CN104092479B - Activation code detection method and device - Google Patents

Abstract

Disclose a kind of activation code detection method and device.A kind of in the descending link receiver of communication system, comprise the following steps from the method detecting active coding window that activates receiving signal: matched filtering step, carry out matched filtering to received signal to obtain activating the filtering of each output of the multiple code channels in window；Code channel power calculation step, for each code channel, uses the filtering output of this code channel to calculate the power of this code channel；Compensating factor calculation procedure, for each code channel, uses spreading code and the channel impulse response of this code channel, calculates the compensating factor of this code channel；Power back-off step, for each code channel, by by the power of this code channel compensating factor divided by this code channel, obtaining the power after the compensation of this code channel；And active coding detecting step, the code channel of activation is detected according to the power after the compensation of each code channel.

Description

Activation code detection method and device

The application be submit Patent Office of the People's Republic of China on July 16th, 2009, application number be 200910140071.0 the divisional application of patent application.

Technical field

This invention relates generally to TD SDMA (TD-SCDMA) wireless communication system, more particularly it relates to activation code detection method in TD-SCDMA receiver and device.

Background technology

TD-SCDMA is the 3G (Third Generation) Moblie air interface standard that Chinese Industrial Standardsization tissue is submitted to International Telecommunication Association.Oneself is received by International Telecommunication Association for it, and the part as CDMA-TDD pattern is written into international norm.Its key technology adopted includes: synchronization CDMA, smart antenna, joint-detection, software radio, baton handover etc..TD-SCDMA system adopts time division duplex (TDD) pattern, and uplink and downlink are to transmit at the different time-gap of same carrier frequency, separate with protection interval, have TDMA characteristic between upstream and downstream channel.In TD-SCDMA system, some users can send multiple different bursts at same time slot.Different spreading codes makes the signal can be separated at receiver place.According to required data rate, user can use some code channels and/or time slot.Due to the dependency between multipath effect and the user of mobile channel, there is intersymbol interference and multi-access inference in TD-SCDMA system.For this, TD-SCDMA receiver carries out on the basis of channel estimating at employing training sequence, make full use of the relevant prior information (spread spectrum code sequence and dependency etc. such as each user) of all users, get up to detect by the combined signal of all users, to reduce above-mentioned interference.

The channel impulse response obtained by channel estimating can be divided into the window corresponding to different training sequences.Receiver after carrying out active window confirmation just it is known which window be activate.Can having multiple code channel in one window, these code channels differ to establish a capital and are used, namely differ establish a capital be activate.The code channel of inactive window is generally considered to be nonactivated.And activate the code channel of window, still need to detection further to determine which code channel is really to activate.The purpose of active coding detection is exactly that detection activates the active coding in window to determine the code channel of activation.

The code channel method of salary distribution according to TD-SCDMA, there is a code channel necessarily used in each window, is called first-selected code channel.The first-selected matched filter output of code channel is simply just compared by traditional detection active coding mode with the matched filter output of other code channels.But, due to wireless environment pollution to received signal, the signal received usually contains noise, all the more so under severe conditions.And, before detection active coding, receiver to the received signal processes the power that can change each channel respectively.These factors result in the decline of active coding accuracy of detection.

Summary of the invention

Consider the problems referred to above, the invention discloses in the descending link receiver of communication system, activate, from what receive signal, the method and apparatus more precisely detecting active coding window.

According to an aspect of the present invention, provide a kind of in the descending link receiver of communication system, the method detecting active coding window is activated from what receive signal, comprise the following steps: matched filtering step, carry out matched filtering to received signal to obtain activating the filtering of each output of the multiple code channels in window；Code channel power calculation step, for each code channel, uses the filtering output of this code channel to calculate the power of this code channel；Compensating factor calculation procedure, for each code channel, uses spreading code and the channel impulse response of this code channel, calculates the compensating factor of this code channel；Power back-off step, for each code channel, by by the power of this code channel compensating factor divided by this code channel, obtaining the power after the compensation of this code channel；And active coding detecting step, the code channel of activation is detected according to the power after the compensation of each code channel.Wherein, the plurality of code channel includes oneself the first-selected code channel known and one or more non-preferred code channel, and first-selected code channel is to activate；Active coding detecting step farther includes power ratio calculation procedure and code channel detecting step, and described power ratio calculation procedure calculates the power ratio after the compensation of the power after the compensation of each described non-preferred code channel and described first-selected code channel respectively；Described code channel detecting step, the spreading code detection that described power ratio detects the code channel of threshold value be more than or equal to is active coding, described power ratio is detected as inactive code less than the spreading code of the code channel of described detection threshold value.

According to an aspect of the present invention, provide a kind of in the descending link receiver of communication system, the method detecting active coding window is activated from what receive signal, comprise the following steps: matched filtering step, carry out matched filtering to received signal, to obtain activating the filtering output vector of the plural form of each of the multiple code channels in window；Vector rotation step, carries out the element that the filtering output vector of each code channel comprises 45 degree of phase places and rotates, obtain postrotational output vector；Soft Inform ation obtaining step, extracts real part and the imaginary part of the postrotational output vector of each code channel, and calculates their absolute value respectively, thus obtaining the Soft Inform ation vector of the real number form of this code channel；Median calculation step, for each code channel, calculates the intermediate value of each element that Soft Inform ation vector comprises；Soft Inform ation removes step, for each code channel, element little for the intermediate value calculated for this code channel than in median calculation step in the Soft Inform ation vector of this code channel is set to 0, vectorial to obtain the Soft Inform ation after removing；Code channel power calculation step, for each code channel, uses the Soft Inform ation vector after the removing of this code channel to calculate the power of this code channel；And active coding detecting step, the power of each code channel calculated according to code channel power calculation step detects the code channel of activation.Wherein, the plurality of code channel includes a known first-selected code channel and one or more non-preferred code channel, and first-selected code channel is to activate；Active coding detecting step farther includes power ratio calculation procedure and code channel detecting step, described power ratio calculation procedure calculates the power of each described non-preferred code channel and the power ratio of described first-selected code channel respectively, it is active coding that described power ratio is closed the spreading code detection of the code channel of value by described code channel detecting step be more than or equal to a detection, described power ratio is detected as inactive code less than the spreading code of the code channel of described detection thresholds.

According to a further aspect of the invention, a kind of in the descending link receiver of communication system, the device detecting active coding window is activated from what receive signal, including: matched filtering module, carry out matched filtering to received signal to obtain activating the filtering of each output of the multiple code channels in window；Code channel power computation module, for each code channel, uses the filtering output of this code channel to calculate the power of this code channel；Compensating factor computing module, for each code channel, uses spreading code and the channel impulse response of this code channel, calculates the compensating factor of this code channel；Power compensation module, for each code channel, by by the power of this code channel compensating factor divided by this code channel, obtaining the power after the compensation of this code channel；And active coding detection module, the code channel of activation is detected according to the power after the compensation of each code channel.Wherein, the plurality of code channel includes oneself the first-selected code channel known and one or more non-preferred code channel, and first-selected code channel is to activate；Active coding detection module farther includes power ratio computing module and code channel detection module, and described power ratio computing module calculates the power ratio after the compensation of the power after the compensation of each described non-preferred code channel and described first-selected code channel respectively；Described code channel detection module, the spreading code detection that described power ratio detects the code channel of threshold value be more than or equal to is active coding, described power ratio is detected as inactive code less than the spreading code of the code channel of described detection threshold value.

According to a further aspect of the invention, provide a kind of in the descending link receiver of communication system, the method detecting active coding window is activated from what receive signal, including with lower module: matched filtering module, carry out matched filtering to received signal, to obtain activating the filtering output vector of the plural form of each of the multiple code channels in window；Vector rotation module, carries out the element that the filtering output vector of each code channel comprises 45 degree of phase places and rotates, obtain postrotational output vector；Soft Inform ation acquisition module, extracts real part and the imaginary part of the postrotational output vector of each code channel, and calculates their absolute value respectively, thus obtaining the Soft Inform ation vector of the real number form of this code channel；Median calculation module, for each code channel, calculates the intermediate value of each element that Soft Inform ation vector comprises；Soft Inform ation removes module, for each code channel, element little for the intermediate value calculated for this code channel than in median calculation module in the Soft Inform ation vector of this code channel is set to 0, vectorial to obtain the Soft Inform ation after removing；Code channel power computation module, for each code channel, uses the Soft Inform ation vector after the removing of this code channel to calculate the power of this code channel；And active coding detection module, the power of each code channel calculated according to code channel power computation module detects the code channel of activation.Wherein, the plurality of code channel includes a known first-selected code channel and one or more non-preferred code channel, and first-selected code channel is to activate；Active coding detection module farther includes power ratio computing module and code channel detection module, described power ratio computing module calculates the power of each described non-preferred code channel and the power ratio of described first-selected code channel respectively, it is active coding that described power ratio is detected by described code channel detection module be more than or equal to the spreading code of the code channel of a detection door screen value, and the spreading code detection of the code channel that described power ratio is closed value less than described detection is inactive code.

In sum, the present invention is when carrying out active coding detection, take into account by being processed, by receiver, the power accumulated before being detected by active coding, adjust the power before judgement, and/or before judgement, reduce noise, active coding detection is carried out, thus achieving more accurate testing result with higher precision.

Accompanying drawing explanation

Accompanying drawing by being merely to illustrate property purpose below reference, it is possible to more fully understand the present invention, wherein:

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

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

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

Fig. 4 is the block diagram illustrating active coding detecting device according to an embodiment of the invention；

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

Fig. 6 is the block diagram illustrating active coding detecting device in accordance with another embodiment of the present invention；And

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

Detailed description of the invention

Feature and the exemplary embodiment of various aspects of the invention are described more fully below.In the following detailed description, exemplified with many details, in order to those skilled in the art can be apparent from the present invention.It will, however, be evident that be, the enforcement of the present invention can in some details in not needing these details.The description of specific embodiment is only used as example and unrestricted provides.The various amendments of example described herein and combination will be apparent to persons skilled in the art, and the General Principle defined here may be used in other examples and application under the premise without departing from the spirit and scope of the present invention.Therefore, it is not intended that limit the present invention in the example describing and illustrating, but give its widest range meeting herein disclosed principles and feature.For not fuzzy understanding of the description, it does not have be shown specifically known structure and technology.

Fig. 1 illustrates the brief block diagram of TD-SCDMA wireless communication system.As it is shown in figure 1, this wireless communication system mainly includes core net 102, wireless access network 104 and subscriber equipment 106.Core net 102 mainly process the audio call in wireless communication system, data cube computation and exchange, customer position information management, network characteristic and Service control, signaling and user profile transmission mechanism and with the connection of other network and route etc..Wireless access network 104 provides the connection of subscriber equipment and core net, and the management of responsible Radio Resource and allotment, including base station and radio network controller two category node.Subscriber equipment 106 can be such as mobile phone, personal digital assistant (PDA) or other there is the Portable data processing equipment of the function communicated in TD-SCDMA wireless communication system.

Fig. 2 illustrates the brief block diagram of the concrete structure of subscriber equipment shown in Fig. 1.As shown in Figure 2, this subscriber equipment specifically includes that 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, AN side SNR measurement module 216, demapping (demapping) module 218 and decoder module 220.The analogue signal received is unloaded ripple and analog-to-digital conversion and is processed by radio-frequency module 202, is input to subordinate so that the analogue signal received is transformed to baseband digital signal.Forming filter 204, namely baseband digital signal is carried out pulse shaping by root raised cosine filter (SRRC).Channel estimation module 206 carries out the channel estimating of multiple community for the midamble code sequence in the signal after pulse shaping.Multipath tracking module 208 utilizes channel estimation results, it is determined that optimum sampling point, and the multipath window position carrying out each community is followed the tracks of.Activate detection module 210 to be used for carrying out window activation detection and code-division activated detection.The data of the joint-detection module 212 each code channel to being aliasing in together carry out certain calculating, obtain the transmission symbol on each code channel.Frequency deviation estimating modules 214 utilizes joint detection results to estimate frequency shift (FS).AN side SNR measurement module 216 utilizes joint detection results to carry out amplitude and noise ratio (ANR) and signal to noise ratio (SNR) is measured.The symbol that joint-detection module exports is converted to soft bit and delivers to decoder module by demapping (demapping) module 218.The soft bit result exported by De-mapping module is decoded by decoder module 220, obtains information bit.

The disclosure is mainly for the detection activating the active coding performed in detection module 210.Should be noted that, although being presented above the configuration example of TD-SCDMA wireless communication system as depicted in figs. 1 and 2 and subscriber equipment, it can be recognized that, communication system and the subscriber equipment that can use the present invention wherein are not limited to this concrete example, but may adapt to need various systems and the equipment of detection active coding.

Fig. 3 illustrates the schematic diagram of the structure 300 of channel matrix T in TD-SCDMA data reception signal model, and wherein matrix-block V represents the fundamental matrix block for constructing channel matrix T.Below with reference to Fig. 3, the generation process of channel matrix T is carried out mathematical description.

[channel matrix T]

Make h_kRepresent the channel impulse response (CIR) relevant to kth code channel.

h_k=[h_k ⁽¹⁾h_k ⁽²⁾…h_k ^(w)], k=1,2 ..., K (1)

Wherein, K is the code channel number being detected as in the window of activation after active window confirmation, and W is the length of channel impulse response.

If with channel impulse response h_kRelevant spreading code vector c_kRepresent, then c_kQ × 1 dimensional vector can being expressed as with following formula, Q is spreading factor:

c_k=w_k·OVSF_k·v_k, k=1,2 ..., K (2)

Wherein OVSF_kRepresent the channel code vector of Q × 1 dimension, w_kRepresent the multiplier vector relevant with channel code, v_kRepresenting the scrambler vector of Q × 1 dimension, wherein symbol represents dot product, namely by element multiplication.

By channel impulse response h_kWith spreading code c_kUsing Convolution become vector b_k:

$b_k=c_k\⊗h_k,k=\mathrm{1,2},......,K---\left(3\right)$

Then b_kFor (Q+W-1) × 1 dimension column vector, represents equivalence merging channel impulse response.

Note, here w_k、OVSF_kAnd v_kIt is according to channel impulse response h_kBelonging to code channel and what community was arranged in a communications system in advance.

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

V=[b₁, b₂..., b_k](4)

Each of which row are for a code channel.Noting, code channel may be from different districts.

[output of matched filter]

Receive the column vector r of (NQ+W-1) × 1 dimension that signal can be expressed as:

R=Td+n (5)

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

Receive signal r and be subsequently input in the wave filter matched with channel (as known to the skilled person, this wave filter is also referred to as matched filter), this process can be multiplied by received signal vector r and obtains the output vector x of matched filter with the transposition of gripping altogether of channel matrix T and represent:

X=T^Hr(6)

Convolution (5), order receives signal r by above-mentioned matched filter, is equivalent to make transmission signal d be multiplied by matrix T^HT.Due to nearly orthogonal between every string of matrix-block V, bigger value is only present in matrix T^HOn the diagonal of T.

Which code channel being intended to detect in the output vector x of matched filter as above of active coding detection has is activate.Agreement according to TD-SCDMA specifies, a first-selected code channel activating window is considered as always what activate.Whether other code channels of this activation window are that what to activate is determine by being made comparisons by the matched filter output of the matched filter output of this code channel with first-selection code channel.Specifically, when the matched filter output of a code channel and the ratio of the matched filter output of first-selected code channel are more than a certain threshold value, this code channel is considered as what activate；Otherwise, this code channel is considered as nonactivated.Wherein, being the empirical value that emulation obtains as the threshold value of criterion, those skilled in the art can adjust flexibly according to the demodulation performance (such as block error rate BLER, error rate BER etc.) after using this parameter or according to the detection performance of active coding (such as the detection probability of active coding and false-alarm probability etc.).

Fig. 4 is the block diagram illustrating active coding detecting device according to an embodiment of the invention.This device compensates based on receiver power and carries out active coding detection.As shown in Figure 4, active coding detecting device 400 mainly includes with lower module according to an embodiment of the invention: matched filtering module 401, carries out matched filtering to received signal to obtain activating the filtering of each output of the multiple code channels in window；Code channel power computation module 402, for each code channel, uses the filtering output of this code channel to calculate the power of this code channel；Compensating factor computing module 403, for each code channel, uses spreading code and the channel impulse response of this code channel, calculates the compensating factor of this code channel；Power compensation module 404, for each code channel, by by the power of this code channel compensating factor divided by this code channel, obtaining the power after the compensation of this code channel；And active coding detection module 405, the code channel of activation is detected according to the power after the compensation of each code channel.

Fig. 5 is the flow chart illustrating activation code detection method 500 according to an embodiment of the invention, and the method compensates based on receiver power and carries out active coding detection, and its each step comprised can be completed by the corresponding module of active coding detecting device 400 respectively.Each step that activation code detection method 500 comprise is described in detail below:

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

As it has been described above, this step is equivalent to grip the received signal vector r after transposition is multiplied by active window confirmation altogether with channel matrix T, obtain the filtering output vector x of each code channel_k(1≤k≤K), wherein K is the code channel number being detected as in the window of activation after active window confirmation.

[step S502], for each code channel, uses the filtering output of this code channel to calculate the power of this code channel.

To the filtering output vector x obtained in step S501_kEach component squared and, then divided by vector dimension N, thus obtaining the output p ' of the matched filter of kth code channel_k, it is possible to 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}For filtering output vector x_kThe n-th component.

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

Firstly, for each code channel, by by the spreading code b of this code channel_kWith channel impulse response h_kDoing convolution, the equivalence calculating this code channel merges channel impulse response b_k:

$b_k=c_k\&CircleTimes;h_k$

Then, by calculating equivalence merging channel impulse response b_kThe quadratic sum of modulus value, calculate the compensating factor C of this code channel_k:

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

Wherein, subscript H represents and grips transposition altogether.

[step S504] for each code channel, by by the power of this code channel compensating factor divided by this code channel, obtaining the power after the compensation of this code channel.

For each code channel, the output p ' of matched filter that will obtain in step S502_kDivided by the compensating factor C obtained in step S503_k, obtain the power p after the compensation of this code channel_k, thereby compensate for being processed caused power excursion by receiver.This step can be expressed as:

p_k=p '_k/C_k

[step S505] detects the code channel of activation according to the power after the compensation of each code channel.Code selection is designated as 1 under road, for non-preferred code channel k, calculates its power p_kWith first-selected code channel power p₁Ratio r:

R=p_k/p₁

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

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

Wherein, activenag represents activation marker, α₁It is the threshold value for activated code channel detection, it is possible to obtained by emulation according to the standard of such as detection probability, false-alarm probability etc.

Fig. 6 is the block diagram illustrating active coding detecting device in accordance with another embodiment of the present invention.This device carries out active coding detection based on noise reduction.As shown in Figure 6, active coding detecting device 600 mainly includes with lower module according to an embodiment of the invention: matched filtering module 601, described reception signal is carried out matched filtering, to obtain the filtering output vector of the plural form of each of the multiple code channels in described activation window；Vector rotation module 602, carries out the element that the filtering output vector of each code channel comprises 45 degree of phase places and rotates, obtain postrotational output vector；Soft Inform ation acquisition module 603, extracts real part and the imaginary part of the postrotational output vector of each code channel, and calculates their absolute value respectively, thus obtaining the Soft Inform ation vector of the real number form of this code channel；Median calculation module 604, for each code channel, calculates the intermediate value of each element that Soft Inform ation vector comprises；Soft Inform ation removes module 605, for each code channel, element little for the intermediate value calculated for this code channel than in described median calculation step in the Soft Inform ation vector of this code channel is set to 0, vectorial to obtain the Soft Inform ation after removing；Code channel power computation module 606, for each code channel, uses the Soft Inform ation 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 calculated according to described code channel power calculation step detects the code channel of activation.

Fig. 7 is the flow chart illustrating activation code detection method 700 in accordance with another embodiment of the present invention, and the method carries out active coding detection based on noise reduction, and its each step comprised can be completed by the corresponding module of active coding detecting device 600 respectively.Each step that activation code detection method 700 comprise is described in detail below:

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

As it has been described above, this step is equivalent to grip the received signal vector r after transposition is multiplied by active window confirmation altogether with channel matrix T, obtain the filtering output vector x of each code channel_k(1≤k≤K), wherein K is the code channel number being detected as in the window of activation after active window confirmation.

[step S702] is by the filtering output vector x of each code channel_kThe element comprised carries out 45 degree of phase places and rotates, and obtains postrotational output vector v_k。

Will filtering output vector x_kIn each element be multiplied by (1-j) to rotate 45 degree, it is possible to 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, thus obtaining the Soft Inform ation 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 [] represents the content in [] is launched into vector, and Re [] represents treating excess syndrome portion, and Im [] expression takes imaginary part, and abs{} represents and takes absolute value.

[step S704], for each code channel, calculates the Soft Inform ation vector a of this code channel_kIntermediate value med (a of each element comprised_k)。

By Soft Inform ation vector a_kEach component comprised arranges from big to small, due to Soft Inform ation vector a_kComprise even number component, therefore intermediate value med (a_k) equal to the meansigma methods of two centrally located components.

[step S705] for each code channel, by the Soft Inform ation vector a of this code channel_kMiddle than the intermediate value med (a calculated for this code channel in described median calculation step_k) little element is set to O, to obtain the Soft Inform ation vector a ' after removing_k。

This step is to remove the noise of Soft Inform ation in code channel, it is possible to 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}For vector a '_kNth elements, 2N is a '_kDimension.

[step S706], for each code channel, uses the Soft Inform ation vector a ' after the removing of this code channel_kCalculate the power p of this code channel_k。

To the Soft Inform ation vector a ' after the removing obtained in step S706_kEach component squared and, then divided by total number of the component not being zeroed out in step S706, thus obtaining the power a ' of this code channel_k.This step can represent 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}For vector a '_kThe n-th component, N_restFor the component that is not zeroed out in step S706, total number.

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

It is designated as 1 under first-selected code channel, for non-preferred code channel k, calculates its power p_kWith first-selected code channel power p₁Ratio:

R=p_k/p₁

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

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

Wherein, activeflag represents activation marker, α₂It is the threshold value for activated code channel detection, it is possible to being obtained by emulation according to the standard of such as detection probability, false-alarm probability etc, its representative value is 0.71.

Above-mentioned activation code detection method 500 and activation code detection method 700, also in combinations with getting up to use, obtain the activation code detection method compensated based on noise reduction and receiver power, to obtain higher accuracy of detection.

Oneself is through being described with reference to the drawings some the concrete examples according to the present invention above.But, the present invention does not really want the restriction being subject to any concrete configuration and process described in above-described embodiment.Within the scope of the spirit of the present invention, those skilled in the art are able to recognize that various replacements, change or the amendment of above-mentioned configuration, algorithm, operation and process.

The various method steps above in association with accompanying drawing description can be performed as required with hardware or software.Noting, without departing from the scope of the invention, the flow chart that can provide in this specification adds step, therefrom removal step or revises step therein.Or, in described step one or more can executed in parallel, or in succession to perform with described order different.In general, flow chart is only used to indicate a kind of possible sequence of the basic operation realizing function.

As the exemplary configuration of active coding detecting device, figure has been illustrated with some modules being coupled.These modules can be implemented as hardware, software, firmware or their combination, utilizes bus or any other holding wire or is coupled by any wireless connections, and being usable in their system, subsystem, parts or subassembly.It addition, parts included in device are not limited to these modules above-mentioned, concrete configuration can be modified or varied.

When realizing with software mode, the element of the present invention is used to perform program or the code segment of required task.Program or code segment can be stored in machine readable media, or sent at transmission medium or communication links by the data signal carried in carrier wave." machine readable media " may be configured to storage or any medium of transmission information.The example of machine readable media includes electronic circuit, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disk, CD-ROM, CD, hard disk, fiber medium, radio frequency (RF) link, etc..Code segment can be downloaded via the computer network of such as the Internet, Intranet etc..In general, the function of the present invention can be realized by any means known in the art.

Claims (10)

1. one kind is used in the descending link receiver of communication system, activates, from what receive signal, the method detecting active coding window, comprises the following steps:

Matched filtering step, carries out matched filtering to described reception signal, to obtain the filtering output vector of the plural form of each of the multiple code channels in described activation window；

Vector rotation step, carries out the element that the filtering output vector of each code channel comprises 45 degree of phase places and rotates, obtain postrotational output vector；

Soft Inform ation obtaining step, extracts real part and the imaginary part of the postrotational output vector of each code channel, and calculates their absolute value respectively, thus obtaining the Soft Inform ation vector of the real number form of this code channel；

Median calculation step, for each code channel, calculates the intermediate value of each element that Soft Inform ation vector comprises；

Soft Inform ation removes step, for each code channel, element little for the intermediate value calculated for this code channel than in described median calculation step in the Soft Inform ation vector of this code channel is set to 0, vectorial to obtain the Soft Inform ation after removing；

Code channel power calculation step, for each code channel, uses the Soft Inform ation vector after the removing of this code channel to calculate the power of this code channel；And

Active coding detecting step, the power of each code channel calculated according to described code channel power calculation step detects the code channel of activation.

2. the method for claim 1, wherein said multiple code channels include oneself the first-selected code channel known and one or more non-preferred code channel, and described first-selected code channel is to activate,

Described active coding detecting step farther includes following two steps:

Power ratio calculation procedure, calculates the power of each described non-preferred code channel and the power ratio of described first-selected code channel respectively；And

Code channel detecting step, the spreading code detection that described power ratio detects the code channel of threshold value be more than or equal to is active coding, described power ratio is detected as inactive code less than the spreading code of the code channel of described detection threshold value.

3. the method for claim 1, the rotation of wherein said Vector rotation step is undertaken by described filtering output vector is multiplied by (l j).

4. the method for claim 1, wherein said code channel power calculation step is calculated as follows the power p of each code channel:

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

Wherein, a_nFor the nonzero component in the Soft Inform ation vector after the removing of this code channel, N is the number of described nonzero component.

5. method as claimed in claim 2, wherein said detection threshold value is 0.71.

6. one kind is used in the descending link receiver of communication system, activates, from what receive signal, the device detecting active coding window, including:

Matched filtering module, carries out matched filtering to described reception signal, to obtain the filtering output vector of the plural form of each of the multiple code channels in described activation window；

Vector rotation module, carries out the element that the filtering output vector of each code channel comprises 45 degree of phase places and rotates, obtain postrotational output vector；

Soft Inform ation acquisition module, extracts real part and the imaginary part of the postrotational output vector of each code channel, and calculates their absolute value respectively, thus obtaining the Soft Inform ation vector of the real number form of this code channel；

Median calculation module, for each code channel, calculates the intermediate value of each element that Soft Inform ation vector comprises；

Soft Inform ation removes module, for each code channel, element little for the intermediate value calculated for this code channel than in described median calculation step in the Soft Inform ation vector of this code channel is set to 0, vectorial to obtain the Soft Inform ation after removing；

Code channel power computation module, for each code channel, uses the Soft Inform ation vector after the removing of this code channel to calculate the power of this code channel；And

Active coding detection module, the power of each code channel calculated according to described code channel power calculation step detects the code channel of activation.

7. device as claimed in claim 6, wherein said multiple code channels include oneself the first-selected code channel known and one or more non-preferred code channel, and described first-selected code channel is to activate,

Described active coding detection module farther includes following two modules；

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

Code channel detection module, the spreading code detection that described power ratio detects the code channel of threshold value be more than or equal to is active coding, described power ratio is detected as inactive code less than the spreading code of the code channel of described detection threshold value.

8. device as claimed in claim 6, the rotation that wherein said Vector rotation module carries out is

By described filtering output vector being multiplied by, (1-j) carry out.

9. device as claimed in claim 6, wherein said code channel power computation module is calculated as follows code channel power p:

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

Wherein, a_nFor the nonzero component in the Soft Inform ation vector after the removing of this code channel, N is the number of described nonzero component.

10. device as claimed in claim 7, wherein said detection threshold value is 0.710.