CN1812305A

CN1812305A - Interleaving method for reducing interference by synchronous channel signal

Info

Publication number: CN1812305A
Application number: CNA2005100051593A
Authority: CN
Inventors: 蔡华; 李必涛
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2005-01-28
Filing date: 2005-01-28
Publication date: 2006-08-02
Anticipated expiration: 2025-01-28
Also published as: CN100578995C

Abstract

This invention provides a kind of interleaving method for decreasing SCH interference. It is used for second interleaving process of data transmission. It concludes: the need interleaving data are read-in to the interleaving matrix of interleaving machine line by line. The number of columns of the used interleaving matrix C2 meets 15/C2<15%; the said interleaving matrix are controlled to undertake column exchanging by interleaving machine; the interleaved data are read out from the interleaving matrix column by column. The better C2=120 undertakes column exchanging, which uses the said C2=120 corresponded column exchanging rule. This invention can decrease interference of the SCH channel signal.

Description

The deinterleaving method that a kind of reduction is disturbed by synchronous channel signal

Technical field

The present invention relates to wireless channel coding and interleaving technology field, be meant the deinterleaving method that a kind of reduction is disturbed by synchronizing channel (SCH) signal especially.

Background technology

In the communication system that adopts the WCDMA technology, channel comprises dedicated channel and common signal channel, comprises Common Pilot Channel, paging channel etc. in the common signal channel.The dedicated channel and the most shared channel of different user communication usefulness all use identical period and frequency range, these channels generally adopt synchronized transmission, distinguish by incoherent " sign indicating number " between the down channel, for example adopt orthogonal variable spreading factor sign indicating number (OVSF).By adopting orthogonal code, make the interference ratio between down channel less.

And synchronizing channel (SCH) does not use channel code and scrambler to do spread processing, therefore the cross correlation value of SCH channel and other physical channel is bigger, other physical channels and the symbol on the SCH channel overlap zone will be compared non-symbol that should the zone bigger interference, that is to say that the SCH channel has constituted an interference to other channels.Specifically referring to the schematic diagram of the SCH synchronizing signal shown in the A of Fig. 1.

As shown in Figure 1, a radio frames is 10ms among the WCDMA, and 38400 chips are divided into 15 time slots.And the SCH signal takies preceding 256 chips of each time slot.Like this, in time, it is the cycle with the time slot that synchronizing channel (SCH) is exactly one, duty ratio is the sequence of 256/2560=1/10, owing to do not adopt orthogonal code, for the signal frame of other channels in the wireless channel, it is the interference signal in cycle with the time slot that SCH has constituted one.

In WCDMA, comprise interleaving process in the channel coding/decoding 2 times, first interweaves is interweaving in the transmission channel TTI, between radio frames, interweaving for the second time is interweaving in the physical channel radio frames.Above content can be referring to 3GPP TS25.212V5.4.0.

Find that by test in some cases, a kind of type of service of following TR34.108: the ftp file in download, under the wireless access 384K business, chipoffset=2560 is under the situation that power control employing 384K business is controlled.3.4K the signaling (channel associated signalling) of radio layer three after handling through a series of channel coding/decoding, half symbol of this signaling drops on the overlapping areas with SCH fully, and the signal that drops on the overlapping region has been subjected to the serious interference of SCH channel according to the analysis of front, cause 3.4K signaling error code too high, and often fall chain.

Summary of the invention

In view of this, the deinterleaving method that main purpose of the present invention is to provide a kind of reduction disturbed by the SCH signal, make reduce the 3.4K signaling fall the chain rate.

A kind of reduction provided by the invention is subjected to the deinterleaving method of SCH signal interference, is used for the interleaving process second time of transfer of data, comprising:

Data to be interweaved are write line by line in the interleaver matrix of interleaver, wherein, the columns C2 of described interleaver matrix satisfies 15/C2＜15%;

Interleaver is controlled described interleaver matrix and is listed as exchange;

By row sense data from interleaver matrix.

Wherein, the columns C2 of described interleaver matrix is 120, uses the pairing rank transformation rule of C2=120 to carry out rank transformation during described rank transformation.

Wherein, described deinterleaving method is applied to the WCDMA communication system.

By said method as can be seen, the present invention is made in the interleaving process second time, uses appropriate C 2, thereby makes the more average of data dispersion, thereby has reduced the influence that interference caused of SCH signal.Fall the chain rate when further having reduced WCDMA high speed data service (384Kbps), and do not need extra technology.From the result of laboratory tests, will fall the chain rate and drop to below 0.1% from present 5%, improved the Radio Link overall performance, improved the stability of WCDMA data service.

Description of drawings

Fig. 1 is a SCH synchronizing signal schematic diagram.

Fig. 2 sends to the flow chart of wireless channel for the down link data framing.

Fig. 3 is the data transmission procedure schematic diagram.

The distribution map that Fig. 4 distributes for data and the SCH signal period concerns.

Fig. 5 is the present invention's flow chart that interweaves.

Embodiment

At first, the reason of the interference that the SCH channel is caused is analyzed.

Down link data framing as shown in Figure 2 sends to the flow chart of wireless channel, before data send to wireless channel, from the data of different transmission channels through the transmission channel cascade multiplexing after, need carry out interweave the second time (2nd Interleaving), upsetting the mutual order of these data, break up with the poly-heap error code of the burst that will in the wireless channel transmission, occur.Interleaving technology specifically can only carry out brief introduction below referring to 3GPP TS25.212V5.4.0 for the second time.

The process that interweaves for the second time mainly comprises: data being write at first line by line inside the matrix of (N * 30), is C2=30 according to agreement.Matrix is listed as exchange then, reads by row again.Wherein the inner array exchange regulation of C2=30 correspondence is as follows: establish original column number and be 0,1 ..., 29, then the row after the row exchanges are＜0,20,10,5,15,25,3,13,23,8,18,28,1,11,21,6,16,26,4,14,24,19,9,29,12,2,7,22,27,17 in proper order 〉.

Below with reference to Fig. 2, and the data transmission procedure schematic diagram shown in Fig. 3, and to be multiplexed into a physical channel with WCDMA system transmissions channel B, A be that example describes this interleaving process.Suppose that these two transport channel data are respectively B1, B2 ... B30; A31, A32 ..., described second time, interleaving process may further comprise the steps:

At first, it is multiplexing that the channel multiplexing unit carries out cascade with transmission channel B, the A of input, obtain carrying out the data that interweave for the second time for＜B1, B2 ... B30, A31, A32 ....

Data write the interleaver matrix of interleaver memory line by line then, and the result is as follows:

0 1 2 ... 28 29

[\begin{matrix} B 1 & B 2 & B 3 & \cdot \cdot \cdot & B 29 & B 30 \\ A 31 & A 32 & A 33 & \cdot \cdot \cdot & A 59 & A 60 \\ \cdot \cdot \cdot & \cdot \cdot \cdot & \cdot \cdot \cdot & \cdot \cdot \cdot & \cdot \cdot \cdot & \cdot \cdot \cdot \\ \cdot \cdot \cdot & \cdot \cdot \cdot & \cdot \cdot \cdot & \cdot \cdot \cdot & \cdot \cdot \cdot & \cdot \cdot \cdot \end{matrix}]

Carry out rank transformation, the result is as follows:

0 20 10 ... 27 17

[\begin{matrix} B 1 & B 21 & B 11 & \cdot \cdot \cdot & B 28 & B 18 \\ A 31 & A 51 & A 41 & \cdot \cdot \cdot & A 58 & A 48 \\ \cdot \cdot \cdot & \cdot \cdot \cdot & \cdot \cdot \cdot & \cdot \cdot \cdot & \cdot \cdot \cdot & \cdot \cdot \cdot \\ \cdot \cdot \cdot & \cdot \cdot \cdot & \cdot \cdot \cdot & \cdot \cdot \cdot & \cdot \cdot \cdot & \cdot \cdot \cdot \end{matrix}]

Then, data are read by row from the interleaver matrix of interleaver memory, send in the wireless channel, this Frame of reading (specifically can referring to Fig. 4) as follows:

<B1A31...B21A51 B11A41.........B28A58...B18A4...>

Analyze above interleaving process, from interleaver matrix as can be seen: after the transmission channel cascade write interleaver matrix, transmission channel B data can write on first row of interleaver matrix, and what several row in back write is the data of transmission channel A.Row exchange wherein can not change the layout of these data.And just because of this layout, when reading the data of interleaver matrix by row, the Frame of reading all is to form according to " BAAAA...... " format permutation by 30 groups.And every frame data are made up of 15 time slots for WCDMA, and are 30 groups according to the data that top interleaver matrix is read, half time slot in every group of just in time corresponding frame like this, and promptly per two data set correspondences are in a time slot, specifically referring to shown in Figure 4.Therefore in same time slot, be distributed as to the B data centralization 2 sections zones, wherein one section zone is disturbed by SCH fully.

And the radio layer signaling of above-mentioned 3.4K promptly can be interpreted as data carried by data among the channel B shown in Figure 4, therefore caused after deinterleaving, the radio layer signaling of the channel B that obtains carrying, the data that have half have been polluted by SCH, do not reach the effect of the SCH channel disturbance of resisting self sub-district.

By above-mentioned analysis, can find, because the frame data of WCDMA have comprised 15 time slots, C2=30 in the interleaving process for the second time, data are divided for 30 groups, so the two columns certificates that can carry the matrix of C2=30 in each time slot are still analyzed with Fig. 4, what tentation data B partly carried is described signaling-information, then as can be seen, the disturbed situation of data B is 15/30, is 50%.

Based on above analysis, the C2 that the present invention will have now in the algorithm that interweaves changes to 120 times by 30 times, and employing C2=30 the time correspondence inner array exchange regulation (Inter-column permutationpattern for 2nd interleaving).

Like this, after C2 changes to 120 times, in 1 Frame, though still can be subjected to the interference of 15 times SCH channel, but data B can be divided into 120 times, thereby, the overlapping situation of appearance and SCH at most also is 15/120=12.5%, compares with original 50% Duplication, has significantly reduced; And 12.5% is also more approaching substantially than row with shared 10% (with reference to 10% duty ratio of analyzing in the prior art) of SCH.

Be understood that C2 also can be other values, for example 60,90,150 etc.C2 be 60,90,150 o'clock correspondences be respectively 15/60=25%, 15/90=16.7%, 15/150=10% with the overlapping ratio of SCH.Test result shows, when being disturbed by the SCH signal less than 15% symbol, falls chain probability only below 0.1% in the 3.4K signaling, considers that simultaneously the increase of C2 causes the complexity of interleaving process, so adopted 120 in the present embodiment as the more suitable value of C2.Certainly, consider according to the equilibrium of the error rate and the complexity that interweaves, and communication system is to the requirement of the error rate, C2 can select other value.

Referring to Fig. 5, specifically, when data to be interweaved after multiplexing were write the interleaver matrix of interleaver memory line by line, employed C2=30 was revised as C2=120 when the present invention interweaved the secondary in the former agreement, and what that is to say use is the interleaver matrix of 120 row.Corresponding interleaver is controlled described interleaver matrix and is listed as when exchanging, and the inner array exchange regulation uses the inner array exchange regulation of C2=120 correspondence, specifically sees table 1.Pursue again behind the rank transformation and be listed as the data of reading after interweaving.

The C2 value	Inner array exchange regulation＜P2 (0), P2 (1) ..., P2 (C2-1) 〉
The C2 value		120	<0，60，30，90，20，80，50，100，10，70，40，110，5，65，35，95，15，75， 45，105，25，85，55，115，3，63，33，93，13，73，43，103，23，83，53， 113，8，68，38，98，18，78，48，108，28，88，58，118，1，61，31，91，11， 71，41，101，21，81，51，111，6，66，36，96，16，76，46，106，26，86， 56，116，4，64，34，94，14，74，44，104，24，84，54，114，19，79，49， 109，9，69，39，99，29，89，59，119，12，72，42，102，2，62，32，92，7， 67，37，97，22，82，52，112，27，87，57，117，17，77，47，107>

Table 1

According to found that of laboratory tests, when the symbol of 3.4K signaling 50% is disturbed by the SCH signal, have 25% probability and fall chain.And further according to the distribution principle of Chipoffset, the business under the 384K speed, the probability that the symbol of 3.4K signaling 50% is disturbed by the SCH signal has 20%, so fall the actual 20% * 25%=5% of being of chain probability.And same test result shows, if in the 3.4K signaling when being disturbed by the SCH signal less than 15% symbol, fall chain probability only below 0.1%.

From test result as can be seen, fall the chain rate when the present invention can reduce WCDMA high speed data service (384Kbps), significantly suppressed the interference of SCH each transmission channel.Thereby improve the performance of decode procedure, further realize improving the overall performance of Radio Link.

The above only is preferred embodiment of the present invention, and is in order to restriction the present invention, within the spirit and principles in the present invention not all, any modification of being done, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims

1, a kind of reduction is subjected to the deinterleaving method that the synchronous channel SCH signal disturbs, and is used for the interleaving process second time of transfer of data, it is characterized in that, comprising:

By row sense data from interleaver matrix.

2, method according to claim 1 is characterized in that, the columns C2 of described interleaver matrix is 120, uses the pairing rank transformation rule of C2=120 to carry out rank transformation during described rank transformation.

3, method according to claim 1 is characterized in that, described deinterleaving method is applied to the WCDMA communication system.