CN1464658A - Prefix detector for WCDMA - Google Patents
Prefix detector for WCDMA Download PDFInfo
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- CN1464658A CN1464658A CN 02112105 CN02112105A CN1464658A CN 1464658 A CN1464658 A CN 1464658A CN 02112105 CN02112105 CN 02112105 CN 02112105 A CN02112105 A CN 02112105A CN 1464658 A CN1464658 A CN 1464658A
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- sliding window
- prefix
- window correlator
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Abstract
The invention discloses a broad band code division multiple access (CDMA) prefix detector characterized by that, a timing device is added to the detector, the timing device calculates the time from the starting time of the down channel sending frame according to the time relationship between the user end up and down channel and the size of the subzone and sends control signal to the sliding window correlator. Further, the sliding window correlator performs sliding window correlating to intervening code and the signal of the phase removed rotation factor according to the control information of the clock. In the time when there may be prefix arriving, the sliding window register shifts and correlates the input signal and the intervening code, in the time apart from the said period, there is no signal output. Therefore the detector reduces substantially the unnecessary operations, the negative influence caused by the operating result is also diminished, the false alarm rate is lowered.
Description
Technical field
The present invention relates to digital wireless communication, specifically refer to a kind of Wideband Code Division Multiple Access (WCDMA) prefix detector, this detector can be discerned useful signal in common radio channel, promptly the access of the up common radio channel of Wideband Code Division Multiple Access (WCDMA) is discerned.
Background technology
In Wideband Code Division Multiple Access (WCDMA), up Random Access Channel and CPCH all are to send prefix earlier to the UTRAN end, then the further action of response message decision that provides according to the UTRAN end.The present invention is the receiving system of prefix.
The generation of the prefix part of up access channel is shown below:
pre(n)＝Scrm(n)*Sig(n)*exp(j*(PI/4+n*PI/2))，n＝0，...，4095。
Wherein signature sequence Sig (n) is that 16 Hadamard code sign indicating number sequence repeats 256 times and forms by a length.
The transmission of each bar channel prefix, is exported after the scrambling of process spread spectrum coding at the given selected signature of concentrating then by travelling carriage.The UTRAN end does not know that travelling carriage uses that signature emission, therefore, check the signature that all are available, and whether provide each signature has prefix to arrive.
Because in Wideband Code Division Multiple Access (WCDMA), up channel does not provide the synchronizing information of UTRAN end, promptly UTRAN does not know when up channel arrives, and therefore, conventional prefix detector is by constantly search, and whether constantly sliding window is correlated with to differentiate has prefix to arrive.Conventional prefix detector as shown in Figure 1.
Scrambling generator 2 produces Scrm (n) among Fig. 1, promptly produces+1 ,-1 scrambler signal, delivers to sliding window correlator 3 together and carries out relevantly with the received signal after removing phase rotation coefficient exp (j* (PI/4+n*PI/2)), and correlation length is a N chip.Sliding window correlator carries out once sliding window and is correlated with when each chip arrives.Accumulator 4 is delivered in the output of sliding window correlator 3, adds up every 16 chips, obtains the signal behind the descrambling and de-spreading.The output of accumulator 4 is delivered to Hadamard code converter unit 5 and is carried out quick Hadamard code conversion, once obtains and the real part of each signature, the Hadamard code conversion correlation of imaginary part.At last, correlation is imported into the judgement whether decision device 6 has the prefix arrival of related signature.
The shortcoming of this conventional prefix detector is tangible.In agreement, provided the time relationship between up access channel of user side and down channel.Because the size of sub-district is limited, in fact prefix only might arrive the UTRAN end in limited time range.Traditional detector has been wasted a large amount of operands, and can increase the alert rate of mistake of reception.
Summary of the invention
Shortcoming at the prefix detector of above-mentioned routine exists the purpose of this invention is to provide a kind of Wideband Code Division Multiple Access (WCDMA) prefix detector, and this detector can reduce operand and improve to receive precision greatly.
To achieve these goals, the present invention adopts following technical scheme: this Wideband Code Division Multiple Access (WCDMA) prefix detector comprise successively connect remove twiddle factor unit, scrambling generator, sliding window correlator, accumulator, Hadamard code converter unit, decision device,
Wherein, go to the twiddle factor unit that input signal and twiddle factor are carried out conjugate complex and take advantage of, remove the influence that phase change is brought in transmitting;
Scrambling generator produces+1 ,-1 scrambler signal, and removes phase rotation coefficient, sends the preceding N position Scrm (n) of uplink scrambling code sequence, gives sliding window correlator and is correlated with, and correlation length is a N chip;
Sliding window correlator carries out once sliding window when each chip arrives relevant and output to accumulator;
Accumulator in the ordered sequence of sliding window correlator output from the 1st, 2, ... 16 data begin to add up every 16 chips, making the relevant real part imaginary part of each displacement of sliding window correlator respectively obtain 16 signals behind the descrambling and de-spreading is input in the Hadamard code converter unit, after having calculated once sliding window correlator shifted correlation result, the accumulator zero clearing;
The Hadamard code converter unit carries out quick 16 Hadamard code conversion to data real part, imaginary part that the accumulator input comes respectively, once obtains the real part of each signature of this correlations, the Hadamard code conversion correlation of imaginary part;
The judgement whether decision device has the prefix of corresponding signature to arrive.
It is to be noted, prefix detector of the present invention further comprises timer, timer is sent the time started of frame and starts the clock according to the time relationship and the cell size of the up-downgoing channel of user side by down channel, send control signal to sliding window correlator.
Described timer begins back T1 after the time according to the user side up-downgoing channel timing relationship of agreement regulation at descending AICH Acquisition Indication Channel, and timer sends the control signal open command to sliding window correlator, makes sliding window correlator begin sliding window and is correlated with; After all had the time span T2 that prefix arrives, timer sent the control signal out code to sliding window correlator, sliding window correlator only was shifted and uncorrelated, did not have signal output.
Described sliding window correlator is according to the control information of timer, and it is relevant that the signal of scrambler and removal phase rotation coefficient is slided window, in the time that has prefix arrival, and the register shift of sliding window correlator, and input signal and scrambler signal correction; In time outside this scope, the register shift of sliding window correlator, but that sliding window correlator is not done is relevant, does not have signal output.
Described sliding window correlator is relevant respectively the real part imaginary part of scrambler and input signal, and correlated results is divided into two-way input accumulator.
In described decision device, the Hadamard code conversion correlation square summation the real part of each signature, imaginary part compares with judgement threshold, if greater than judgement threshold, then thinking has the prefix of a corresponding signature to arrive on this position; Otherwise thinking does not have the corresponding prefix of this signature to arrive on the relevant position.
Because the present invention has adopted above-mentioned technical scheme, on the basis of the detector of routine, increased timer, timer is according to the time relationship and the cell size of the up-downgoing channel of user side, send the time started of frame by down channel and start the clock, send control signal to sliding window correlator; In addition, sliding window correlator is according to the control information of timer, and it is relevant that the signal of scrambler and removal phase rotation coefficient is slided window, in the time that has prefix arrival, and the register shift of sliding window correlator, and input signal and scrambler signal correction; In time outside this scope, the register shift of sliding window correlator, but that sliding window correlator is not done is relevant, does not have signal output.Therefore, this detector has significantly reduced useless computing, and has reduced because the negative effect that the result of these computings brings is warned rate but also reduced the mistake that receives.
Description of drawings
Fig. 1 is the prefix detector principle block diagram of the Wideband Code Division Multiple Access (WCDMA) of routine.
Fig. 2 is the prefix detector principle block diagram of Wideband Code Division Multiple Access (WCDMA) of the present invention.
Embodiment
See also shown in Figure 2, Wideband Code Division Multiple Access (WCDMA) prefix detector of the present invention comprise successively connect remove twiddle factor unit 1, scrambling generator 2, sliding window correlator 3, accumulator 4, Hadamard code converter unit 5, decision device 6,
In Fig. 2, the signal that receives through removing twiddle factor unit 1, is removed phase rotation coefficient earlier, makes each symbol signal that receives have identical phase place in relevant range.
Wherein, go to twiddle factor unit 1 input signal and twiddle factor exp (j* (PI/4+n*PI/2)), (n=0,1,2 ...) carry out conjugate complex and take advantage of, remove the influence that phase change is brought in transmitting; Exp (j* (PI/4+n*PI/2)), (n=0,1,2 ...) carry out conjugate complex and take advantage of, remove the influence that phase change is brought in transmitting.
Conjugate complex is taken advantage of the influence that can not eliminate phase rotation coefficient fully, but can become a definite value to the influence of phase rotation coefficient.
Scrambling generator 2 produces+1 ,-1 scrambler signal, and removes phase rotation coefficient, and (0＜n＜N+1) give sliding window correlator 3 to be correlated with, correlation length is a N chip to send the preceding N position Scrm (n) of uplink scrambling code sequence.
Sliding window correlator 3 carries out once sliding window when each chip arrives relevant and output to accumulator 4.
Accumulator 4 in the ordered sequence of sliding window correlator 3 outputs from the 1st, 2, ... 16 data begin to add up every 16 chips, make the relevant real part imaginary part of each displacement of sliding window correlator 3 respectively obtain 16 signals behind the descrambling and de-spreading and are input in the Hadamard code converter unit.After having calculated once sliding window correlator 3 shifted correlation result, the accumulator zero clearing.
Hadamard code converter unit 5 carries out quick 16 Hadamard code conversion to data real part, imaginary part that the accumulator input comes respectively, once obtains the real part of each signature of this correlations, the Hadamard code conversion correlation of imaginary part.
The judgement whether decision device 6 has the prefix of corresponding signature to arrive.
It is to be noted, prefix detector of the present invention further comprises timer 7, timer 7 is sent the time started of frame and starts the clock according to the time relationship and the cell size of the up-downgoing channel of user side by down channel, send control signal to sliding window correlator 3.
Timer 7 begins back T1 after the time according to the user side up-downgoing channel timing relationship of agreement regulation at descending AICH Acquisition Indication Channel, and timer 7 sends the control signal open command to sliding window correlator 3, makes sliding window correlator 3 begin sliding window and is correlated with; After all had the time span T2 that prefix arrives, timer 7 sent the control signal out code to sliding window correlator 3, made 3 displacements of sliding window correlator and uncorrelated, did not have signal output.
Described sliding window correlator 3 is according to the control information of timer 7, it is relevant that scrambler and the signal of removing phase rotation coefficient are slided window, in the time that has prefix arrival, the register shift of sliding window correlator 3, and input signal and scrambler signal correction, in the time outside this scope, register 3 displacements of sliding window correlator, but it is relevant that sliding window correlator 3 is not done, and do not have signal output.
Described sliding window correlator 3 is relevant respectively the real part imaginary part of scrambler and input signal, and correlated results is divided into two-way input accumulator 4.
In described decision device 6, the Hadamard code conversion correlation square summation the real part of each signature, imaginary part compares with judgement threshold, if greater than judgement threshold, then thinking has the prefix of a corresponding signature to arrive on this position; Otherwise thinking does not have the corresponding prefix of this signature to arrive on the relevant position.
Claims (5)
1, a kind of Wideband Code Division Multiple Access (WCDMA) prefix detector, this prefix detector comprise successively connect remove twiddle factor unit, scrambling generator, sliding window correlator, accumulator, Hadamard code converter unit, decision device,
Wherein, go to the twiddle factor unit that input signal and twiddle factor are carried out conjugate complex and take advantage of, remove the influence that phase change is brought in transmitting;
Scrambling generator produces+1 ,-1 scrambler signal, and removes phase rotation coefficient, sends the preceding N position Scrm (n) of uplink scrambling code sequence, gives sliding window correlator and is correlated with, and correlation length is a N chip;
Sliding window correlator carries out once sliding window when each chip arrives relevant and output to accumulator;
Accumulator in the ordered sequence of sliding window correlator output from the 1st, 2, ... 16 data begin to add up every 16 chips, making the relevant real part imaginary part of each displacement of sliding window correlator respectively obtain 16 signals behind the descrambling and de-spreading is input in the Hadamard code converter unit, after having calculated once sliding window correlator shifted correlation result, the accumulator zero clearing;
The Hadamard code converter unit carries out quick 16 Hadamard code conversion to data real part, imaginary part that the accumulator input comes respectively, once obtains the real part of each signature of this correlations, the Hadamard code conversion correlation of imaginary part;
The judgement whether decision device has the prefix of corresponding signature to arrive.
It is characterized in that:
Described prefix detector further comprises timer, and timer is sent the time started of frame and starts the clock according to the time relationship and the cell size of the up-downgoing channel of user side by down channel, sends control signal to sliding window correlator.
2, Wideband Code Division Multiple Access (WCDMA) prefix detector as claimed in claim 1, it is characterized in that: described timer is according to the user side up-downgoing channel timing relationship of agreement regulation, begin back T1 after the time at descending AICH Acquisition Indication Channel, timer sends the control signal open command to sliding window correlator, makes sliding window correlator begin sliding window and is correlated with; After all had the time span T2 that prefix arrives, timer sent the control signal out code to sliding window correlator, sliding window correlator only was shifted and uncorrelated, did not have signal output.
3 Wideband Code Division Multiple Access (WCDMA) prefix detectors as claimed in claim 1, it is characterized in that: described sliding window correlator is according to the control information of timer, it is relevant that scrambler and the signal of removing phase rotation coefficient are slided window, in the time that has prefix arrival, the register shift of sliding window correlator, and input signal and scrambler signal correction; In time outside this scope, the register shift of sliding window correlator, but that sliding window correlator is not done is relevant, does not have signal output.
4, as claim 2 or 3 described Wideband Code Division Multiple Access (WCDMA) prefix detectors, it is characterized in that: described sliding window correlator is relevant respectively the real part imaginary part of scrambler and input signal, and correlated results is divided into two-way input accumulator.
5, as claim 2 or 3 described Wideband Code Division Multiple Access (WCDMA) prefix detectors, it is characterized in that: in described decision device, the Hadamard code conversion correlation square summation of the real part of each signature, imaginary part, compare with judgement threshold, if greater than judgement threshold, then thinking has the prefix of a corresponding signature to arrive on this position; Otherwise thinking does not have the corresponding prefix of this signature to arrive on the relevant position.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB021121052A CN1323501C (en) | 2002-06-17 | 2002-06-17 | Prefix detector for WCDMA |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB021121052A CN1323501C (en) | 2002-06-17 | 2002-06-17 | Prefix detector for WCDMA |
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| Publication Number | Publication Date |
|---|---|
| CN1464658A true CN1464658A (en) | 2003-12-31 |
| CN1323501C CN1323501C (en) | 2007-06-27 |
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| CNB021121052A Expired - Lifetime CN1323501C (en) | 2002-06-17 | 2002-06-17 | Prefix detector for WCDMA |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1925377B (en) * | 2005-08-29 | 2011-11-30 | 中兴通讯股份有限公司 | Device and method for generation of WCDMA descending multiple scrambling codes |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6643281B1 (en) * | 1998-03-05 | 2003-11-04 | At&T Wireless Services, Inc. | Synchronization preamble method for OFDM waveforms in a communications system |
| FR2791495B1 (en) * | 1999-03-26 | 2001-05-04 | France Telecom | METHOD FOR SYNCHRONIZING THE RHYTHM OF A DIGITAL SIGNAL |
| EP1059818B1 (en) * | 1999-06-11 | 2007-02-21 | Texas Instruments Incorporated | Improved random access preamble coding for initiation of wireless mobile communications sessions |
| EP1109326A1 (en) * | 1999-12-15 | 2001-06-20 | Lucent Technologies Inc. | Peamble detector for a CDMA receiver |
| EP1198075A3 (en) * | 2000-10-18 | 2004-12-01 | Texas Instruments Inc. | Method for maintaining timing in a CDMA rake receiver |
-
2002
- 2002-06-17 CN CNB021121052A patent/CN1323501C/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1925377B (en) * | 2005-08-29 | 2011-11-30 | 中兴通讯股份有限公司 | Device and method for generation of WCDMA descending multiple scrambling codes |
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| CN1323501C (en) | 2007-06-27 |
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Owner name: SHANGHAI ALCATEL-LUCENT CO., LTD. Free format text: FORMER NAME: BEIER AERKATE CO., LTD., SHANGHAI Owner name: BEIER AERKATE CO., LTD., SHANGHAI Free format text: FORMER NAME: BELL CO.,LTD., SHANGHAI |
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Address after: 201206 Pudong New Area Jinqiao Export Processing Zone, Nanjing Road, No. 388, Shanghai Patentee after: ALCATEL-LUCENT SHANGHAI BELL Co.,Ltd. Address before: 201206 Pudong New Area Jinqiao Export Processing Zone, Nanjing Road, No. 388, Shanghai Patentee before: Shanghai Bell Alcatel Co.,Ltd. Address after: 201206 Pudong New Area Jinqiao Export Processing Zone, Nanjing Road, No. 388, Shanghai Patentee after: Shanghai Bell Alcatel Co.,Ltd. Address before: 201206 Pudong New Area Jinqiao Export Processing Zone, Nanjing Road, No. 388, Shanghai Patentee before: Shanghai Bell Co.,Ltd. |
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Address after: 201206 Pudong New Area Jinqiao Export Processing Zone, Nanjing Road, No. 388, Shanghai Patentee after: NOKIA SHANGHAI BELL Co.,Ltd. Address before: 201206 Pudong New Area Jinqiao Export Processing Zone, Nanjing Road, No. 388, Shanghai Patentee before: ALCATEL-LUCENT SHANGHAI BELL Co.,Ltd. |
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Granted publication date: 20070627 |