CN101232366B - Mobile communication device and method for reducing fake burst checking used therebetween - Google Patents

Abstract

The invention discloses a mobile communication device (10) and a method for reducing fake burst test therein. The communication device (10) comprises a carrier recovering module (118) for burst test according to sampled input data (I/Q); the carrier recovering module (118) comprises an angel calculator (14)) for calculating a phase value of the input data (I/Q) and a burst detector (130) for burst test with the phase value; the burst detector (130) comprises an energy calculating module (505) for calculating en energy estimated value of the input data (I/Q), a secondary difference value setting module (506) for outputting a value for replacing the secondary difference value to a mobile average module (503) for calculating a mobile average value for input, etc.; a test output module (504) outputs a burst test signal when the mobile average value is less than a burst threshold.

Description

Mobile communication equipment and the method that detects for the false burst of minimizing wherein

Technical field

The present invention relates to mobile communication system, more particularly, relate to the PHS telephone plant and reach the burst detection method that is used for wherein.

Background technology

Wireless communication system allows the user transmitting and receive data between the user and/or between user and base station.Generally speaking, wireless communication system attempts in the situation that the satisfied demand of sharing other users of this system maximizes each user's transfer of data.Time division multiple access (TDMA) is exactly a kind of being used in the situation that make minimum interference between the user of wireless communication system make the example of utilizing maximized method to the bandwidth of distributing.Many dissimilar wireless communication systems have all adopted TDMA, for example personal handyphone system (PHS).

Fig. 1 shows the exemplary functional block diagram according to the PHS phone 10 of prior art.The PHS telephone system comprises the PHS phone 10 with antenna 12 and the base station 11 with antenna 13.Exemplary PHS phone 10 comprises signal processing module 16, memory 22, power supply 24 and I/O module 26.Signal processing module 16 comprises transmitter module 18 and receiver module 20.Transmitter module 18 converts user's input to the PHS compatible signal.Receiver module 20 will become from the data transaction that antenna 12 receives the discernible form of user and output.Signal processing module 16 utilizes memory 22 to sending to the data of antenna 12 and from antenna, 12 data that receive being processed.

In digital communication system, data are generally by the baseband signal of utilizing beared information, carrier signal to be modulated to launch.Quadrature Phase Shift Keying modulation (QPSK) is a kind of phase-modulation that usually uses in communication system.In QPSK, represent dibit value 00,01,10 and 11 with four symbols.QPSK is with this four sign map to four fixing phase angle.Another kind of example PI/4-DQPSK is utilized the differential coding scheme, and the mapping in this scheme between symbol and phase angle changes.In addition, PI/4-DQPSK is mapped to a reality parallactic angle and an empty phase angle with each in above-mentioned four symbols, thereby produces the constellation of eight points.In the PHS phone, adopted simple transmitting/receiving technology, for example, PI/4-DQPSK modulation and Non-coherent Demodulation.

When utilizing non-coherent demodulation, it is very important that carrier wave recovers.A kind of carrier frequency recovery scheme is that automatic frequency is controlled (AFC).But in current PHS system, data are sent out with burst mode.Therefore, it is relatively short that AFC becomes stable response time, usually at several symbols to the dozens of symbol.Therefore, in PHS, adopted open-loop carrier frequency estimation, happened suddenly to realize that by detection carrier wave recovers.

In PHS, the targeting sequencing in control slot (PR) has suitable characteristic can be used for detecting this burst (perhaps time slot).Referring to Fig. 2, Fig. 2 shows in the PHS system, control slot (control channel, form CCH).In the PHS system, the PR symbol is to repeat by " 1001 " pattern that forms for 16 times, utilizes this periodic characteristic of targeting sequencing PR, can fast detecting go out to happen suddenly.

But, in the PHS phone, due to signal remaining in hardware, cause the probability of error detection quite high.

Summary of the invention

In order to solve foregoing problems, one aspect of the present invention discloses a kind of mobile communication equipment 10.This equipment comprises according to detect the carrier recovery block 118 of burst through the input data (I/Q) of sampling.Carrier recovery block 118 comprises for the angle computer 140 of the phase value that calculates input data (I/Q) and utilizes described phase value to detect the burst detector 130 of burst.

Burst detector 130 comprises that difference block 501, secondary difference block 502, rolling average module 503, detection output module 504, energy computing module 505 and a secondary difference arrange module 506.One time difference block 501 calculates difference one time for the difference of calculating two phase values.Secondary difference block 502 is used for the difference of two differences of calculating and calculates the secondary difference, and it is outputed to rolling average module 503.Energy computing module 505 is used for calculating the energy estimated value of described input data (I/Q).The secondary difference arranges module 506 and is used in described energy estimated value specific energy threshold value hour, and the replacement of output secondary difference is worth rolling average module 503.Rolling average module 503 is used for input moving average calculation on average window of module 506 is set from secondary difference block 502 and secondary difference.Detect output module 504 in described moving average than burst threshold hour output burst detection signal.

Another aspect of the present invention discloses a kind of for detect the method for burst at mobile communication equipment.The method comprises the following steps: the secondary difference of calculating the phase value of the input data (I/Q) through sampling; Calculate the energy estimated value of described input data (I/Q) through sampling; And detect described burst according to described secondary difference and energy estimated value.

Technical scheme according to the present invention detects burst by the detection to signal energy mistakenly thereby greatly reduced.

Description of drawings

Fig. 1 shows the schematic block diagram of PHS system;

Fig. 2 shows the form of control slot (CCH) in the PHS system;

Fig. 3 shows the partial function block diagram in PHS phone RX path;

Fig. 4 shows in detail the functional block diagram of the carrier recovery block 118 in Fig. 3;

Fig. 5 A and Fig. 5 B illustrate in greater detail the functional block diagram of two kinds of implementations of the burst detector 130 in Fig. 4;

Fig. 6 A and 6B show respectively the simulate signal waveform of difference and secondary difference;

Fig. 7 shows the burst detection signal waveform of emulation;

Fig. 8 A and 8B show the flow chart of two kinds of implementations of the method for detection of happening suddenly of the present invention; And

Fig. 9 A and 9B illustrate in greater detail respectively the implementation of Fig. 8 A and Fig. 8 B.

Embodiment

A lot of details have been set forth in detailed description to the specific embodiment of the present invention below, so that fully understand the present invention.But, do not have these details can implement the present invention yet, be clearly for a person skilled in the art.With reference to the PHS phone, the specific embodiment of the present invention is described below, but the present invention is not limited to the PHS phone.

With reference now to Fig. 3, present invention is described, the figure shows the block diagram of a part in the receive data path of PHS phone.AFE (analog front end) (AFE) part 110 comprises analog to digital converter 112, is used for inputting data and becomes digital signal from analog signal conversion.Digital signal after conversion is transferred to hardware accelerator 114.The signal after the carrier frequency shift compensation is processed and generated to 114 pairs of digital input datas of hardware accelerator.

Hardware accelerator 114 comprises decimation filter 116, and (N * fb) form through accelerating the input data, wherein N is the integer greater than 0 to decimation filter 116 with N times of character rate.Input data through accelerating are transferred to carrier recovery block 118 and circulator module 120 from decimation filter 116.The output of circulator module 120 is transferred to A/B buffer register 122.Carrier recovery block 118 detects burst, and estimates the carrier frequency shift between the signal of the signal that receives and emission, and the below will be explained in more detail it.

Circulator module 120 is used for carrier frequency is compensated to form the rear signal of rotation.After being stored in the rotation in A/B buffer register 122, signal is transferred to digital signal processor module (DSP) 124.DSP 124 comprises equalizer module 126.Correlator block 128, limiter 130 and slow tracker 132.

Carrier recovery block 118 has two basic functions: one is to detect time division duplex (TDD) burst, another be estimating received signal and transmit between carrier frequency shift.This carrier frequency shift that estimates is used to drive the skew of circulator module 120 in to received signal and compensates or be used for driving AFC the frequency of local carrier generator is proofreaied and correct.

With reference now to Fig. 4, describe carrier recovery block 118 in detail.Carrier recovery block 118 comprises angle computer 140, burst detector 130, carrier offset calculator (COC) 132, delay buffer 134 and average detector 214.

Burst detection sign (burstdetect) triggering from burst detector 130 is derived the carrier shift frequency from the signal of delay buffer 134 by COC 132.Resulting skew is transformed into the anglec of rotation, then is delivered to the circulator module 120 in Fig. 1, makes the frequency shift (FS) that receives in signal to be compensated.

Angle computer 140 is based on homophase (I) and quadrature (Q) component of input data, by the calculating of arctan angle, will input data (I/Q) for each sampling and be transformed into pure phase position information.That is, for in-phase component I and the quadrature component Q of input data, phase angle θ=arctan (Q/I).Table 1 shows the example that size is 12 * 16 arctan table, and wherein π is represented as 0 * 10000.

Table 1 CORDIC Arctangent table

Arctan shows (Q.16)	The position scope	Value (without symbol)	Represented value
				[0]	[15∶0]	16384	Atan(1)＝1/4*π
[1]	[15∶0]	9672	Atan(1/2)

[2]	[15∶0]	5110	Atan(1/4)
				[3]	[15∶0]	2594	Atan(1/8)
[4]	[15∶0]	502	Atan(1/16)
				[5]	[15∶0]	652	Atan(1/32)
[6]	[15∶0]	326	Atan(1/64)
				[7]	[15∶0]	163	Atan(1/128)
[8]	[15∶0]	81	Atan(1/256)
				[9]	[15∶0]	41	Atan(1/512)
[10]	[15∶0]	20	Atan(1/1024)
				[11]	[15∶0]	10	Atan(1/2048)

The phase value that angle computer 140 calculates is output to burst detector 130.

Be the situation of different value for the N in decimation filter 116, burst detector 130 can have the similar path configurations of N bar.But for simplicity, the below is described in detail the burst detector 130 of one embodiment of the invention for N=1.In this case, each symbol is corresponding to a sampling, thereby adjacent two phase values are corresponding to the phase information of adjacent two symbols.

Burst detector 130 mainly comprises two paths, article one, be used for the pure phase position information that is received from angle computer 140 is processed, another is used for the energy of the input data (I/Q) that are received from decimation filter 116 is processed, thereby prevents error detection to burst in conjunction with these two kinds of processing.These two kinds of processing can executed in parallel, also can serial carry out.

Block diagram according to one embodiment of the invention burst detector 130 under the executed in parallel configuration has been shown in Fig. 5 A.Burst detector 130 comprises that difference block 501, secondary difference block 502, rolling average module 503, detection output module 504, energy computing module 505 and a secondary difference arrange module 506.

501 pairs of continuous two phase value calculated difference from angle computer 140 inputs of a difference block, that is, and θ (k)-θ (k-1).Then, 502 pairs of two input execution difference computings continuously from a difference block 501 of secondary difference block namely, are carried out twice difference to all original phase values.Then the secondary difference that calculates is output to rolling average module 503.

505 pairs of energy computing modules add up (back will be explained this accumulation principle and algorithm in more detail) at average window from the energy of the input data (I/Q) of decimation filter 116 inputs, and the energy estimated value that obtains of then adding up outputs to the secondary difference module 506 is set.

The secondary difference arranges module 506 in the energy estimated value during less than predefined energy threshold ThN, with one enough large value MAX output to rolling average module 503 as the secondary difference.

Rolling average module 503 substitutes the former with the latter not only having received from the secondary difference of secondary difference block 502 for same sampling but also having received when from the secondary difference, the secondary difference of module 506 being set when calculating.Then, rolling average module 503 is to its input moving average calculation on average window.That is, with two adjacent input additions and calculating and absolute value, then on width is the average window of M, a nearest M absolute value is added up moving average calculation.Detecting output module 504 will compare with the burst threshold ThB that is scheduled to from each moving average of rolling average module 503, if a moving average is less than ThB, just generates the burst detection signal and it is outputed to COC 132 (Fig. 4).

The burst detector of an alternative embodiment of the invention and aforementioned similar is just fastened the employing serial mode in the pass of energy measuring and pure phase position detection, as shown in Fig. 5 B.Fig. 5 B shows the block diagram of carrying out burst detector 130 under configuration in serial.For the input data (I/Q) for each symbol, energy computing module 505 first carries out the energy estimated value and calculates, then arrange in module 506 in the secondary difference, if this energy estimated value outputs to rolling average module 503 with the MAX value as the secondary difference less than predetermined power threshold value ThN.Otherwise the secondary difference arranges module 506 and sends enable signals to difference block 501, makes it can calculate a difference and it is outputed to secondary difference block 502 and calculate the secondary difference.

In PHS equipment, burst detector 130 has utilized the targeting sequencing (PR) in the PHS control slot to detect the TDD burst.The below describes the theoretical foundation of this detection in detail.

Inband signaling for reception:

s _r(t)＝A(t)cos(Δω _ct+θ′(t)+φ)+n(t)，

Wherein, $A\left(t\right)=\underset{k}{\mathrm{\Σ}}g(t-\mathrm{kT}),$ G (t) is the cosine impulse that rises, Δ ω _cBe carrier shift, θ ' is (t) the receiver phase modulation, and φ is the fixed phase offsets between transmitter and receiver, and n (t) is Gaussian noise.If ignore poor between transmitter phase modulation and receiver phase modulation, S _r(t) phase signal is only phz (t)=2 π Δ ft+ θ (t)+φ.

After a difference, phase difference variable is:

phzDiff1(t)＝phz(t)-phz(t-T)＝2πΔfT+θ(t)-θ(t-T)。Very clear, the signal after this difference is the one-period signal, and its center is 1/4 π+2 π Δ fT, and the cycle is 2T, and phase value exists

In, as shown in Figure 6A.

After twice difference, phase difference variable is:

phzDiff2(t)＝phzDiff1(t)-phzDiff1(t-T)＝θ(t)+θ(t-2T)-2θ(t-T)。Signal after this twice difference is centered by 0, and the cycle is the periodic signal of 2T.The value of this signal is in [π, π], as shown in Fig. 6 B.

The burst detection algorithm is the rolling average of calculating the secondary difference on the average window of M at a width.That is, with adjacent two secondary differences addition and calculate absolute value, then on this average window, a nearest M absolute value is added up.Then, this algorithm each moving average that will calculate and a default burst threshold ThB compare to have judged whether that burst is detected.Order

$\mathrm{sumPhase}=\underset{m=0}{\overset{M-1}{\mathrm{\Σ}}}\mathrm{abs}(\mathrm{phzDiff}2(t-\mathrm{mT})+\mathrm{phzDiff}2(t-\mathrm{mT}-T)),$

Wherein the M length of window, select M=16 in situation of the present invention.Above-mentioned equation can be reduced to

$\mathrm{sumPhase}=\underset{m=0}{\overset{M-1}{\mathrm{\Σ}}}\mathrm{abs}(\mathrm{\θ}(t-\mathrm{mT})-\mathrm{\θ}(t-\mathrm{mT}-T)-\mathrm{\θ}(t-\mathrm{mT}-2T)+\mathrm{\θ}(t-\mathrm{mT}-3T))$

$=\underset{m=0}{\overset{M-1}{\mathrm{\Σ}}}\mathrm{abs}(\mathrm{phzDiff}1(t-\mathrm{mT})-\mathrm{phzDiff}1(t-\mathrm{mT}-2T))$

In Fig. 7, show the sumPhase signal.This figure is to be 3f for sampling rate _bExample shown in, f _bIs-symbol speed.Very clear, during PR, sumPhase is much smaller than other signal periods, so this is the good indicator that burst detects.

If sumPhase is less than burst threshold ThB, burst is detected.The value of ThB in situation of the present invention, is selected ThB=3* π from repeatedly deriving simulation.

But owing to there being residual sin waveform in hardware circuit, and this sin waveform is very difficult to thorough elimination, so only adopt above-mentioned pure phase position information to detect burst, the probability of error detection is very high.Find in test, compare with real signal, the amplitude of above-mentioned residual sin ripple is very little, so can be according to formula on suitable window $\underset{j=0}{\overset{w-1}{\mathrm{\Σ}}}\left|I(k-j)\right|+\left|Q(k-j)\right|$ Energy to the input data adds up the estimated signal energy, and gets rid of error detection according to AD dynamic range or suitable threshold value, and wherein k is the sampling of current sign, and w is the width of energy accumulation window.

The above has described and has realized exemplary means of the present invention.Another aspect of the present invention relates to the method for the burst detection of mobile communication equipment.The method mainly comprises the secondary difference of the phase value of each sampling of calculating input data (I/Q), and estimate input data (I/Q) the energy estimated value, then according to detecting burst about the secondary difference of phase information with about the energy estimated value of energy information, thereby reduce the error detection probability.

Fig. 8 A shows parallel detecting method according to an embodiment of the invention.In step S801, calculate the phase value of all input data (I/Q).In this step, through sampled signal i (k), utilize its in-phase component I (k) and quadrature component Q (k) to calculate its phase angle θ (k)=arctan (Q (k)/I (k)) for each.Then in step S802, according to d θ (k)=θ (k)-θ (k-1), the phase information of adjacent two signals is calculated a difference.Then in step S803, according to d ²θ (k)=d θ (k)-d θ (k-1) carries out difference to adjacent two differences and obtains the secondary difference.With abovementioned steps concurrently, in step S804 for the sampling according to $\underset{j=0}{\overset{w-1}{\mathrm{\Σ}}}\left|I(k-j)\right|+\left|Q(k-j)\right|$ Calculate the energy estimated value sumN of nearest j input data (I/Q).Then, in step S805, judge that whether sumN is less than predetermined energy threshold ThN.If sumN is less than energy threshold ThN, in step S806, the secondary difference is set to enough large value MAX, and then process advances to step S807.In this case, this secondary difference that is set as MAX will be used in the calculating of step S807.

If in step S805, judgment result is that sumN more than or equal to threshold value ThN, process directly advances to step S807, and at this moment, the secondary difference that calculates in step S803 will be for the calculating of step S807.

In step S807, be that on the window of M, the secondary difference to input is carried out rolling average at width.In step S808, according to the result of the rolling average in step S807, judge whether to detect burst.If this result is less than predetermined burst threshold ThB, the output indication detects the signal of burst, otherwise does not export the signal that indication detects burst.

Fig. 8 B shows serial detection method according to an embodiment of the invention.At first, in step S901 for each the sampling according to $\underset{j=0}{\overset{w-1}{\mathrm{\Σ}}}\left|I(k-j)\right|+\left|Q(k-j)\right|$ Calculate the energy estimated value sumN of nearest j input data (I/Q).Then, in step S902, judge that whether sumN is less than energy threshold ThN.If judge sumN less than ThN in step S902, in step S903 with one enough large value MAX as the secondary difference.This secondary difference that is set to MAX will be used in step S907.

If judge sumN more than or equal to ThN in step S902, in step S904, calculate the phase value of all input data (I/Q).In this step, through sampled signal i (k), utilize its in-phase component I (k) and quadrature component Q (k) to calculate its phase angle θ (k)=arctan (Q (k)/I (k)) for each.Then in step S905, according to d θ (k)=θ (k)-θ (k-1), the phase information of adjacent two signals is calculated a difference.Then in step S906, according to d ²θ (k)=d θ (k)-d θ (k-1) carries out difference to adjacent two differences and obtains the secondary difference.This secondary difference will be used in the calculating of step S907.

Next, in step S907, be to carry out rolling average on the moving window of M at width to the secondary difference of input.In step S908, according to the result of the rolling average in step S907, the signal of burst detected if this result less than predetermined burst threshold ThB, is exported indication, otherwise do not export the signal that indication detects burst.

With reference now to Fig. 9 A, a kind of exemplary realization of the parallel detecting method in Fig. 8 A is described in more detail.Method starts from step S1001, and the k that is used for to counting through the input data of sampling is set to 0.Then in step S1002, when receiving a sampling of input data (I/Q), k is added 1.Then in step S1003, input data i (k) for what receive through sampling, utilize its in-phase component I (k) and quadrature component Q (k) to calculate its phase angle θ (k)=arctan (Q (k)/I (k)).Then whether judge k greater than 1 in determining step S1004, if otherwise return to step S1002, carry out a difference d θ (k)=θ (k)-θ (k-1) otherwise advance to step S1005, then the method advances to step S1006.In step S1006, whether judge k greater than 2, if otherwise turn back to step S1002, otherwise continue to step S1007.In step S1007, the difference result of step S1005 is carried out difference d ²θ (k)=d θ (k)-d θ (k-1).

With above-mentioned steps concurrently, execution in step S1008 after the step 1002, in this step for data input data i (k) calculate its energy n (k)=| I (k) |+| Q (k) |.Then in step S1009, judge that k is whether greater than the width w of energy accumulation window, if k less than w, advances to step S1013, otherwise mean and accumulated the energy that reaches an energy accumulation window width w number data, can add up the estimated signal energy.Then, in step S1010, the calculating energy estimated value $\mathrm{sumN}=\underset{j=0}{\overset{w-1}{\mathrm{\Σ}}}n(k-j).$ Then in step S1011, whether judge sumN less than predetermined energy threshold ThN, if be not less than this threshold value, process advances to step S1013.

In step S1011, if judgment result is that sumN less than this predetermined power threshold value ThN, in step S1012, with one enough large value MAX as the secondary difference of the calculating that is used for step S1014.In this case, the secondary difference that calculates in step S1007 is covered by this MAX.Then process advances to step S1013

Then, in step S1013, for predetermined average window length M, judge k-M-2 〉=0, that is, whether exist abundant secondary difference result to be used for suing for peace on average length of window.If the determination result is NO for step S1013, process turns back to step S1002, and else process advances to step S1014.

In step S1014, the result that will calculate is carried out rolling average on average window length M, that is: in step S1006 $\mathrm{sum}\left(k\right)=\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}\mathrm{abs}({\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="S2007101541654E00021.png,S2007101541654E00111.png"\; state="\{\{state\}\}">d</figure-callout>}}^2\mathrm{\&theta;}(k-m)+{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="S2007101541654E00021.png,S2007101541654E00111.png"\; state="\{\{state\}\}">d</figure-callout>}}^2\mathrm{\&theta;}(k-m-1)).$ Then, in step S1009, judgement sum (k)＜ThB, wherein ThB is the threshold value of presetting.If the determination result is NO for step S1015, process turns back to step S1002, otherwise advances to step S1016.In step S1016, the output indication detects the signal of burst, and then process turns back to step S1002.

With reference now to Fig. 9 B, a kind of exemplary realization of the serial detection method in Fig. 8 B is described in more detail.Identical in the merit that in Fig. 9 B, each step is completed and Fig. 9 A, just execution sequence and condition change to some extent.To the calculating of energy value be no longer executed in parallel to the calculating of phase information, if but with secondary difference d ²θ (k) is set to MAX, for sampled data k, will no longer calculate secondary difference d by phase information ²θ (k) is specifically referring to accompanying drawing.

The preferred embodiments of the present invention have more than been described.Although described in a particular embodiment the present invention, the present invention also can realize with the form of hardware, software, firmware or its combination, and can be applied in system, subsystem and parts thereof or subassembly.When realizing with software, element of the present invention is that code segment is to complete necessary task basically.

Claims (10)

1. a mobile communication equipment (10), comprise according to detect the carrier recovery block (118) of burst through the input data (I/Q) of sampling, described carrier recovery block (118) comprises for the angle computer (140) of the phase value that calculates the input data and utilizes described phase value to detect the burst detector (130) of burst

Wherein, described burst detector (130) comprises that a difference block (501), secondary difference block (502), rolling average module (503), detection output module (504), energy computing module (505) and secondary difference arrange module (506)

A difference block (501), the difference that is used for two phase values of calculating is calculated difference one time;

Secondary difference block (502), the difference that is used for two differences of calculating is calculated the secondary difference, and it is outputed to rolling average module (503);

Energy computing module (505) is for the energy estimated value of calculating described input data;

The secondary difference arranges module (506), is used in described energy estimated value specific energy threshold value hour, and the replacement of output secondary difference is worth rolling average module (503);

Rolling average module (503) is used for the input moving average calculation of module (506) is set from secondary difference block (502) and secondary difference; And

Detect output module (504), be used in described moving average than burst threshold hour output burst detection signal.

2. mobile communication equipment as claimed in claim 1 (10), wherein, described energy computing module (505) carries out accumulation calculating to the energy value of a plurality of samplings and goes out described energy estimated value.

3. mobile communication equipment as claimed in claim 2 (10), wherein, described rolling average module (503) is if arrange from the secondary difference the described secondary difference that module (506) receives described replacement value input from described secondary difference block (502) with described replacement value replacement when calculating.

4. mobile communication equipment as claimed in claim 2 (10), wherein, described secondary difference arranges module (506) also in described energy estimated value during more than or equal to described energy threshold, to a described difference block (501) output enable signal, a described difference block (501) is only just carried out computing when receiving enable signal.

5. be the PHS phone as the described mobile communication equipment of aforementioned any claim (10).

6. one kind is used for detecting at mobile communication equipment (10) method that happens suddenly, and comprises the following steps:

Calculating is through the secondary difference of the phase value of the input data of sampling;

Calculate the energy estimated value of described input data through sampling; And

Detect described burst according to described secondary difference and energy estimated value, the step of wherein calculating the secondary difference comprises the following steps:

Calculate the phase value of described input data for each sampling;

Calculate the difference of corresponding two adjacent phase values and calculate difference one time; And

Calculate the difference of corresponding adjacent two differences and calculate the secondary difference, wherein the step of calculating energy estimated value comprises the following steps:

Calculate the energy value of described input data for each sampling; And

A plurality of described energy values are added up to calculate described energy estimated value,

The step of the described burst of wherein said detection comprises:

Replace described secondary difference with the replacement value in described energy estimated value during less than energy threshold;

Calculate the moving average of secondary difference; And

Detect described burst according to described moving average and burst threshold.

7. method as claimed in claim 6, the step of wherein said calculating secondary difference and the step of calculating energy estimated value are executed in parallel.

8. method as claimed in claim 6, the step of wherein said calculating secondary difference in the situation that described energy estimated value just carry out more than or equal to energy threshold.

9. method as claimed in claim 8, the step of the described burst of wherein said detection comprises:

Calculate the moving average of secondary difference; And

Detect burst according to described moving average and burst threshold.

10. method as described in claim 6 or 9 wherein, detects burst during less than described burst threshold in described moving average, burst do not detected during more than or equal to described burst threshold in described moving average.

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