CN101651464A - Activation code detection method and device - Google Patents

Abstract

Disclosed is an activation code detection method and device. A method for detecting activation code from the activation window of the received signal in a descending link receiver used in a communicating system, includes the following steps: a matched filtering step, fro performing matched filtering to the received signal to achieve the filtering output of each of a plurality of code channels in the activation window; a code channel power calculation step, using the filtering output of the code channel to calculate the power of the code channel according to each code channel; a compensating factor calculation step, using the spread-spectrum code and channel impulse response of the code channel to calculate the compensating factor of the code channel according to each code channel; a powercompensation step, for obtaining the compensated power of the code channel by dividing the power of the code channel by the compensating factor of the code channel according to each code channel; andan activation code detection step, detecting the activated code channel according to the compensated power of each code channel.

Description

Activation code detection method and device

Technical field

Relate generally to TD SDMA of the present invention (TD-SCDMA) wireless communication system more specifically, the present invention relates to activation code detection method and device in the TD-SCDMA receiver.

Background technology

TD-SCDMA is the 3G (Third Generation) Moblie air interface standard that the Chinese Industrial Standards (CIS) tissue is submitted to International Telecommunication Association.It is received by International Telecommunication Association, and is written into international norm as the part of CDMA-TDD pattern.Its key technology that adopts comprises: synchronization CDMA, smart antenna, joint-detection, software radio, baton handover etc.The TD-SCDMA system adopts time division duplex (TDD) pattern, and uplink and downlink are that the different time-gap at same carrier frequency transmits, and separate with the protection interval between the upstream and downstream channel, have the TDMA characteristic.In the TD-SCDMA system, some users can send a plurality of different bursts at same time slot.Different spreading codes makes that signal can be separated at the receiver place.According to required data rate, the user can use some code channels and/or time slot.Because the multipath effect of mobile channel and the correlation between the user, TD-SCDMA system exist intersymbol interference and multiple access to disturb.For this reason, the TD-SCDMA receiver is adopting training sequence to carry out on the basis of channel estimating, make full use of all users' relevant prior information (as each user's spread spectrum code sequence and correlation etc.), all users' combined signal is got up to detect, to reduce above-mentioned interference.

The channel impulse response that is obtained by channel estimating can be divided into the window corresponding to different training sequences.Receiver activates can know that just which window activates after window detects.In the window a plurality of code channels can be arranged, these code channels differ to establish a capital and are used, and promptly differ to establish a capital and activate.The code channel of non-activation window is generally considered to be nonactivated.And the code channel of activation window still needs further to detect to determine which code channel be certain activation.The purpose that active coding detects is exactly to detect the code channel of active coding to determine to activate that activates in the window.

According to the code channel method of salary distribution of TD-SCDMA, all there is a code channel that must use in each window, and is called first-selected code channel.Traditional detection active coding mode only compares the matched filter power output of first-selected code channel and the matched filter power output of other code channels simply.Yet,, all the more so under harsh conditions because wireless environment pollution to received signal usually contains noise in the signal that receives..And to the received signal receiver is handled the power that can change each channel respectively before detecting active coding.These factors have caused the decline of active coding accuracy of detection.

Summary of the invention

Consider the problems referred to above, the invention discloses in the communication system down link link receiver, from the activation window of received signal, detect the method and apparatus of active coding more accurately.

According to an aspect of the present invention, providing a kind of is used at the communication system down link link receiver, from the activation window of received signal, detect the method for active coding, may further comprise the steps: the matched filtering step, carry out matched filtering to received signal to obtain activating each filtering output of a plurality of code channels in the window; Code channel power calculation step at each code channel, uses the filtering of this code channel to export the power that calculates this code channel; The compensating factor calculation procedure at each code channel, is used the spreading code and the channel impulse response of this code channel, calculates the compensating factor of this code channel; The power back-off step at each code channel, by with the power of this code channel compensating factor divided by this code channel, obtains the power after the compensation of this code channel; And active coding detects step, detects the code channel of activation according to the power after the compensation of each code channel.Wherein, described a plurality of code channels comprise a known first-selected code channel and one or more non-first-selected code channel, and first-selected code channel activates; Active coding detects step and comprises that further power ratio calculation procedure and code channel detect step, and described power ratio calculation procedure is calculated the ratio of the power after the compensation of power and described first-selected code channel after the compensation of each described non-first-selected code channel respectively; Described code channel detects step, described power ratio is detected more than or equal to the spreading code of the code channel of a detection threshold be active coding, described power ratio is detected less than the spreading code of the code channel of described detection threshold be non-active coding.

According to an aspect of the present invention, providing a kind of is used at the communication system down link link receiver, from the activation window of received signal, detect the method for active coding, may further comprise the steps: the matched filtering step, carry out matched filtering to received signal, to obtain activating each the filtering output vector of plural form of a plurality of code channels in the window; Vector rotation step, the element that the filtering output vector of each code channel is comprised carries out 45 degree phase places rotations, obtains postrotational output vector; Soft information obtaining step extracts the real part and the imaginary part of the postrotational output vector of each code channel, and calculates their absolute value respectively, thereby obtains the soft information vector of the real number form of this code channel; The median calculation step at each code channel, is calculated the intermediate value of each element that soft information vector comprises; Soft erasing of information step, for each code channel, element littler than the intermediate value that calculates at this code channel in the median calculation step in the soft information vector with this code channel is changed to 0, the soft information vector after removing with acquisition; Code channel power calculation step at each code channel, uses soft information vector after the removing of this code channel to calculate the power of this code channel; And active coding detects step, and the power of each code channel that calculates according to code channel power calculation step detects the code channel of activation.Wherein, described a plurality of code channels comprise a known first-selected code channel and one or more non-first-selected code channel, and first-selected code channel activates; Active coding detects step and comprises that further power ratio calculation procedure and code channel detect step, described power ratio calculation procedure is calculated the power of each described non-first-selected code channel and the ratio of the power of described first-selected code channel respectively, the step that detects described code channel detects described power ratio and is active coding more than or equal to the spreading code of the code channel of a detection threshold, described power ratio is detected less than the spreading code of the code channel of described detection threshold be non-active coding.

According to a further aspect of the invention, a kind of being used at the communication system down link link receiver, from the activation window of received signal, detect the device of active coding, comprise: the matched filtering module, carry out matched filtering to received signal to obtain activating each filtering output of a plurality of code channels in the window; The code channel power computation module at each code channel, uses the filtering of this code channel to export the power that calculates this code channel; The compensating factor computing module at each code channel, uses the spreading code and the channel impulse response of this code channel, calculates the compensating factor of this code channel; The power back-off module at each code channel, by with the power of this code channel compensating factor divided by this code channel, obtains the power after the compensation of this code channel; And the active coding detection module, detect the code channel of activation according to the power after the compensation of each code channel.Wherein, described a plurality of code channels comprise a known first-selected code channel and one or more non-first-selected code channel, and first-selected code channel activates; The active coding detection module further comprises power ratio computing module and code channel detection module, and described power ratio computing module calculates the ratio of the power after the compensation of power and described first-selected code channel after the compensation of each described non-first-selected code channel respectively; Described code channel detection module detects described power ratio and to be active coding more than or equal to the spreading code of the code channel of a detection threshold, described power ratio is detected less than the spreading code of the code channel of described detection threshold be non-active coding.

According to a further aspect of the invention, providing a kind of is used at the communication system down link link receiver, from the activation window of received signal, detect the method for active coding, comprise with lower module: the matched filtering module, carry out matched filtering to received signal, to obtain activating each the filtering output vector of plural form of a plurality of code channels in the window; The vector rotary module, the element that the filtering output vector of each code channel is comprised carries out 45 degree phase places rotations, obtains postrotational output vector; Soft information acquisition module extracts the real part and the imaginary part of the postrotational output vector of each code channel, and calculates their absolute value respectively, thereby obtains the soft information vector of the real number form of this code channel; The median calculation module at each code channel, is calculated the intermediate value of each element that soft information vector comprises; Soft erasing of information module, for each code channel, element littler than the intermediate value that calculates at this code channel in the median calculation module in the soft information vector with this code channel is changed to 0, the soft information vector after removing with acquisition; The code channel power computation module at each code channel, uses soft information vector after the removing of this code channel to calculate the power of this code channel; And the active coding detection module, the power of each code channel that calculates according to the code channel power computation module detects the code channel of activation.Wherein, described a plurality of code channels comprise a known first-selected code channel and one or more non-first-selected code channel, and first-selected code channel activates; The active coding detection module further comprises power ratio computing module and code channel detection module, described power ratio computing module calculates the power of each described non-first-selected code channel and the ratio of the power of described first-selected code channel respectively, described code channel detection module detects described power ratio and is active coding more than or equal to the spreading code of the code channel of a detection threshold, described power ratio is detected less than the spreading code of the code channel of described detection threshold be non-active coding.

In sum, the present invention is when carrying out the active coding detection, take into account by handling the power of accumulating by receiver before active coding is detected, adjust judgement power before, and/or before judgement, reduce noise, come to carry out active coding and detect, thereby obtained more accurate testing result with higher precision.

Description of drawings

By with reference to the following accompanying drawing that only is used for the illustrative purpose, can more fully understand the present invention, wherein:

Fig. 1 is the brief block diagram of illustration TD-SCDMA wireless communication system;

Fig. 2 is the brief block diagram of the concrete structure of illustration subscriber equipment shown in Figure 1;

Fig. 3 is the schematic diagram of the structure of channel matrix T in the illustration TD-SCDMA data reception signal model;

Fig. 4 illustrates the block diagram of active coding checkout gear according to an embodiment of the invention;

Fig. 5 illustrates the flow chart of activation code detection method according to an embodiment of the invention;

Fig. 6 illustrates the block diagram of active coding checkout gear in accordance with another embodiment of the present invention; And

Fig. 7 illustrates the flow chart of activation code detection method in accordance with another embodiment of the present invention;

Embodiment

To describe the feature and the exemplary embodiment of various aspects of the present invention below in detail.In the following detailed description, illustration many details so that those skilled in the art can understand the present invention all sidedly.But, it is apparent that some details that enforcement of the present invention can be in not needing these details.To the description of specific embodiment only as example and unrestricted providing.The various modifications of example described herein and combination are apparent for a person skilled in the art, and the General Principle of definition here may be used in other examples and the application under the premise without departing from the spirit and scope of the present invention.Therefore, do not plan to limit the present invention on the example of describing and illustrating, but give the wide region that it meets principle disclosed herein and feature.For not fuzzy understanding, be not shown specifically known structure and technology to this description.

Fig. 1 shows the brief block diagram of TD-SCDMA wireless communication system.As shown in Figure 1, this wireless communication system mainly comprises core net 102, wireless access network 104 and subscriber equipment 106.Core net 102 is main handle audio call, data connection and exchange, customer position information management, network characteristic and professional control, signaling and user profile transmission mechanism in the wireless communication systems, and with being connected and route etc. of other network.Wireless access network 104 provides being connected of subscriber equipment and core net, and the management of responsible Radio Resource and allotment, comprises base station and radio network controller two category nodes.Subscriber equipment 106 for example can be that mobile phone, PDA(Personal Digital Assistant) or other have the portable data treatment facility of the function that communicates in the TD-SCDMA wireless communication system.

Fig. 2 shows the brief block diagram of the concrete structure of subscriber equipment shown in Figure 1.As shown in Figure 2, this subscriber equipment mainly comprises: radio-frequency module 202, forming filter 204, channel estimation module 206, multipath tracking module 208 activates detection module 210, joint-detection module 212, frequency deviation estimating modules 214, ANR/SNR measurement module 216 is separated mapping (demapping) module 218 and decoder module 220.202 pairs of analog signals that received of radio-frequency module unload ripple and analog-to-digital conversion is handled, and are transformed to baseband digital signal with the analog signal that will be received and are input to subordinate.Forming filter 204, promptly root raised cosine filter (SRRC) carries out pulse shaping to baseband digital signal.Channel estimation module 206 carries out the channel estimating of a plurality of sub-districts for the midamble code sequence in the signal behind the pulse shaping.Multipath tracking module 208 is utilized channel estimation results, determines optimum sampling point, and carries out the multipath window position tracking of each sub-district.Activate detection module 210 and be used to carry out window activation detection and code channel activating detection.212 pairs of joint-detection modules are aliasing in the data of each code channel together and carry out certain calculating, obtain the transmission symbol on each code channel.Frequency deviation estimating modules 214 is utilized the skew of joint detection results estimated frequency.ANR/SNR measurement module 216 utilizes joint detection results to carry out amplitude and noise ratio (ANR) and signal to noise ratio (snr) is measured.Separating mapping (demapping) module 218 is that soft bit is delivered to decoder module with the symbol transition of joint-detection module output.220 pairs of decoder modules will be separated the soft bit result of mapping block output and decode, and obtain information bit.

The disclosure is primarily aimed at the detection that activates the active coding of carrying out in the detection module 210.Should be noted that, though provided above as depicted in figs. 1 and 2 the TD-SCDMA wireless communication system and the ios dhcp sample configuration IOS DHCP of subscriber equipment, but can recognize, can use communication system of the present invention and subscriber equipment to be not limited to this concrete example therein, but can be suitable for various systems and equipment that needs detect active coding.

Fig. 3 is the schematic diagram of the structure 300 of channel matrix T in the illustration TD-SCDMA data reception signal model, and wherein matrix-block V represents to be used to construct the fundamental matrix piece of channel matrix T.Below with reference to Fig. 3 the generative process of channel matrix T is carried out mathematical description.

[channel matrix T]

Make h _kExpression and k the channel impulse response (CIR) that code channel is relevant.

h _k＝[h _k ⁽¹⁾h _k ⁽²⁾…h _k ^(w)]，k＝1，2，……，K (1)

Wherein, K is for activating the code channel number in the window that is detected as activation after window detects, and W is the length of channel impulse response.

If with channel impulse response h _kThe relevant vectorial c of spreading code _kExpression, then c _kCan be expressed as following Q * 1 dimensional vector with following formula, Q is a spreading factor:

c _k＝w _k·OVSF _k·v _k，k＝1，2，……，K (2)

OVSF wherein _kThe channel code vector of expression Q * 1 dimension, w _kRepresent the multiplier vector relevant, v with channel code _kThe scrambler vector of expression Q * 1 dimension, wherein symbolic representation dot product promptly multiplies each other by element.

With channel impulse response h _kWith spreading code c _kUsing Convolution become vectorial b _k:

$b_k=c_k\⊗h_k,$ k＝1，2，……，K (3)

B then _kBe the column vector of (Q+W-1) * 1 dimension, represent equivalence to merge channel impulse response.

Note, here w _k, OVSF _kAnd v _kBe according to channel impulse response h _kArrange in communication system in advance affiliated code channel and sub-district.

(Q+W-1) * the matrix-block V of K dimension is made up of K column vector:

V＝[b ₁，b ₂，…，b _K](4)

Wherein each row is used for a code channel.Notice that code channel may be from different districts.

[output of matched filter]

Received signal can be expressed as the column vector r of following (NQ+W-1) * 1 dimension:

r＝Td+n (5)

Wherein, the column vector d of NK * 1 dimension represents the transmission signal from K code channel, and N is a number of chips, and n represents the random noise vector.T represents the channel matrix by (NQ+W-1) * NK dimension of matrix-block V structure, as shown in Figure 3.

Received signal r is imported in the filter that is complementary with channel (as known to the skilled person subsequently, this filter is also referred to as matched filter), this process can multiply by the output vector x that received signal vector r obtains matched filter with the conjugate transpose of channel matrix T to be represented:

x＝T ^Hr (6)

Convolution (5) makes received signal r by above-mentioned matched filter, is equivalent to make transmission signal d to multiply by matrix T ^HT.Because nearly orthogonal between each row of matrix-block V, bigger value only appears at matrix T ^HOn the diagonal of T.

The purpose that active coding detects is will detect among the output vector x of aforesaid matched filter to have which code channel to activate.According to the agreement regulation of TD-SCDMA, the first-selected code channel of an activation window always is considered to activate.Whether other code channels of this activation window are that what to activate is to decide by the matched filter power output of the matched filter power output of this code channel and first-selected code channel is made comparisons.Particularly, when the ratio of the matched filter power output of a code channel and the matched filter power output of first-selected code channel during greater than a certain threshold value, this code channel is considered to activate; Otherwise this code channel is considered to nonactivated.Wherein, threshold value as criterion is the empirical value that emulation obtains, and those skilled in the art can be according to using the demodulation performance (as block error rate BLER, error rate BER etc.) after this parameter or adjusting flexibly according to the detection performance of active coding (as the detection probability of active coding and false alarm probability etc.).

Fig. 4 illustrates the block diagram of active coding checkout gear according to an embodiment of the invention.This device compensates based on receiver power and carries out the active coding detection.As shown in Figure 4, active coding checkout gear 400 mainly comprises with lower module according to an embodiment of the invention: matched filtering module 401, carry out matched filtering to received signal to obtain activating each filtering output of a plurality of code channels in the window; Code channel power computation module 402 at each code channel, uses the filtering of this code channel to export the power that calculates this code channel; Compensating factor computing module 403 at each code channel, uses the spreading code and the channel impulse response of this code channel, calculates the compensating factor of this code channel; Power back-off module 404 at each code channel, by with the power of this code channel compensating factor divided by this code channel, obtains the power after the compensation of this code channel; And active coding detection module 405, detect the code channel of activation according to the power after the compensation of each code channel.

Fig. 5 illustrates the flow chart of activation code detection method 500 according to an embodiment of the invention, and this method compensates based on receiver power carries out the active coding detection, and its each step that comprises can be finished by the corresponding module of active coding checkout gear 400 respectively.Introduce each step that activation code detection method 500 comprises below in detail:

[step S501] carries out matched filtering to received signal to obtain activating each filtering output of a plurality of code channels in the window.

As mentioned above, this step is equivalent to multiply by the received signal vector r that activates after window detects with the conjugate transpose of channel matrix T, obtains the filtering output vector x of each code channel _k(1≤k≤K), wherein K is for activating the code channel number in the window that is detected as activation after window detects.

[step S502] uses the filtering of this code channel to export the power that calculates this code channel at each code channel.

To the filtering output vector x that in step S501, obtains _kEach component ask quadratic sum, then divided by the dimension N of vector, thereby obtain the power output p ' of the matched filter of k code channel _k, can represent with following formula:

$p_k^{\&prime;}=\underset{n=1}{\overset{N}{\mathrm{\&Sigma;}}}{\left|x_{k,n}\right|}^2/N(1\&le;k<K)$

Wherein, x _{K, n}Be filtering output vector x _kN component.

[step S503] uses the spreading code and the channel impulse response of this code channel at each code channel, calculates the compensating factor C of this code channel _k

At first, for each code channel, by spreading code b with this code channel _kWith channel impulse response h _kDo convolution, the equivalence of calculating this code channel merges channel impulse response b _k:

$b_k=c_k\&CircleTimes;h_k$

Then, merge channel impulse response b by calculating equivalence _kThe quadratic sum of mould value, calculate the compensating factor C of this code channel _k:

$C_k={(b_k^H\&times;b_k)}^2$

Wherein, subscript H represents conjugate transpose.

[step S504] at each code channel, by with the power of this code channel compensating factor divided by this code channel, obtains the power after the compensation of this code channel.

For each code channel, the power output p ' of the matched filter that will in step S502, obtain _kDivided by the compensating factor C that in step S503, obtains _k, obtain the power p after the compensation of this code channel _k, compensate thus by receiver and handle caused power excursion.This step can be expressed as:

p _k＝p′ _k/C _k

[step S505] power after according to the compensation of each code channel detects the code channel of activation.

Be designated as 1 under the first-selected code channel,, calculate its power p for non-first-selected code channel k _kWith first-selected code channel power p ₁Ratio r:

r＝p _k/p ₁

Then, decide according to following formula whether it is what activate:

$\mathrm{activeflag}=\left\{\begin{array}{cc}1& r\&GreaterEqual;{\mathrm{\&alpha;}}_1\\ 0& r<{\mathrm{\&alpha;}}_1\end{array}\right.$

Wherein, active flag represents activation marker, α ₁Be to be used for the threshold value that activated code channel detects, can obtain by emulation according to the standard such as detection probability, false alarm probability.

Fig. 6 illustrates the block diagram of active coding checkout gear in accordance with another embodiment of the present invention.This device reduces based on noise and carries out the active coding detection.As shown in Figure 6, active coding checkout gear 600 mainly comprises with lower module according to an embodiment of the invention: matched filtering module 601, described received signal is carried out matched filtering, to obtain each the filtering output vector of plural form of a plurality of code channels in the described activation window; Vector rotary module 602, the element that the filtering output vector of each code channel is comprised carries out 45 degree phase places rotations, obtains postrotational output vector; Soft information acquisition module 603 extracts the real part and the imaginary part of the postrotational output vector of each code channel, and calculates their absolute value respectively, thereby obtains the soft information vector of the real number form of this code channel; Median calculation module 604 at each code channel, is calculated the intermediate value of each element that soft information vector comprises; Soft erasing of information module 605 for each code channel, will be changed to 0 than the little element of intermediate value that calculates at this code channel in the described median calculation step in the soft information vector of this code channel, the soft information vector after removing with acquisition; Code channel power computation module 606 at each code channel, uses soft information vector after the removing of this code channel to calculate the power of this code channel; And active coding detection module 607, the power of each code channel that calculates according to described code channel power calculation step detects the code channel of activation.

Fig. 7 illustrates the flow chart of activation code detection method 700 in accordance with another embodiment of the present invention, and this method reduces based on noise and carries out the active coding detection, and its each step that comprises can be finished by the corresponding module of active coding checkout gear 600 respectively.Introduce each step that activation code detection method 700 comprises below in detail:

[step S701] carries out matched filtering to received signal to obtain activating each filtering output of a plurality of code channels in the window.

As mentioned above, this step is equivalent to multiply by the received signal vector r that activates after window detects with the conjugate transpose of channel matrix T, obtains the filtering output vector x of each code channel _k(1≤k≤K), wherein K is for activating the code channel number in the window that is detected as activation after window detects.

[step S702] is with the filtering output vector x of each code channel _kThe element that is comprised carries out 45 degree phase place rotations, obtains postrotational output vector v _k

With filtering output vector x _kIn each element multiply by (1-j) with rotate 45 the degree, can be expressed as:

v _k＝(1-j)·x _k

[step S703] extracts the postrotational output vector v of each code channel _kReal part and imaginary part, and calculate their absolute value respectively, thereby obtain the soft information vector a of the real number form of this code channel _k

This step can be expressed as:

$a_k=\mathrm{vec}\left[\begin{array}{c}\mathrm{abs}\left\{\mathrm{Re}\right[v_k\left]\right\}\\ \mathrm{abs}\left\{\mathrm{Im}\right[v_k\left]\right\}\end{array}\right]$

Wherein, vec[] expression is launched into vector with the content in [], Re[] expression gets real part, Im[] represent to get imaginary part, abs{} represents to take absolute value.

[step S704] calculates the soft information vector a of this code channel at each code channel _kIntermediate value med (a of each element that is comprised _k).

With soft information vector a _kEach component that comprises is arranged from big to small, because soft information vector a _kComprise the even number component, so intermediate value med (a _k) the mean value of two components in the middle of equaling to be positioned at.

[step S705] is for each code channel, with the soft information vector a of this code channel _kIn than the intermediate value med (a that calculates at this code channel in the described median calculation step _k) little element is changed to 0, with the soft information vector a ' after obtaining to remove _k

This step is in order to remove the noise of soft information in the code channel, can represent with following formula:

$a_{k,n}^{\&prime;}=\left\{\begin{array}{cc}{a}_{k,n}& a_{k,n}>\mathrm{med}\left(a_k\right)\\ 0& a_{k,n}\&le;\mathrm{med}\left(a_k\right)\end{array}\right.n=\mathrm{1,2},...,2N$

Wherein, a ' _{K, n}Be vectorial a ' _kN element, 2N is a ' _kDimension.

[step S706] at each code channel, uses the soft information vector a ' after the removing of this code channel _kCalculate the power p of this code channel _k

To the soft information vector a ' after the removing that in step S706, obtains _kEach component ask quadratic sum, then divided by in step S706 not by total number of the component of zero setting, thereby obtain the power p of this code channel _kThis step can be represented with following formula:

$p_k=\underset{n=1}{\overset{N_{\mathrm{rest}}}{\mathrm{\&Sigma;}}}{\left|a_{k,n}\right|}^2/N_{\mathrm{rest}}$

Wherein, a ' _{K, n}Be vectorial a ' _kN component, N _RestFor in step S706 not by total number of the component of zero setting.

[step S707] detects the code channel of activation according to the power of each code channel that calculates in step S706.

Be designated as 1 under the first-selected code channel,, calculate its power p for non-first-selected code channel k _kWith first-selected code channel power p ₁Ratio r:

r＝p _k/p ₁

Then, decide according to following formula whether it is what activate:

$\mathrm{activeflag}=\left\{\begin{array}{cc}1& r\&GreaterEqual;{\mathrm{\&alpha;}}_2\\ 0& r<{\mathrm{\&alpha;}}_2\end{array}\right.$

Wherein, active flag represents activation marker, α ₂Be to be used for the threshold value that activated code channel detects, can obtain by emulation that its representative value is 0.71 according to the standard such as detection probability, false alarm probability.

Above-mentioned activation code detection method 500 and activation code detection method 700 also can combine use, obtain based on the activation code detection method that noise reduces and receiver power compensates, to obtain higher accuracy of detection.

Be described with reference to the drawings above according to concrete examples more of the present invention.But the present invention does not really want any concrete configuration that is subjected to describing in the foregoing description and the restriction of process.Within the scope of spirit of the present invention, those skilled in the art can recognize various replacements, change or the modification of above-mentioned configuration, algorithm, operation and process.

The various method steps of describing in conjunction with the accompanying drawings more than can carrying out with hardware or software as required.Notice that without departing from the scope of the invention, the flow chart that can provide adds step, therefrom removes step or revise wherein step in this specification.Perhaps, one or more in the described step can executed in parallel, perhaps carries out in succession with the order different with described order.In general, flow chart just is used to refer to a kind of possible sequence of the basic operation that is used to realize function.

As the exemplary configuration of active coding checkout gear, shown the module that some are coupled among the figure.These modules can be implemented as hardware, software, firmware or their combination, utilize bus or any other holding wire or are coupled by any wireless connections, and can be used in their system, subsystem, parts or the subassembly.In addition, included parts are not limited to above-mentioned these modules in the device, and concrete configuration can be modified or change.

When realizing with software mode, element of the present invention is program or the code segment that is used to carry out required task.Program or code segment can be stored in the machine readable media, perhaps send at transmission medium or communication links by the data-signal that carries in the carrier wave." machine readable media " can comprise any medium that can store or transmit information.The example of machine readable media comprises electronic circuit, semiconductor memory devices, ROM, flash memory, can wipe ROM (EROM), floppy disk, CD-ROM, CD, hard disk, fiber medium, radio frequency (RF) link, or the like.Code segment can be downloaded via the computer network such as internet, Intranet etc.In general, function of the present invention can be realized by any means known in the art.

Claims (16)

1. one kind is used at the communication system down link link receiver, detects the method for active coding from the activation window of received signal, may further comprise the steps:

The matched filtering step is carried out matched filtering to obtain each filtering output of a plurality of code channels in the described activation window to described received signal;

Code channel power calculation step at each code channel, uses the filtering of this code channel to export the power that calculates this code channel;

The compensating factor calculation procedure at described each code channel, is used the spreading code and the channel impulse response of this code channel, calculates the compensating factor of this code channel;

The power back-off step at described each code channel, by with the power of described this code channel compensating factor divided by described this code channel, obtains the power after the compensation of this code channel; And

Active coding detects step, detects the code channel of activation according to the power after the compensation of described each code channel.

2. the method for claim 1, wherein said a plurality of code channels comprise a known first-selected code channel and one or more non-first-selected code channel, described first-selected code channel activates,

Described active coding detects step and further comprises following two steps:

The power ratio calculation procedure is calculated the ratio of the power after the compensation of power and described first-selected code channel after the compensation of each described non-first-selected code channel respectively; And

Code channel detects step, described power ratio is detected more than or equal to the spreading code of the code channel of a detection threshold be active coding, described power ratio is detected less than the spreading code of the code channel of described detection threshold be non-active coding.

3. the formula below the method for claim 1, the utilization of wherein said compensating factor calculation procedure calculates the compensating factor C of each channel:

C＝(b ^H×b) ²

Wherein, b is the convolution of the spreading code and the channel impulse response of this channel, and H represents conjugate transpose.

4. one kind is used at the communication system down link link receiver, detects the device of active coding from the activation window of received signal, comprising:

The matched filtering module is carried out matched filtering to obtain each filtering output of a plurality of code channels in the described activation window to described received signal;

The code channel power computation module at each code channel, uses the filtering of this code channel to export the power that calculates this code channel;

The compensating factor computing module at each code channel, uses the spreading code and the channel impulse response of this code channel, calculates the compensating factor of this code channel;

The power back-off module at each code channel, by with the power of this code channel compensating factor divided by this code channel, obtains the power after the compensation of this code channel; And

The active coding detection module detects the code channel of activation according to the power after the compensation of each code channel.

5. device as claimed in claim 4, wherein said a plurality of code channels comprise a known first-selected code channel and one or more non-first-selected code channel, and described first-selected code channel activates,

Described active coding detection module further comprises following two modules:

The power ratio computing module calculates the ratio of the power after the compensation of power and described first-selected code channel after the compensation of each described non-first-selected code channel respectively; And

The code channel detection module detects described power ratio and to be active coding more than or equal to the spreading code of the code channel of a detection threshold, described power ratio is detected less than the spreading code of the code channel of described detection threshold be non-active coding.

6. the formula below the device as claimed in claim 4, the utilization of wherein said compensating factor computing module calculates the compensating factor C of each channel:

C＝(b ^H×b) ²

Wherein, b is the convolution of the spreading code and the channel impulse response of this channel, and H represents conjugate transpose.

7. one kind is used at the communication system down link link receiver, detects the method for active coding from the activation window of received signal, may further comprise the steps:

The matched filtering step is carried out matched filtering to described received signal, to obtain each the filtering output vector of plural form of a plurality of code channels in the described activation window;

Vector rotation step, the element that the filtering output vector of each code channel is comprised carries out 45 degree phase places rotations, obtains postrotational output vector;

Soft information obtaining step extracts the real part and the imaginary part of the postrotational output vector of each code channel, and calculates their absolute value respectively, thereby obtains the soft information vector of the real number form of this code channel;

The median calculation step at each code channel, is calculated the intermediate value of each element that soft information vector comprises;

Soft erasing of information step for each code channel, will be changed to 0 than the little element of intermediate value that calculates at this code channel in the described median calculation step in the soft information vector of this code channel, the soft information vector after removing with acquisition;

Code channel power calculation step at each code channel, uses soft information vector after the removing of this code channel to calculate the power of this code channel; And

Active coding detects step, and the power of each code channel that calculates according to described code channel power calculation step detects the code channel of activation.

8. method as claimed in claim 7, wherein said a plurality of code channels comprise a known first-selected code channel and one or more non-first-selected code channel, and described first-selected code channel activates,

Described active coding detects step and further comprises following two steps:

The power ratio calculation procedure is calculated the power of each described non-first-selected code channel and the ratio of the power of described first-selected code channel respectively; And

Code channel detects step, described power ratio is detected more than or equal to the spreading code of the code channel of a detection threshold be active coding, described power ratio is detected less than the spreading code of the code channel of described detection threshold be non-active coding.

9. method as claimed in claim 7, the rotation of wherein said vector rotation step is undertaken by described filtering output vector be multiply by (1-j).

10. method as claimed in claim 7, wherein said code channel power calculation step is calculated the power p of each code channel as follows:

$p=\underset{n=1}{\overset{N}{\mathrm{\&Sigma;}}}{\left|a_n\right|}^2/N$

Wherein, a _nBe the nonzero component in the soft information vector after the removing of this code channel, N is the number of described nonzero component.

11. method as claimed in claim 8, wherein said detection threshold is 0.71.

12. one kind is used at the communication system down link link receiver, detects the device of active coding from the activation window of received signal, comprising:

The matched filtering module is carried out matched filtering to described received signal, to obtain each the filtering output vector of plural form of a plurality of code channels in the described activation window;

The vector rotary module, the element that the filtering output vector of each code channel is comprised carries out 45 degree phase places rotations, obtains postrotational output vector;

Soft information acquisition module extracts the real part and the imaginary part of the postrotational output vector of each code channel, and calculates their absolute value respectively, thereby obtains the soft information vector of the real number form of this code channel;

The median calculation module at each code channel, is calculated the intermediate value of each element that soft information vector comprises;

Soft erasing of information module for each code channel, will be changed to 0 than the little element of intermediate value that calculates at this code channel in the described median calculation step in the soft information vector of this code channel, the soft information vector after removing with acquisition;

The code channel power computation module at each code channel, uses soft information vector after the removing of this code channel to calculate the power of this code channel; And

The active coding detection module, the power of each code channel that calculates according to described code channel power calculation step detects the code channel of activation.

13. device as claimed in claim 12, wherein said a plurality of code channels comprise a known first-selected code channel and one or more non-first-selected code channel, described first-selected code channel activates,

Described active coding detection module further comprises following two modules:

The power ratio computing module calculates the power of each described non-first-selected code channel and the ratio of the power of described first-selected code channel respectively; And

The code channel detection module detects described power ratio and to be active coding more than or equal to the spreading code of the code channel of a detection threshold, described power ratio is detected less than the spreading code of the code channel of described detection threshold be non-active coding.

14. device as claimed in claim 12, the rotation that wherein said vectorial rotary module carries out is undertaken by described filtering output vector be multiply by (1-j).

15. device as claimed in claim 12, wherein said code channel power computation module is calculated code channel power p as follows:

$p=\underset{n=1}{\overset{N}{\mathrm{\&Sigma;}}}{\left|a_n\right|}^2/N$

Wherein, a _nBe the nonzero component in the soft information vector after the removing of this code channel, N is the number of described nonzero component.

16. device as claimed in claim 13, wherein said detection threshold is 0.71.

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