.If P _wValue be not less than the threshold value, so in step 320, equalizer mode element 230 is determined the value that equalizers are not locked and give the presentation logic " 0 " of locking signal 233 furnishing an explanation property.But, if P _wValue less than the threshold value, so in step 315, equalizer mode element 230 is determined the value that equalizers are locked and give the presentation logic " 1 " of locking signal 233 furnishing an explanation property.For example, if declaration locking, can indicate so equalizer 220 from blind operator scheme entering surface to the decision pattern.

Forward Fig. 6 now to, Fig. 6 shows the more detail flowchart of the step 305 that is used for Fig. 5.Illustrative ground, definition following parameters: out_cnt and y.Variable out_cnt follows the tracks of the number that drops on the received signal points in the constellation space perimeter.The equalizer output signal 221 of value representation Fig. 4 of y (above be also referred to as Eq_out _n).In the step 350 of Fig. 6, out_cnt is reset to null value with counter.In step 355, absolute value abs (y) and the amplitude of out_threshold of y are made comparisons whether be positioned at the perimeter of constellation space so that determine received signal points.If received signal points is not positioned at the perimeter of constellation space, continue execution in step 355 for next received signal points so.If received signal points is positioned at the perimeter of constellation space, in step 360, increases the value of out_cnt so, and in step 365, carry out incremental noise power calculation, for example formula (4) for received signal points.In step 370, value and the limit value of out_cnt (for example, limit=2048) are made comparisons.If the value of out_cnt does not exceed the limit value, carry out so and return step 355 so that assess next received signal points.But, if the value of out_cnt exceeds the limit value, promptly, a treated N outside received signal points (for example, N=2048), in step 375, finish noise power calculation so, for example, carry out formula (5) for N outside received signal points, and carry out the step 310 of proceeding Fig. 5 so that determine that equalizer 220 is locked still not locked.

Further specifying of the present invention's design has been shown among Fig. 8 and 9.These illustrate the symbol constellations for bidimensional M-QAM known in the art (quadrature amplitude modulation), M=16 wherein, and the diagram of equalizer output signal 221 under low SNR environment, promptly

Eq_out _n＝I _n+j*Q _n (7)

Eq_out wherein _nThe r (nT) that describes before corresponding and be the output signal 221 of equalizer 220 at time n.I is same phase constituent, and Q is an orthogonal component.For clear, homophase (I) and quadrature (Q) axle is not shown.Under Fig. 8 and 9 backgrounds, it is possible that several method is arranged.For example, about the flow chart of above-mentioned Fig. 5 and 6, (I) that can the separate counts received signal points and (Q) component.Can observe from Fig. 8 and 9, be the out_thresholds of every dimension (for example, 372-I, 373-I, 372-Q, 373-Q etc.) definition constellation space, and if for example following formula set up so that received signal points is outside received signal points.

| I _n| 〉=I_out_thresh, or | Q _n| 〉=Q_out_thresh (8)

With the same among Fig. 7, in the perimeter of Fig. 8 and 9 constellation space among both along the direction of arrow 372 and 373.Should be noted that the perimeter of constellation space is the zone of rectangle 379 outsides in Fig. 8, and in Fig. 9, the perimeter of constellation space is defined as four corner regions.Received signal points is positioned at corner region if following formula is set up so.

| I _n| 〉=I_out_thresh and | Q _n| 〉=Q_out_thresh (9)

But the present invention design is only for therewith, and also is possible for other shape of perimeter.

Should also be noted that owing to food slicer output symbol S_out in based on the system of VSB is constant (because only using outside code element), so replace P about Fig. 7 _wAlternative formula can be expressed as:

$S_w=\frac{1}{N}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{|E_q\_{\mathrm{out}}_n|}^2---\left(10\right)$

Because the average signal power of outside code element also is a steady state value, so formula (10) also is applicable to the QAM system.Formula (10) is calculated the gross power of the outside received signal points that comprises noise.Suppose that noise keeps steady state value, then when equalizer convergence above calculated value will become littler.According to the principle of the invention, use S _wOr P _wTrend determine equalizer state-lock, restrain, disperse or non-locking.

According to another embodiment of the present invention, estimate by the signal to noise ratio (snr) that uses received signal, determine equalizer lock detection as the function of above-mentioned noise power estimation.Particularly, after having collected N outside received signal points, noise power is estimated P _wDivided by signal power S _w, promptly

$\mathrm{SNR}=10\×{\log }_{10}\frac{P_w}{S_w}\left(\mathrm{in\; dB}\right)---\left(11\right)$

Wherein, with signal power S _wBe defined as:

$S_w=\frac{1}{M}\underset{i=1}{\overset{M}{\mathrm{\Σ}}}{\left|\mathrm{si}\right|}^2$

S wherein _iBe i code element, and M is the number of symbols in the constellation space, for example for the M=16 of 16-QAM system, for the M=64 of 64-QAM system with for the M=8 of 8-VSB system.Under the background of above-mentioned use corner region, if N enough big (for example, the outside received signal points of N=8192), the SNR that calculates from formula (11) is used for good estimation on the statistics of definite equalizer lock so.Flow process in Figure 10 and 11 there is shown this variation, except comprising step 305 ' and 310 ' (among Figure 10) and step 375 (among Figure 11), Figure 10 and 11 is similar to Fig. 5 and 6.Particularly, 305 steps of image pattern 5 are the same, illustrate in greater detail the step 305 of Figure 10 in Figure 11 '.Except comprising step 375, Figure 11 is similar to Fig. 6, and step 375 is determined SNR according to following formula (11) and (12).Forward Figure 10 to, if except SNR then determining that equalizer is locked, step 310 greater than the thresholdSNR value ' be similar to the step 310 of Fig. 5.

Figure 12 shows another illustrative embodiment of the present invention's design.In this illustrative embodiment, the integrated circuit (IC) 605 that is used for the receiver (not shown) comprises lock detector 620 and at least one register 610 that is coupled to bus 651.Illustrative ground, IC 605 is integrated analog/digital television decoder.But, only show those parts of conceiving relevant IC 605 with the present invention.For example, for simple not shown analog to digital converter, filter, decoder etc.Bus 651 provides and as by the two-way communication between other parts of receiver of processor 650 expression.One or more registers of register 610 expression IC 605, wherein each register comprises one or more as what represent with position 609.The register of IC 605 or its part can read-only, write or reads/write.According to the principle of the invention, lock detector 620 comprises above-mentioned equalizer lock detector feature or operator scheme, and at least one position of register 610 (for example, position 609) is programmable bit, and this programmable bit can be provided with so that start or stop this operator scheme by for example processor 650.Under Figure 12 background, IC 605 receives IF signal 601 to be processed via input pin or the lead of IC 605.The derivation form of this signal is applied to lock detector 620 is used for aforesaid equalizer lock detection.Lock detector 620 provides signal 621, and whether signal 621 indication equalizers (not shown among Figure 12) are locked.Although do not illustrate among Figure 12, signal 621 can be provided to IC 605 circuit external, and/or can be via register 610 accesses.Lock detector 620 is coupled to register 610 via internal bus 611, internal bus 611 expressions other signal path and/or the parts (for example, being used to read the value of the integrator sum counter of describing before) that are used for lock detector 620 interfaces are connected to the IC 605 of register 610 as known in the art.IC 605 provides one or more restoring signals of representing as with signal 606, for example composite video signal.Should be noted that according to the principle of the invention other distortion of IC 605 also is possible, for example, for example do not need external control, and IC 605 may always simply carry out above-mentioned processing so that detect equalizer lock this operator scheme via position 610.

As mentioned above, according to the principle of the invention, receiver determines that noise power estimates to be confirmed as the function of the distribution of received signal points in the constellation space as the equalizer lock of the function of noise power estimation, the different weights value is provided wherein for the zones of different of constellation space.Although should be noted that the present invention's design is not limited in this according to weighted value zero (that is, no weighting) being provided for the received signal points that drops on interior zone and providing weighted value one to describe the present invention's design for the received signal points that drops on the perimeter.Equally, although describe the present invention's design under the background of externally regional and interior zone, the present invention's design is not limited in this.

In view of top situation, foregoing has only illustrated the principle of the invention, therefore should understand that those skilled in the art can design various alternative arrangement, not specialize within the principle of the invention and the spirit and scope at it although clearly describe this alternative arrangement at this.For example, although under context of separate functional elements, illustrate, can go up at one or more integrated circuits (IC) and specialize these function element.Equally, although be shown as discrete component, any or all element can be realized in stored program processor controls (for example, digital signal processor), the stored program processor controls is carried out related software, for example corresponding to the one or more steps shown in for example Fig. 5 and/or 6 etc.In addition, although be shown as the unit that is installed in the television set 10, wherein element also can be distributed in the different units with any compound mode.For example, the receiver 15 of Fig. 3 can be an equipment, as the box of the set-top box of separating with equipment physically, or the part of the box of combined display 20 etc.In addition, although should be noted that it is to describe under the background of terrestrial broadcasting, the principle of the invention can be applicable to the communication system of other type, for example, and satellite, cable etc.Therefore, should understand, can do various modification to illustrative embodiment, and can design other layout, and not depart from the spirit and scope of the present invention that limit as appended claims.

Claims

(according to the modification of the 19th of treaty)

1. method that is used to comprise the receiver of equalizer comprises:

Be provided for receiving the input of the received signal point sequence in the constellation space; And

Determine to estimate, the different weights value is provided wherein for the zones of different of constellation space as the noise power of the function of the distribution of received signal points;

Determine equalizer lock as the function of noise power estimation.

2. method according to claim 1 wherein makes the perimeter weighting of constellation space overweight interior zone.

3. method according to claim 1, determine that wherein the noise power estimating step comprises step:

No weighting is provided for those received signal points in the one or more interior zones that drop on constellation space.

4. method according to claim 3, determine that wherein the equalizer lock step comprises step:

If the noise power of determining is estimated less than threshold value, determine that so equalizer lock occurs.

5. method according to claim 3, wherein at least one perimeter is the corner region of constellation space.

6. method according to claim 1, determine that wherein the equalizer lock step comprises step:

Estimate to determine the signal to noise ratio (snr) estimation according to noise power;

If SNR estimates greater than threshold value, determine that so equalizer is locked.

7. method according to claim 1, wherein constellation space is M-VSB (residual sideband) symbol constellations.

8. method according to claim 1, wherein constellation space is M-QAM (quadrature amplitude modulation) symbol constellations.

9. method according to claim 1, wherein at least one zone is the corner region of constellation space.

10. receiver comprises:

Equalizer is used to provide the received signal point sequence; And

Lock detector;

Wherein lock detector determines that noise power estimates to be confirmed as the function of the distribution of received signal points in the constellation space as the equalizer lock of the function of noise power estimation, the different weights value is provided wherein for the zones of different of constellation space.

11. receiver according to claim 10 wherein makes the perimeter weighting of constellation space overweight interior zone.

12. receiver according to claim 10, wherein lock detector provides no weighting for those received signal points in the one or more interior zones that drop on constellation space.

13. receiver according to claim 12, wherein lock detector is determined the value that noise power is estimated, and if the value of determining less than threshold value, determine that so equalizer lock occurs.

14. receiver according to claim 12, wherein at least one zone is the corner region of constellation space.

15. receiver according to claim 10, wherein lock detector estimate to determine that according to noise power signal to noise ratio (snr) estimates, and if SNR estimate greater than threshold value, determine that so equalizer is locked.

16. receiver according to claim 10, wherein constellation space is M-VSB (residual sideband) symbol constellations.

17. receiver according to claim 10, wherein constellation space is M-QAM (quadrature amplitude modulation) symbol constellations.

18. receiver according to claim 10, wherein at least one zone is the corner region of constellation space.

19. a receiver comprises:

Decoder is used to handle received signal, and wherein decoder is determined the equalizer lock as the function of the signaling point of deriving from received signal; And

Processor, be used to control decoder, make decoder determine that noise power estimates to be confirmed as the function of the distribution of received signal points in the constellation space as the equalizer lock of the function of noise power estimation, the different weights value is provided wherein for the zones of different of constellation space.

20. receiver according to claim 19 wherein makes the perimeter weighting of constellation space overweight interior zone.

21. receiver according to claim 19, wherein decoder provides no weighting for those received signal points in the one or more interior zones that drop on constellation space.

22. receiver according to claim 21, wherein lock detector is determined the value that noise power is estimated, and if the value of determining less than threshold value, determine that so equalizer lock occurs.

23. receiver according to claim 21, wherein at least one zone is the corner region of constellation space.

24. receiver according to claim 19, wherein decoder estimate to determine that according to noise power signal to noise ratio (snr) estimates, and if SNR estimate greater than threshold value, determine that so equalizer is locked.

25. receiver according to claim 19, wherein constellation space is M-VSB (residual sideband) symbol constellations.

26. receiver according to claim 19, wherein constellation space is M-QAM (quadrature amplitude modulation) symbol constellations.

27. receiver according to claim 19, wherein at least one zone is the corner region of constellation space.

Claims (45)

1. method that is used for receiver comprises:

The received signal point sequence is provided; And

Determine that noise power estimates to be confirmed as the function of the distribution of received signal points in the constellation space as the equalizer lock of the function of noise power estimation, the different weights value is provided wherein for the zones of different of constellation space.

2. method according to claim 1 wherein makes the perimeter weighting of constellation space overweight interior zone.

3. method according to claim 1, wherein determining step comprises step:

No weighting is provided for those received signal points in the one or more interior zones that drop on constellation space.

4. method according to claim 3, wherein claim 3 described certain step comprises step:

Determine the value that noise power is estimated; And

If the value of determining, determines so that equalizer lock occurs less than threshold value.

5. method according to claim 3, wherein at least one perimeter is the corner region of constellation space.

6. method according to claim 1, wherein determining step comprises step:

Estimate to determine the signal to noise ratio (snr) estimation according to noise power;

If SNR estimates greater than threshold value, determine that so equalizer is locked.

7. method according to claim 1, wherein constellation space is M-VSB (residual sideband) symbol constellations.

8. method according to claim 1, wherein constellation space is M-QAM (quadrature amplitude modulation) symbol constellations.

9. method according to claim 1, wherein at least one zone is the corner region of constellation space.

10 1 kinds of receivers comprise:

Be used to provide the device of received signal point sequence; And

Be used for determining the device of the equalizer lock of the function estimated as noise power, noise power estimates to be confirmed as the function of the distribution of received signal points in the constellation space, the different weights value is provided wherein for the zones of different of constellation space.

11. receiver according to claim 10 wherein makes the perimeter weighting of constellation space overweight interior zone.

12. receiver according to claim 10, the device that wherein is used to determine provides no weighting for those received signal points in the one or more interior zones that drop on constellation space.

13. receiver according to claim 12 is used for wherein determining that the device of equalizer lock determines the value that noise power is estimated, and if the value of determining less than threshold value, determine that so equalizer lock occurs.

14. receiver according to claim 12, wherein at least one zone is the corner region of constellation space.

15. receiver according to claim 10, the device that wherein is used for determining equalizer lock estimates to determine that according to noise power signal to noise ratio (snr) estimates, and if SNR estimate greater than threshold value, determine that so equalizer is locked.

16. receiver according to claim 10, wherein constellation space is M-VSB (residual sideband) symbol constellations.

17. receiver according to claim 10, wherein constellation space is M-QAM (quadrature amplitude modulation) symbol constellations.

18. receiver according to claim 10, wherein at least one zone is the corner region of constellation space.

19. a receiver comprises:

Equalizer is used to provide the received signal point sequence; And

Lock detector;

Wherein lock detector determines that noise power estimates to be confirmed as the function of the distribution of received signal points in the constellation space as the equalizer lock of the function of noise power estimation, the different weights value is provided wherein for the zones of different of constellation space.

20. receiver according to claim 19 wherein makes the perimeter weighting of constellation space overweight interior zone.

21. receiver according to claim 19, wherein lock detector provides no weighting for those received signal points in the one or more interior zones that drop on constellation space.

22. receiver according to claim 21, wherein lock detector is determined the value that noise power is estimated, and if the value of determining less than threshold value, determine that so equalizer lock occurs.

23. receiver according to claim 21, wherein at least one zone is the corner region of constellation space.

24. receiver according to claim 19, wherein lock detector estimate to determine that according to noise power signal to noise ratio (snr) estimates, and if SNR estimate greater than threshold value, determine that so equalizer is locked.

25. receiver according to claim 19, wherein constellation space is M-VSB (residual sideband) symbol constellations.

26. receiver according to claim 19, wherein constellation space is M-QAM (quadrature amplitude modulation) symbol constellations.

27. receiver according to claim 19, wherein at least one zone is the corner region of constellation space.

28. a receiver comprises:

Decoder is used to handle received signal; And

At least one register, be used to be provided with the operator scheme of decoder, wherein at least a operator scheme of decoder is determined the equalizer lock as the function of noise power estimation, noise power estimates to be confirmed as the function of the distribution of received signal points in the constellation space, the different weights value is provided wherein for the zones of different of constellation space.

29. receiver according to claim 28 wherein makes the perimeter weighting of constellation space overweight interior zone.

30. receiver according to claim 28, wherein decoder provides no weighting for those received signal points in the one or more interior zones that drop on constellation space.

31. receiver according to claim 30, wherein decoder is determined the value that noise power is estimated, and if the value of determining less than threshold value, determine that so equalizer lock occurs.

32. receiver according to claim 30, wherein at least one zone is the corner region of constellation space.

33. receiver according to claim 28, wherein decoder estimate to determine that according to noise power signal to noise ratio (snr) estimates, and if SNR estimate greater than threshold value, determine that so equalizer is locked.

34. receiver according to claim 28, wherein constellation space is M-VSB (residual sideband) symbol constellations.

35. receiver according to claim 28, wherein constellation space is M-QAM (quadrature amplitude modulation) symbol constellations.

36. receiver according to claim 28, wherein at least one zone is the corner region of constellation space.

37. a receiver comprises:

Decoder is used to handle received signal, and wherein decoder is determined the equalizer lock as the function of the signaling point of deriving from received signal; And

Processor, be used to control decoder, make decoder determine that noise power estimates to be confirmed as the function of the distribution of received signal points in the constellation space as the equalizer lock of the function of noise power estimation, the different weights value is provided wherein for the zones of different of constellation space.

38., wherein make the perimeter weighting of constellation space overweight interior zone according to the described receiver of claim 37.

39. according to the described receiver of claim 37, wherein decoder provides no weighting for those received signal points in the one or more interior zones that drop on constellation space.

40. according to the described receiver of claim 39, wherein lock detector is determined the value that noise power is estimated, and if the value of determining less than threshold value, determine that so equalizer lock occurs.

41. according to the described receiver of claim 39, wherein at least one zone is the corner region of constellation space.

42. according to the described receiver of claim 37, wherein decoder estimate to determine that according to noise power signal to noise ratio (snr) estimates, and if SNR estimate greater than threshold value, determine that so equalizer is locked.

43. according to the described receiver of claim 37, wherein constellation space is M-VSB (residual sideband) symbol constellations.

44. according to the described receiver of claim 37, wherein constellation space is M-QAM (quadrature amplitude modulation) symbol constellations.

45. according to the described receiver of claim 37, wherein at least one zone is the corner region of constellation space.

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