CN101150828B - Quick paging channel detection with signal to noise ratio dependent thresholds - Google Patents

Abstract

A method and system is disclosed for detecting paging indicators using a multi-stage and multi-threshold detection mechanism so that a mobile terminal can be removed from an idle mode appropriately. After receiving a first paging indicator, it is determined whether a first indicator measurement corresponding to the first paging indicator is between a first and a second predetermined thresholds. After receiving a second paging indicator which may be a temporal diversity counterpart of the first paging indicator, a second indicator measurement derived based on both the first and second paging indicators is compared against a third predetermined threshold, wherein the mobile terminal is removed from the idle mode when both comparisons are appropriately conducted.

Description

Utilize signal to noise ratio dependent thresholds to detect the method and system of quick paging channel

Technical field

The present invention relates generally to wireless communication system, relate in particular to the method and system of the existence of sense switch signaling in cordless communication network.

Background technology

Quick paging channel (QPCH) is the uncoded channel that is used in based on transmitting the switch signaling in the telecommunication system of CDMA (code division multiple access).This channel transmits the various designator as Paging Indicator, broadcast indicator and configuration variation designator.Below discussion will use certain indicators as an example as the Paging Indicator, still, should be understood that anything that can be applied to Paging Indicator also can be applied to other designator of QPCH transmission.

In cordless communication network, when both not having sound also not have data call, portable terminal remains on idle condition to save battery power.Under idle condition, portable terminal every one section time cycle property that is generally millisecond order of magnitude be waken up, monitor whether Paging Indicator exists the paging that portable terminal is made to detect.Simple relatively pre-defined algorithm is generally used for determining whether Paging Indicator indicates existence carrying out or upcoming sound or data call.If the result of pre-defined algorithm is sure, then portable terminal is connected, and may comprise the nearly special use in the 100ms time interval or the information of broadcast with decoding by what common channel transmitted.If according to simple algorithm determine whether at last fixed, then portable terminal turns back to " park mode ", wherein, and during " park mode ", when making a few critical component continue to keep basic regularly requirement, most of mobile terminal components are disconnected to save battery power.As known for one of ordinary skill in the art, portable terminal is frequent more to the information decoding in the common channel, and the electric energy that portable terminal must consume is just many more.Therefore, needing increases the stand-by period, or portable terminal is in the time quantum under " park mode ".

In order to increase the stand-by period, wireless communication system regular and communication of mobile terminal sends same Paging Indicator several times in time, to indicate whether to exist the paging to portable terminal.For example, the 3rd generation collaborative project 2 (3rd Generation Partnership Project 2) have described the quick paging channel that designs for this purpose under the CDMA2000 environment.Related content sees also the " physical layer standard of CDMA2000 spread spectrum system (" Physical Layer Standard for CDMA2000 Spread Spectrum Systems ", 3GPP2C.S0002, March, 2000).Can also be referring to " the upper strata of CDMA2000 spread spectrum system (2000) (layer 3) signaling standard (" Upper Layer (Layer3) Signaling Standard for CDMA2000Spread Spectrum Systems (2000) "; 3GPP2C.S0005; March, 2000).The QPCH designator generally is the ON/OFF keying, to reduce electric energy transmitting.Paging Indicator is used for sending the relevant signal that has beep-page message to portable terminal in the predetermined paging time-slot of QPCH.If Paging Indicator is represented to open, then portable terminal should be waken up and can paging receiving.If Paging Indicator is represented to close, then portable terminal can continue to be in idle condition with saves energy.Repeat to send this designator once with acquisition time decline diversity information.

In order to save battery power, key is to detect the existence of Paging Indicator reliably and effectively.Because the existence of noise and the decline of air communication, it is very low that signal to noise ratio (snr) may become, and this all faces the challenge any testing mechanism.Two kinds of mistakes relevant of general existence with paging.The type i mistake promptly, may cause the spurious alarm mistake of spurious alarm, from and cause that the incorrect paging that more battery powers are consumed detects.The Type II mistake, that is, lost sound/data call incorrect detection lose mistake.In wireless communication system, have to testing mechanism is designed to spurious alarm is dropped to minimum level and the Loss Rate exponentially is increased.

The single-stage testing mechanism is disclosed in prior art references, wherein, for given spurious alarm is provided with a threshold value and makes the detection probability maximization.More contents see also " statistical signal processing basis: etection theory (" Fundamentals of Statistical Signal Processing:Detection Theory ", PrenticeHall PTR, 1 ^StEdtion, March1993) ".But, owing to when channel gain changes than, only use single threshold value, thus detect for multistage Paging Indicator, this mechanism can not be practical that spurious alarm and Loss Rate are dropped to is minimum.Though other existing method has solved more above-mentioned problems, can not multistage effectively detection Paging Indicator.

Existing paging detection method can not utilize known signal to noise ratio (snr) channel to improve the detection performance.In fact, the great majority design normally proposes in order to tackle worst case.If certain design makes the spurious alarm probability all keep constant on whole working range, the loss detection probability will almost be zero on high SNR so.Even the loss detection probability ground that can sacrifice hardly on the high SNR is reduced to the numerical value lower than design object with the spurious alarm probability, but because existing method has been used the irrelevant fixed threshold with SNR, existing method also can't use different threshold values to change the detection performance.

If there is not effective testing mechanism, battery power can consume manyly, and high Loss Rate also is inevitably, thereby causes the communication performance of difference.Therefore, need to improve the existing method that detects Paging Indicator.

Summary of the invention

In view of the foregoing, the invention provides the method that in wireless communication system, detects Paging Indicator.

Herein disclosed is and utilize multistage and many threshold test mechanism to detect Paging Indicator, so that can suitably make portable terminal break away from the method and system of idle pulley.After receiving first Paging Indicator, determine to measure whether between first and second predetermined thresholds with corresponding first designator of first Paging Indicator.If, derive second designator tolerance according to second Paging Indicator, once more the nondecreasing function of first and second Paging Indicators tolerance is compared with the 3rd predetermined threshold, wherein, first and second predetermined thresholds based on the square root of the signal to noise ratio of first Paging Indicator and the 3rd predetermined threshold based on the square root of the corresponding signal to noise ratio of second Paging Indicator.

Herein disclosed is a kind ofly in wireless communication system, detect Paging Indicator by paging channel, so that make portable terminal break away from the method for idle pulley.This method comprises the reception first Paging Indicator I1; Determine the first and second threshold value T based on the signal to noise ratio of first Paging Indicator ₁And T ₂If the signal to noise ratio of first Paging Indicator is lower than predetermined initial snr threshold, then first and second threshold values are different, otherwise first and second threshold values are identical; Derive and corresponding first Paging Indicator tolerance of first Paging Indicator x ₁In the first order according to x ₁Respectively with T ₁And T ₂Between the portable terminal of relatively determining whether will break away from idle pulley, if x ₁Less than T ₁, then portable terminal remains on idle pulley; If x ₁More than or equal to T ₂, then portable terminal breaks away from idle pulley; If x ₁At T ₁And T ₂Between, be illustrated in and can not determine in the first order whether portable terminal breaks away from idle pulley, then derive second Paging Indicator tolerance x according to the second Paging Indicator I2 that receives ₂, and in the second level according to the 3rd threshold value T ₃With x ₁And x ₂Nondecreasing function between the portable terminal of relatively determining whether will break away from idle pulley, if x ₁And x ₂Nondecreasing function less than T ₃, then portable terminal remains on idle pulley, otherwise portable terminal breaks away from idle pulley; Wherein, T ₁Boundary and T that the expression loss-tolerant is called out ₂The boundary of expression tolerance spurious alarm, T ₁And T ₂Be according to derive with the square root of the corresponding signal to noise ratio of first Paging Indicator and T3 be according to deriving with the square root of the corresponding signal to noise ratio of second Paging Indicator.

Herein disclosed is a kind ofly in wireless communication system, detect Paging Indicator by paging channel, so that make portable terminal break away from the system of idle pulley.This system comprises receiver, is used to receive first and second Paging Indicator I1 and the I2; The threshold value maker is used for determining the first and second threshold value T based on the signal to noise ratio of first Paging Indicator ₁And T ₂If the signal to noise ratio of first Paging Indicator is lower than predetermined initial snr threshold, then first and second threshold values are different, otherwise first and second threshold values are identical; Processor is used for deriving and corresponding first Paging Indicator tolerance of first Paging Indicator (x ₁), or derive second Paging Indicator according to the second Paging Indicator I2 that receives and measure x ₂Comparator is used in the first order according to x ₁Respectively with T ₁And T ₂Between the portable terminal of relatively determining whether will break away from idle pulley, if x ₁Less than T ₁, then portable terminal remains on idle pulley; If x ₁More than or equal to T ₂, then portable terminal breaks away from idle pulley; If x ₁At T ₁And T ₂Between, be illustrated in and can not determine in the first order whether portable terminal breaks away from idle pulley, and in the second level according to the 3rd threshold value T ₃With x ₁And x ₂Nondecreasing function between the portable terminal of relatively determining whether will break away from idle pulley, if x ₁And x ₂Nondecreasing function less than T ₃, then portable terminal remains on idle pulley, otherwise portable terminal breaks away from idle pulley; Wherein, T ₁Boundary and T that the expression loss-tolerant is called out ₂The boundary of expression tolerance spurious alarm, T ₁And T ₂Be according to derive with the square root of the corresponding signal to noise ratio of first Paging Indicator and T3 be according to deriving with the square root of the corresponding signal to noise ratio of second Paging Indicator.

In conjunction with the drawings specific embodiment of the present invention is carried out following description, structure of the present invention and method of operation, and other purpose of the present invention and advantage will be clearer.

Description of drawings

Fig. 1 be illustrate according to one embodiment of the invention based on the figure of the difference of the signal to noise ratio of the Paging Indicator of spurious alarm probability and corresponding two targets thresholds of lost-call probability;

Fig. 2 is that illustration is the flow chart that multistage Paging Indicator detects the judgement of being done according to one embodiment of the invention; With

Fig. 3 realizes the hardware schematic diagram that multistage Paging Indicator detects according to one embodiment of the invention.

Embodiment

Hereinafter will be provided at the detailed description of the method and system of the existence of determining the designator that on quick paging channel, transmits in the cordless communication network.Here the theme of Chan Shuing can be applicable to utilize the wireless communication system of the multiplex signal of time division multiplexing (TDM), code division multiplex (CDM) and frequency division multiplex (FDM) technology.For the purpose of illustrating, the CDMA2000 system is used as an example.In the wireless communication system as the CDMA2000 system, several Paging Indicators have been realized.Those of ordinary skill in the art can be interpreted as Paging Indicator the signal of the existence that detects paging signal and be broadly defined as and comprise following Paging Indicator example, but be not limited to these.For example, a quick paging channel Paging Indicator is quick paging channel (QPCH) design.Another quick paging channel configuration variation designator is public control channel (CCCH) design.Another quick paging channel broadcast indicator is Broadcast Control Channel (BCCCH) design.

The present invention estimates the SNR of QPCH and calculates detection threshold according to the SNR that estimates.The working range of SNR is divided into two scopes: high SNR scope and low SNR scope.For each scope, the SNR dependent thresholds is used for different decision mechanisms.For example, in high SNR scope,, just can satisfy track rejection detection probability and target spurious alarm probability with single threshold value because signal quality is good.In fact, high SNR scope makes detector can enough single SNR dependent thresholds satisfy detection performance between loss detection probability and the spurious alarm probability.More particularly, in high SNR scope, use double decision mechanism.In low SNR scope, can not satisfy track rejection detection probability and target spurious alarm probability with single threshold value.Therefore, be necessary to use two threshold values, this has introduced suspection (erasure) or nondeterministic statement.When first Paging Indicator entered this and suspects state, test Paging Indicator subsequently was so that detected and itself and the first call loss designator may be combined.Therefore, in low SNR scope, use triple decision mechanisms.

According to one embodiment of the present of invention, each paging time-slot in the CDMA2000 system sends two Paging Indicator I1 and I2 in the cycle, and wherein, I2 is the time diversity counter pair of I1.These two designators are crossed over channel coherence length (approximately 20ms) to obtain time diversity.Suppose that the receiving symbol signal is expressed as r _{I, k, l}Wherein, i is that the Paging Indicator index is (for I1 or I2, be respectively 1 or 2), k comprises that the index and 1 of the multipath of diversity branch is Quadrature Phase Shift Keying (QPSK) symbol index, wherein, QPSK is interpreted as sending the digital frequency modulation technology of numerical data on communication channel, the estimation radio channel information of its correspondence is a _{I, k, l}, a _{I, k, l}Represent channel conditions.Then, can obtain and the corresponding measurement tolerance in paging bar display part by the predetermined combinations method.For example, by simple pilot weighted combined method, tolerance (or Paging Indicator tolerance) x is measured in three normalization ₁, x ₂And x ₃Be expressed as:

$x_1=\frac{\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{K1}{\mathrm{\&Sigma;}}}(\mathrm{Re}(a_{1,k,l}^{*}\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">r</figure-callout>}}_{1,k,l})+\mathrm{Im}(a_{1,k,l}^{*}\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">r</figure-callout>}}_{1,k,l}))}{\mathrm{QPR}\&CenterDot;\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{K}{\mathrm{\&Sigma;}}}{\left|a_{1,k,l}\right|}^2}$ (equation 1)

$x_2=\frac{\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{K2}{\mathrm{\&Sigma;}}}(\mathrm{Re}(a_{2,k,l}^{*}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">r</figure-callout>}}_{2,k,l})+\mathrm{Im}(a_{2,k,l}^{*}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">r</figure-callout>}}_{2,k,l}))}{\mathrm{QPR}\&CenterDot;\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{K}{\mathrm{\&Sigma;}}}{\left|a_{2,k,l}\right|}^2}$ (equation 2)

$x_3=\frac{\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{K1}{\mathrm{\&Sigma;}}}(\mathrm{Re}(a_{1,k,l}^{*}\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">r</figure-callout>}}_{1,k,l})+\mathrm{Im}(a_{1,k,l}^{*}\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">r</figure-callout>}}_{1,k,l}))+\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{K2}{\mathrm{\&Sigma;}}}(\mathrm{Re}(a_{2,k,l}^{*}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">r</figure-callout>}}_{2,k,l})+\mathrm{Im}(a_{2,k,l}^{*}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">r</figure-callout>}}_{2,k,l}))}{\mathrm{QPR}(\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{K1}{\mathrm{\&Sigma;}}}{\left|a_{1,k,l}\right|}^2+\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{K2}{\mathrm{\&Sigma;}}}{\left|a_{2,k,l}\right|}^2)}$ (equation 3)

Wherein, K1 and K2 are respectively the quantity of the multipath (comprising diversity branch) of I1 and I2, L is the quantity of the QPSK code element of each Paging Indicator, and QPR is ratio between the power of Quick Paging designator and pilot signal and the channel gain that is also referred to as the base station notice.In the CDMA2000 system, QPR has QPR=10 ^{(QPCH_POWER_LEVEL_PAGE+3)/20}Mathematical notation and QPCH_POWER_LEVEL_PAGE be with respect to the Paging Indicator modulated symbol power level that also is defined in the forward pilot channel in the CDMA2000 standard.

Should be understood that measuring tolerance is to derive according to the channel gain of base station notice, the radio channel information of estimation obviously is better than prior art.Said method can be called pilot tone weight combined method.Utilize this method,, do not solve noise problem so there is clear and definite designated noise to reduce weight owing to reached the effect of weighting.Just as illustrated, because x ₁, x ₂And x ₃All be the function of QPR and, so there is the built-in intrinsic adaptation mechanism that to work with any communication system to QPR normalization.Top The Representation Equation provide a normalization process with the corresponding summation of radio channel information so that can simplify analysis.It is also to be understood that measuring tolerance may not normalization, in fact, can determine to plan with measure tolerance threshold value relatively in take in (back will further specify) to QPR.By when deriving and analyzing these measurement tolerance and their respective threshold, taking all factors into consideration QPR and signal to noise ratio (snr), can use factor representation channel conditions and channel configuration, so that make paging detect the various channel environment of self adaptation fully.

In another embodiment that uses the high specific combined method, provide three similar normalization designators tolerance x by following ₁, x ₂And x ₃:

$x_1=\frac{\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{K1}{\mathrm{\&Sigma;}}}(\mathrm{Re}\left(\frac{a_{1,k,l}^{*}\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">r</figure-callout>}}_{1,k,l}}{{\mathrm{\&sigma;}}_{1,k,l}^2}\right)+\mathrm{Im}\left(\frac{a_{1,k,l}^{*}\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">r</figure-callout>}}_{1,k,l}}{{\mathrm{\&sigma;}}_{1,k,l}^2}\right))}{\mathrm{QPR}\&CenterDot;\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{K}{\mathrm{\&Sigma;}}}\frac{{\left|a_{1,k,l}\right|}^2}{{\mathrm{\&sigma;}}_{1,k,l}^2}}$ (equation 1 ')

$x_2=\frac{\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{K2}{\mathrm{\&Sigma;}}}(\mathrm{Re}\left(\frac{a_{2,k,l}^{*}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">r</figure-callout>}}_{2,k,l}}{{\mathrm{\&sigma;}}_{2,k,l}^2}\right)+\mathrm{Im}\left(\frac{a_{2,k,l}^{*}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">r</figure-callout>}}_{2,k,l}}{{\mathrm{\&sigma;}}_{2,k,l}^2}\right))}{\mathrm{QPR}\&CenterDot;\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{K}{\mathrm{\&Sigma;}}}\frac{{\left|a_{2,k,l}\right|}^2}{{\mathrm{\&sigma;}}_{2,k,l}^2}}$ (equation 2 ')

$x_3=\frac{\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{K1}{\mathrm{\&Sigma;}}}(\mathrm{Re}\left(\frac{a_{1,k,l}^{*}\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">r</figure-callout>}}_{1,k,l}}{{\mathrm{\&sigma;}}_{1,k,l}^2}\right)+\mathrm{Im}\left(\frac{a_{1,k,l}^{*}\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">r</figure-callout>}}_{1,k,l}}{{\mathrm{\&sigma;}}_{1,k,l}^2}\right))+\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{K}{\mathrm{\&Sigma;}}}(\mathrm{Re}\left(\frac{a_{2,k,l}^{*}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">r</figure-callout>}}_{2,k,l}}{{\mathrm{\&sigma;}}_{2,k,l}^2}\right)+\mathrm{Im}\left(\frac{a_{2,k,l}^{*}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">r</figure-callout>}}_{2,k,l}}{{\mathrm{\&sigma;}}_{2,k,l}^2}\right))}{\mathrm{QPR}(\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{K1}{\mathrm{\&Sigma;}}}\frac{{\left|a_{1,k,l}\right|}^2}{{\mathrm{\&sigma;}}_{1,k,\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">l</figure-callout>}}^2}+\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}\underset{k=1}{\overset{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">K</figure-callout>}2}{\mathrm{\&Sigma;}}}\frac{{\left|a_{2,k,l}\right|}^2}{{\mathrm{\&sigma;}}_{2,k,l}^2})}$ (equation 3 ')

Wherein,

It is the noise variance of i Paging Indicator, k multipath and the 1st code element.At this derivation x ₁, x ₂And x ₃Method in, the noise factor representation, and with due regard to the application weight.In general, if noise is higher, uses weight and just should hang down.As can be seen, noise variance is placed in the denominator part, with expression " inverse ratio " relation from top tolerance.In this high specific combined method, as described above, use certain weights and reduce noise jamming, thus the performance of raising system.

The effective signal-to-noise ratio of Paging Indicator I1 and I2 (SNR) is hereinafter referred to as SNR1 and SNR2.SNR3 is defined as the combination S NR of I1 and I2.In communication system, those of ordinary skill in the art should be understood that SNR often decides on characteristic, channel status and the intrinsic noise of portable terminal demodulator.For using, owing to can know QPCH power in advance according to pilot channel power, so SNR can use instead with Eb/Nt, Eb/Nt is the ratio of every potential energy and effective noise spectrum density.

Any decision rule of determining Paging Indicator all needs certain SNR estimated form.For example, can from pilot signal, estimate SNR.Total received power interference ratio Ec _p/ Io is a unit with decibel (dB), wherein, and Ec _pBe respectively the pilot chip energy and comprise signal and disturb both total reception input power spectrum densities with Io.This ratio can easily obtain from the mobile terminal to search device.Then, the noise factor of representing with SNR provides by following formula:

SNR=QPCH_Ec/Ioc=(QPR) ²* Ee _p/ Io (equation 4)

Wherein, Ec _pWith Ioc be the chip energy of pilot signal and band-limited white noise and the power spectral density that comprises that multipath disturbs from the interference of other sub-district.QPCH_Ec is total chip energy of Paging Indicator.Because I _o=I _Or+ I _Oc, for I _Or≌ I _OcThe poor radio channel conditions, can obtain approximate formula I _Oc≌ I _o/ 2, wherein, an I _OrBe that channel sends the back power spectral density.In forward link, I _OrIt is total transmit power spectral density of base station under soft handover.In the CDMA2000 system, I _Or/ I _OcBe called geometrical factor.

Therefore, the SNR approximate formula of I1 and I2 is as follows:

SNR1=2R* (QPR) ²* Ec _P1/ I _O1(equation 5)

SNR2=2R* (QPR) ²* Ec _P2/ I _O2(equation 6)

The SNR approximate formula of combination I1 and I2 is as follows:

SNR3=2R* (QPR) ²* [Ec _P1/ I _O1+ Ec _P2/ I _O2] (equation 7)

Wherein, for the CDMA2000 system, for 4,800bps or 2, the quick paging channel data rate of 400bps, R=256 or 512.When signal equaled noise-plus-interference, approximate error approximately was zero.As geometrical factor (I _Or/ I _Oc) low (for example, from-5db to 5dB) its estimate relatively accurate corresponding to low SNR district with mainly to detecting and decoding when very important.In the decision rule that is discussed below, decision threshold is a constant in the high SNR district corresponding to high geometrical factor.

With designator SNR that estimates and the SNR threshold that determines the boundary between high SNR scope and the low SNR scope.The SNR threshold value is the SNR that target spurious alarm probability and track rejection detection probability can both satisfy in first designator detects.Given spurious alarm probability (P _F) and loss detection probability (P _MD), by finding the solution the SNR threshold value that following associating equation obtains the SNR scope division is become high SNR or low SNR:

$P_F=\frac{1}{\sqrt{2\mathrm{\&pi;}}}{\&Integral;}_T^{\&infin;}\exp (-\frac{{\mathrm{<figure-callout\; id="2"\; label="x"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">x</figure-callout>}}^2}{2})\mathrm{dx}$

$P_{\mathrm{MD}}=\frac{1}{\sqrt{2\mathrm{\&pi;}}}{\&Integral;}_{-\&infin;}^{T-\sqrt{\mathrm{SNR}}}\exp (-\frac{{\mathrm{<figure-callout\; id="2"\; label="x"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">x</figure-callout>}}^2}{2})\mathrm{dx}$ (equation 8)

Wherein, " T " is that threshold value and x are designators.Substantially, T can from predetermined spurious alarm probability, derive and above SNR in the equation can derive according to T and predetermined loss detection probability.Like this, threshold value is that SNR is relevant.

Fig. 1 is the diagrammatic representation that illustrates according to the selection zone of the high SNR scope of an example of the present invention.As shown in Figure 1, the SNR dependent thresholds can be represented with the function of the square root (trunnion axis) of designator SNR.If threshold value is represented with linear function, then can obtain selected detection performance by slope and the intercept of adjusting threshold value.In high SNR scope, only need a detection threshold.Satisfy the threshold value (T of given spurious alarm probability _f) be and constant (shown in dotted line) that SNR is irrelevant, and satisfy the threshold value (T of given loss detection probability _d) be the subduplicate linear function (shown in solid line) of SNR.Detection threshold in the high SNR scope can be regarded as and surpass T to the right _fAnd T _dIntersection point at T _fAnd T _dBetween the zone in the subduplicate nondecreasing function of SNR.For the purpose of illustration, show this specific region that any detection threshold of high SNR can coincide with it with shade.

When in low SNR scope, detection is the multistage testing mechanism that detects at least two Quick Paging designators with compound mode.In order to detect Paging Indicator, need two threshold value T according to SNR ₁And T ₂, but, need the 3rd threshold value T for detection based on the combined pager designator ₃T ₁The boundary that the expression loss-tolerant is called out, and T ₂The boundary of expression tolerance spurious alarm.According to an example of the present invention, the detection threshold in low SNR scope is determined and can be elected as:

T ₁＝T _d

T ₂=T _f(equation 9)

${\mathrm{<figure-callout\; id="3"\; label="T"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">T</figure-callout>}}_3=f({\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">T</figure-callout>}}_1,{\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">T</figure-callout>}}_2,\sqrt{{(E_s/N_t)}_1}\sqrt{{(E_s/N_t)}_2})$

Wherein, f is a nondecreasing function.

If with threshold value T ₃Be expressed as linear function, can be with T ₃Be shown as:

${\mathrm{<figure-callout\; id="3"\; label="T"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">T</figure-callout>}}_3=a_3({\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">T</figure-callout>}}_1,{\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">T</figure-callout>}}_2,\sqrt{{(E_s/N_t)}_1})\sqrt{{(E_s/N_t)}_2}+b_3({\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">T</figure-callout>}}_1,{\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">T</figure-callout>}}_2,\sqrt{{(E_s/N_t)}_1})$ (equation 10)

Wherein, along with a ₃And b ₃Calculate in advance and they are kept in the memory, be used for given area (E _s/ N _t) 1 SNR scope is divided into several zones.

Fig. 2 provides illustration flow process Figure 100 according to the improvement testing process of one embodiment of the invention.In Fig. 2, x ₁And x ₂Be the first and second designator detection metric, and x ₁₂Be combined indication character tolerance (x ₁₂=w1*x ₁+ w2*x ₂, wherein, w1 and w2 are optional weights).(E _s/ N _t) ₁Be first designator code element energy noise ratio and the (E _s/ N _t) ₂It is the second designator code element energy noise ratio.SNR_threshold is total SNR threshold value, and T ₁, T ₂And T ₃Be three threshold values as discussed above.a ₁, a ₂And a ₃Be the constant of representing the slope of linear function, and b ₁, b ₂And b ₃Expression T _fAnd T _dBetween intercept.

Flow process Figure 100 is from entering the first order of determination step 102.If total SNR of QPCH is (that is QPCH (E, _s/ N _t) ₁) be not less than and be scheduled to based on total SNR threshold value SNR_threshold, then with T ₁And T ₂Value be arranged to identical value and in step 104, on mathematics, be specified to:

${\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">T</figure-callout>}}_1={\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">T</figure-callout>}}_2=a_{12}\sqrt{{(E_s/N_t)}_1}+b_{12}$ (equation 11)

On the other hand, if total SNR of QPCH is (that is QPCH (E, _s/ N _t) ₁) less than predetermined based on total SNR threshold value SNR_threshold, in step 106 with T ₁And T ₂Value be arranged to different value and on mathematics, be specified to:

${\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">T</figure-callout>}}_1=a_1\sqrt{{(E_s/N_t)}_1}+b_1$ With ${\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">T</figure-callout>}}_2=a_2\sqrt{{(E_s/N_t)}_1}+b_2$ (equation 12)

As can be seen, although still only according to first designator, T ₁And T ₂Be configured to different value based on different weight constant a and b.Along with T ₁And T ₂Obtain initial setting up, process forwards step 108 to, in step 108, with the first designator detection metric x ₁With the T that is provided with ₁Compare, if it is less than T ₁, then portable terminal should rest on idle condition (step 110).If in step 108, determine the first designator detection metric x ₁Greater than T ₁, then in step 112, further determine the first designator detection metric x ₁Whether more than or equal to T ₂If then in step 114, there is the strong indication that open portable terminal.This means, if the first designator detection metric x ₁Greater than T ₁And T ₂Both can not be spurious alarms.

At x ₁At T ₁And T ₂Between situation under, introduce the second designator detection metric x ₂Do further to detect.The second designator detection metric x ₂Derive from the second Paging Indicator I2, the second Paging Indicator I2 can be the time counter pair of the first Paging Indicator I1.At first derive combined threshold value T according to the square root of the SNR of second Paging Indicator ₃That is to say,

${\mathrm{<figure-callout\; id="3"\; label="T"\; filenames="S071D7390720070806E000011.png"\; state="\{\{state\}\}">T</figure-callout>}}_3=a_3\sqrt{{(E_s/N_t)}_2}+b_3$ (equation 13)

Wherein, a ₃And b ₃It all is the predetermined constant that can be stored in advance in the portable terminal.Then, will be in step 116 with x as its variable ₁And x ₂The selected nondecreasing function f and the T that change ₃Compare.If in step 116, determine to be lower than threshold value T ₃, so, turning-off mobile terminal.Otherwise, in step 120, open portable terminal.Arrive this, finished two-stage designator testing process.

Should be noted that in step 102, SNR_threshold is the artificial dividing line that the working range of SNR is cut into high SNR scope and low SNR scope.As mentioned above, if be in the high SNR scope, single threshold value is enough to satisfy track rejection detection probability and target spurious alarm probability.On the other hand,, then think to be in the low SNR scope, need to use triple decision processes if be lower than total threshold value.Two different threshold value T ₁And T ₂Introduced x ₁Greater than T ₁But less than T ₂The suspection state.This moment, have reason to think,, should introduce and further determine and second designator is used for further judgement whether should open portable terminal as from top step 116, seeing.Be to be further noted that T ₁, T ₂And T ₃Value all some based on the square root of the SNR of Paging Indicator separately.

Fig. 3 illustration contain various components to finish the hardware schematic diagram 300 that Paging Indicator detects.In portable terminal, exist to receive the QPCH signal, and from the signal receiver or the detector 302 of other signal of other communication channel as the pilot channel.At least one comparator module 304 is in the portable terminal, and it carries out many wheels relatively as described above.The processing that SNR calculator 306 provides the SNR value according to received signal and threshold value maker 308 calculates required threshold value.In the time of when make SNR and threshold value feed-in comparator according to detection signal in, comparator compares with cooperating as the processing unit of microcontroller 310.According to comparative result, controller 310 provides and portable terminal is waken up or rests on the decision signal of idle condition.It is also to be understood that various calculators and maker can be realized with hardware or software approach.For example, all disposal abilities can not resolve into different units ground is provided by the microprocessor as the controller in the portable terminal.Alternately, certain module can be realized by the discrete hardware module that works alone with controller.

Top illustration provides many different embodiment or has realized the embodiment of different characteristic of the present invention.The specific embodiment of describing these parts and process helps to illustrate the present invention.Certainly, these are embodiment only, do not plan with the present invention be constrained to be different from claims described those.

Although illustration and described the present invention here in being embodied in one or more special cases, but the details shown in the present invention is not limited to is not because can depart from the present invention's spirit ground and make various modifications and structural change in the scope of claims or equivalent.So,, be appropriate briefly with understanding appended claims in the mode consistent with scope of the present invention as described in the appended claims.

Claims (10)

1. One kind in wireless communication system, detect Paging Indicator by paging channel so that make portable terminal break away from the method for idle pulley, this method comprises:

   Receive the first Paging Indicator I1;

   Determine the first and second threshold value T based on the signal to noise ratio of first Paging Indicator ₁And T ₂If the signal to noise ratio of first Paging Indicator is lower than predetermined initial snr threshold, then first and second threshold values are different, otherwise first and second threshold values are identical;

   Derive and corresponding first Paging Indicator tolerance of first Paging Indicator x ₁

   In the first order according to x ₁Respectively with T ₁And T ₂Between the portable terminal of relatively determining whether will break away from idle pulley, if x ₁Less than T ₁, then portable terminal remains on idle pulley; If x ₁More than or equal to T ₂, then portable terminal breaks away from idle pulley; If x ₁At T ₁And T ₂Between, be illustrated in and can not determine in the first order whether portable terminal breaks away from idle pulley, then derive second Paging Indicator tolerance x according to the second Paging Indicator I2 that receives ₂And

   In the second level according to the 3rd threshold value T ₃With x ₁And x ₂Nondecreasing function between the portable terminal of relatively determining whether will break away from idle pulley, if x ₁And x ₂Nondecreasing function less than T ₃, then portable terminal remains on idle pulley, otherwise portable terminal breaks away from idle pulley;

   Wherein, T ₁Boundary and T that the expression loss-tolerant is called out ₂The boundary of expression tolerance spurious alarm, T ₁And T ₂Be according to derive with the square root of the corresponding signal to noise ratio of first Paging Indicator and T3 be according to deriving with the square root of the corresponding signal to noise ratio of second Paging Indicator.
2. 2. method according to claim 1 wherein, determines that the step of first and second threshold values further comprises if the signal to noise ratio of first Paging Indicator is lower than predetermined initial SNR threshold value, then with T ₁And T ₂Be defined as

   

   With

   

   Wherein,

   

   Be and the corresponding signal to noise ratio of first Paging Indicator, a ₁, a ₂, b ₁, b ₂It is predetermined constant.
3. 3. method according to claim 1 wherein, determines that the step of first and second threshold values further comprises if the signal to noise ratio of first Paging Indicator is higher than predetermined initial snr threshold, then with T ₁And T ₂Be defined as Wherein,

   

   Be and the corresponding signal to noise ratio of first Paging Indicator, a ₁₂And b ₁₂It is predetermined constant.
4. 4. method according to claim 1, wherein, the 3rd threshold value T ₃Be determined to be

   

   Wherein,

   

   Be and the corresponding signal to noise ratio of second Paging Indicator, and a ₃And b ₃It is predetermined constant.
5. 5. method according to claim 1, wherein, the second Paging Indicator I2 is the time diversity counter pair of the first Paging Indicator I1.
6. One kind in wireless communication system, detect Paging Indicator by paging channel so that make portable terminal break away from the system of idle pulley, this system comprises:

   Receiver is used to receive first and second Paging Indicator I1 and the I2;

   The threshold value maker is used for determining the first and second threshold value T based on the signal to noise ratio of first Paging Indicator ₁And T ₂If the signal to noise ratio of first Paging Indicator is lower than predetermined initial snr threshold, then first and second threshold values are different, otherwise first and second threshold values are identical;

   Processor is used for deriving and corresponding first Paging Indicator tolerance of first Paging Indicator (x ₁), or derive second Paging Indicator according to the second Paging Indicator I2 that receives and measure x ₂

   Comparator is used in the first order according to x ₁Respectively with T ₁And T ₂Between the portable terminal of relatively determining whether will break away from idle pulley, if x ₁Less than T ₁, then portable terminal remains on idle pulley; If x ₁More than or equal to T ₂, then portable terminal breaks away from idle pulley; If x ₁At T ₁And T ₂Between, be illustrated in and can not determine in the first order whether portable terminal breaks away from idle pulley, and in the second level according to the 3rd threshold value T ₃With x ₁And x ₂Nondecreasing function between the portable terminal of relatively determining whether will break away from idle pulley, if x ₁And x ₂Nondecreasing function less than T ₃, then portable terminal remains on idle pulley, otherwise portable terminal breaks away from idle pulley;

   Wherein, T ₁Boundary and T that the expression loss-tolerant is called out ₂The boundary of expression tolerance spurious alarm, T ₁And T ₂Be according to derive with the square root of the corresponding signal to noise ratio of first Paging Indicator and T3 be according to deriving with the square root of the corresponding signal to noise ratio of second Paging Indicator.
7. 7. system according to claim 6, wherein, the second Paging Indicator I2 is the time diversity counter pair of the first Paging Indicator I1.
8. 8. system according to claim 6, wherein, if the signal to noise ratio of first Paging Indicator is lower than predetermined initial snr threshold, the then first and second threshold value T ₁And T ₂Be defined by

   

   With

   

   Wherein,

   

   Be and the corresponding signal to noise ratio of first Paging Indicator, a ₁, a ₂, b ₁, b ₂It is predetermined constant.
9. 9. system according to claim 6, wherein, if the signal to noise ratio of first Paging Indicator is higher than predetermined initial snr threshold, the then first and second threshold value T ₁And T ₂Be configured to identical and be arranged to

   

   Wherein, Be and the corresponding signal to noise ratio of first Paging Indicator, a ₁₂And b ₁₂It is predetermined constant.
10. 10. system according to claim 6, wherein, the 3rd threshold value T ₃Be determined to be Wherein,

    

    Be and the corresponding signal to noise ratio of second Paging Indicator, and a ₃And b ₃It is predetermined constant.

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