CN1988428B - Method and device for generating orthogonal variable extension frequency factor code in wideband CDMA system - Google Patents

Abstract

This invention discloses a method and a device for generating orthogonal variable spread spectrum factor codes of WCDMA, in which, said device includes an orthogonal variable spread spectrum factor code tree storage with 16 spread spectrum factors, a channel code number analysis module, a code tree selection module, a multiplier module and an orthogonal variable spread spectrum factor code counter, and the channel code number analysis module is used in analyzing input channel code number into two channel numbers with corresponding spreqd spectrum factors of 16 to read corresponding number from the code tree list storage.

Description

The method and apparatus that orthogonal variable extension frequency factor code in wideband CDMA system generates

Technical field

The present invention relates to the baseband processor method and apparatus of a kind of broadband CDMA system (WCDMA), the implementation method of in particular a kind of Orthogonal Variable Spreading Factor OVSF (OVSF) of base station multiplex (MUX) parallel processing situation sign indicating number, with and the hardware implement device.

Background technology

In the WCDMA system, the down link of Orthogonal Variable Spreading Factor OVSF (OVSF) sign indicating number respective cell is used for distinguishing channel, also distinguishes with it between the DPCH of the uplink channel of mobile phone.Move partnership (3GPP) at the third generation strict regulation has been done in the generation of the ovsf code of broadband CDMA system.3GPP definition ovsf code tree sees shown in Figure 1, C among the figure _{Ch, SF, k}For a channel is unique, and wherein SF is meant the spreading factor of ovsf code, and the SF value is 4,8,16,32,64,128 and 256 7 altogether in the WCDMA system, and k is a channel code number.

The common generation way of ovsf code is to adopt the mode of iteration, that is:

C _ch，1，0＝1，

$\left[\begin{array}{c}{C}_{\mathrm{ch},\mathrm{2,0}}\\ C_{\mathrm{ch},\mathrm{2,1}}\end{array}\right]=\left[\begin{array}{cc}{C}_{\mathrm{ch},\mathrm{1,0}}& C_{\mathrm{ch},\mathrm{1,0}}\\ C_{\mathrm{ch},\mathrm{1,0}}& {-C}_{\mathrm{ch},\mathrm{1,0}}\end{array}\right]=\left[\begin{array}{cc}1& 1\\ 1& -1\end{array}\right],$

$\left[\begin{array}{c}{C}_{\mathrm{ch},2^{(n+1)},0}\\ C_{\mathrm{ch},2^{(n+1)},1}\\ C_{\mathrm{ch},2^{(n+1)},2}\\ C_{\mathrm{ch},2^{(n+1)},3}\\ M\\ C_{\mathrm{ch},2^{(n+1)},2^{(n+1)}-2}\\ C_{\mathrm{ch},2^{(n+1)},2^{(n+1)}-1}\end{array}\right]=\left[\begin{array}{cc}{C}_{\mathrm{ch},2^n,0}& C_{\mathrm{ch},2^n,0}\\ C_{\mathrm{ch},2^n,0}& {-C}_{\mathrm{ch},2^n,0}\\ C_{\mathrm{ch},2^n,1}& C_{\mathrm{ch},2^n,1}\\ C_{\mathrm{ch},2^n,1}& {-C}_{\mathrm{ch},2^n,1}\\ M& M\\ C_{\mathrm{ch},2^n,2^n-1}& C_{\mathrm{ch},2^n,2^n-1}\\ C_{\mathrm{ch},2^n,2^n-1}& {-C}_{\mathrm{ch},2^n,2^n-1}\end{array}\right]$

Obvious this method realizes with hardware, when SF is bigger, needs the bigger resource or the iteration of long time one-level one-level, can waste a large amount of resources and time.

Also having a kind of method in addition is according to the characteristic that distortion had of ovsf code as walsh code, adopt the binary system bit position of sign indicating number number of channel and the value of SF, produce ovsf code through some combinational circuits, but this method once can only produce the ovsf code of 1bit, and be that order generates, and for the base station system of supporting the multi-user, use time-multiplexed hardware structure mostly, the each processing is that many bit handle, therefore corresponding this method need produce ovsf code in advance, parallel series stores, these code words of parallel read-out when base station system treat.

Therefore this way needs certain ovsf code memory space, therefore needs more resource, and need produce and store ovsf code in advance, so increased the complexity of control.

Summary of the invention

The method and apparatus that the purpose of this invention is to provide the ovsf code generation of a kind of WCDMA, generate complicated in order to overcome the prior art ovsf code, and the code word that produces many bit simultaneously need be than the shortcoming of large resource, a kind of new implementation structure is proposed, save the hardware resource expense, make and to produce 2 simultaneously ⁿThe ovsf code word of bit length.

Technical scheme of the present invention comprises:

The device that a kind of orthogonal variable extension frequency factor code in wideband CDMA system generates, wherein, comprise that a spreading factor is 16 orthogonal variable spread-spectrum factor code tree table memory, channel code decomposing module, code tree selection module, multiplication module, orthogonal variable frequency extension factor code word counter; And

Described channel code decomposing module is used for according to decomposition formula

It is 16 channel code number that the channel code of input number is resolved into two corresponding spreading factors, and from being 16 orthogonal variable spread-spectrum factor code tree table memory, reads spreading factor the codeword sequence of corresponding orthogonal variable frequency extension factor code number with new channel code number, in the described decomposition formula, k is a channel code number, SF is the spreading factor of orthogonal variable frequency extension factor code, m and n be the sign indicating number number;

Described orthogonal variable frequency extension factor code word counter control code tree selects module to be used for selecting from the codeword sequence of an orthogonal variable frequency extension factor code number according to the high order bit of orthogonal variable frequency extension factor code word counter the word bit of required bit wide, in multiplication module, carry out multiplying with the codeword sequence of another orthogonal variable frequency extension factor code number, export the orthogonal variable frequency extension factor code word sequence of many bits of respective channels sign indicating number number at last.

The method that a kind of orthogonal variable extension frequency factor code in wideband CDMA system generates, it comprises the steps:

A, use the channel code decomposing module with channel code number according in the channel code decomposing module that do not coexist of spreading factor according to decomposition formula

Resolve into two sign indicating numbers number, in the described decomposition formula, k is a channel code number, and SF is the spreading factor of orthogonal variable frequency extension factor code, and m and n are sign indicating number number;

B, number giving spreading factor with two sign indicating numbers is 16 orthogonal variable spread-spectrum factor code tree table memory, selects the orthogonal variable frequency extension factor code word sequence A to 16 word bits that should two yards numbers from spreading factor is 16 orthogonal variable spread-spectrum factor code tree table memory _mAnd A _n

C, code tree is selected the high-order word bit of module according to the orthogonal variable frequency extension factor code word counter, from orthogonal variable frequency extension factor code word sequence A _nIn select corresponding s position word bit;

D is with the orthogonal variable frequency extension factor code word sequence A of 16 word bits of sign indicating number m correspondence _m, with orthogonal variable frequency extension factor code word sequence A _nIn select corresponding s position word bit and in multiplication module, carry out multiplying;

E, output be exactly the orthogonal variable frequency extension factor code word sequence of the multiword position of corresponding actual channel code number.

Described method, wherein, described step C also comprises:

The each orthogonal variable frequency extension factor code word that produces of described orthogonal variable frequency extension factor code word counter is to count in the cycle with 256.

The method and apparatus that a kind of orthogonal variable extension frequency factor code in wideband CDMA system provided by the present invention generates, realized the generation of the ovsf code of parallel many bit, the resource that realizes is far smaller than the ovsf code maker of the single bit of many covers, especially control is very simple, can when needing, code word produce corresponding ovsf code word at once, and do not need to produce in advance and store, saved stored resource, reduced producing the control circuit resource that the ovsf code word is increased in advance simultaneously, and can number can produce corresponding ovsf code word channel code arbitrarily.

Description of drawings

Fig. 1 is the ovsf code tree structure schematic diagram of the WCDMA system of prior art;

Fig. 2 is a WCDMA provided by the invention system ovsf code generation method flow graph;

Fig. 3 is the WCDMA ovsf code implement device figure of system provided by the invention;

Embodiment

Below in conjunction with accompanying drawing, will carry out comparatively detailed explanation to each preferred embodiment of the present invention.

In the method and apparatus that described orthogonal variable extension frequency factor code in wideband CDMA system OVSF of the present invention generates, for ovsf code, corresponding all SF have a least common multiple, be exactly 256, that is to say all OVSF all with 256 as a code word cycle.

Therefore all ovsf codes no matter how many SF is, can be regarded 256 length as.Simultaneously by analysis, in the ovsf code tree table that per 16 code words of the ovsf code word of 256 length all are SF=16 to the ovsf code word.Therefore 256 the code word ovsf code word that can regard certain two 16bit length in the ovsf code tree table of SF=16 as generates by multiplying, therefore only needs the ovsf code that the code tree table memory of channel code decomposer, SF=16 and multiplication module etc. just can the many bit of disposable generation.

Accompanying drawing 1 is the ovsf code tree structure schematic diagram of WCDMA system.As can be seen from the figure, the characteristics of ovsf code word mainly contain: along with the increase of SF value, code tree branch is many more, and code tree branch equals the SF value, and the channel code span of each code tree branch correspondence is 0～SF-1 simultaneously.Therefore when SF=256, one has 256 branch's code trees, 0～255 the channel code of each code tree correspondence SF=256 number, and the ovsf code of each code tree branch has 256bit.

Each code tree branch (correspondence code n) can only be divided into 2 branches, and Dui Ying channel code number is 2n and 2n+1 respectively, and the bit figure place of each branch is 2 times of source branch.Wherein the code word of 2n branch is 2 times of bit figure places that the code word of n branch repeats once to form; And the first half code word is the code word of n branch in the code word of 2n+1 branch, and half code word of back is the code word negate of n branch.

Not have the ovsf code of same branches code tree be quadrature in the inventive method any two.Following table is the ovsf code tree table of whole 0～15 channel codes number of SF=16.One has 16 branches, and there is 16bit in each branch, and any two 16bit of branch are quadratures.

C 16，0	＝	1，1，1，1，1，1，1，1，1，1，1，1，1，1，1，1
			C 16，1	＝	1，1，1，1，1，1，1，1，-1，-1，-1，-1，-1，-1，-1， -1
C 16，2	＝	1，1，1，1，-1，-1，-1，-1，1，1，1，1，-1，-1，-1， -1
			C 16，3	＝	1，1，1，1，-1，-1，-1，-1，-1，-1，-1，-1，1，1，1， 1

C 16，4	＝	1，1，-1，-1，1，1，-1，-1，1，1，-1，-1，1，1，-1， -1
			C 16，5	＝	1，1，-1，-1，1，1，-1，-1，-1，-1，1，1，-1，-1，1， 1
C 16，6	＝	1，1，-1，-1，-1，-1，1，1，1，1，-1，-1，-1，-1，1， 1
			C 16，7	＝	1，1，-1，-1，-1，-1，1，1，-1，-1，1，1，1，1，-1， -1
C 16，8	＝	1，-1，1，-1，1，-1，1，-1，1，-1，1，-1，1，-1，1， -1
			C 16，9	＝	1，-1，1，-1，1，-1，1，-1，-1，1，-1，1，-1，1，-1， 1
C 16，10	＝	1，-1，1，-1，-1，1，-1，1，1，-1，1，-1，-1，1，-1， 1
			C 16，11	＝	1，-1，1，-1，-1，1，-1，1，-1，1，-1，1，1，-1，1，
		-1
			?C 16，12	＝	1，-1，-1，1，1，-1，-1，1，1，-1，-1，1，1，-1，-1， 1
?C 16，13	＝	1，-1，-1，1，1，-1，-1，1，-1，1，1，-1，-1，1，1， -1

?C 16，14	＝	1，-1，-1，1，-1，1，1，-1，1，-1，-1，1，-1，1，1， -1
			?C 16，15	＝	1，-1，-1，1，-1，1，1，-1，-1，1，1，-1，1，-1，-1， 1

Accompanying drawing 2 is WCDMA provided by the invention system ovsf code generation method flow graphs; The ovsf code method for generation of WCDMA of the present invention, it comprises the steps:

At first use the channel code decomposing module that channel code k is decomposed, resolve into two sign indicating number m and n in the sign indicating number decomposing module that do not coexist according to the SF of correspondence during decomposition, wherein

Secondly two sign indicating number m and n are given the ovsf code tree table memory of SF=16, from the ovsf code tree table memory of SF=16, select the ovsf code word sequence A of the 16bit of correspondence code m and n _mAnd A _n

Code tree is selected the high-order bit of module according to the ovsf code word counter then, from ovsf code word sequence A _nIn select corresponding s position bit; Wherein the code word control counter is to count in the cycle the ovsf code word that device produces with 256 at every turn.

Follow ovsf code word sequence A with the 16bit of sign indicating number m correspondence _m, with ovsf code word sequence A _nIn select corresponding s position bit and in multiplication module, carry out multiplying.

What export at last is exactly the ovsf code word sequence of many bit of the actual channel code k of correspondence.

Accompanying drawing 3 is WCDMA ovsf code implement device figure of system provided by the invention.The channel code k of a channel in the correspondence WCDMA system, its is through after channel code decomposing module, and k presses with channel code Mode resolve into sign indicating number m and the n of 2 corresponding SF=16, wherein m is the channel code number of 8bit High 4bit, n is Low 4bit.

These two sign indicating number m and n deliver in the ovsf code tree table memory of SF=16 then, select corresponding C respectively according to these two sign indicating number m and n from code tree table memory _{Ch, 16, m}And C _{Ch, 16, n}The ovsf code word sequence of two 16bit of branch is used array A respectively _mAnd A _nExpression.

Array A wherein _mDirectly deliver to and participate in multiplying in the multiplication module.And for array A _n, then need to select module according to the high 4bit control code tree of ovsf code word counter, select corresponding s position bit to deliver in the multiplier module of back and array A _mCarrying out step-by-step multiplies each other.Multiplied result is exactly the C of channel code k correspondence _{Ch, SF, k}The ovsf code word sequence of many bit of branch.

For the ovsf code word counter, because the least common multiple of all ovsf code words is 256bit, so counter is the 8bit counter, counting 0～255, the numerical value that each counting adds is the bit quantity of once exporting.

Below by the various SF of bright correspondence for instance, processing procedure of the present invention.If channel code k=3, corresponding respectively below 4,32 and 256 these several SF illustrate processing procedure of the present invention.

For SF=4, as channel code k=3, then corresponding C _{Ch, 4,3}The ovsf code word be (1 ,-1 ,-1,1), then the ovsf code word length of 256bit is that (1 ,-1 ,-1,1) repeats 64 times result.For the present invention, according to sign indicating number decomposing module decomposition formula

Decompose channel code k and obtain m=12, n=0.Then from the code tree table memory of corresponding SF=16, can obtain A _m=(1 ,-1 ,-1,1,1 ,-1 ,-1,1,1 ,-1 ,-1,1,1 ,-1 ,-1,1),

Therefore control the A that code tree selects module to select according to the OVSF count value _nValue and A _mCarry out step-by-step and multiply each other in multiplication module, the ovsf code word of the 256bit that obtains at last just equals the result that code word (1 ,-1 ,-1,1) repeats 64 times.

For SF=32, as channel code k=3, Dui Ying C then _{Ch, 32,3}The ovsf code word be

Then the ovsf code word length of 256bit is

Repeat 8 times result.For the present invention, according to sign indicating number decomposing module decomposition formula Decompose channel code k and obtain m=1, n=8.Then from the code tree table memory of corresponding SF=16, can obtain

A _n=(1 ,-1,1 ,-1,1 ,-1,1 ,-1,1 ,-1,1 ,-1,1 ,-1,1 ,-1).Therefore control the A that code tree selects module to select according to the OVSF count value _nValue and A _mCarry out step-by-step and multiply each other in multiplication module, the ovsf code word of the 256bit that obtains at last just equals code word Repeat 8 times result.

For SF=256, as channel code k=3, Dui Ying C then _{Ch, 256,3}The ovsf code word be It is the ovsf code word length of 256bit.For the present invention, according to sign indicating number decomposing module decomposition formula Decompose channel code k and obtain m=0, n=3.Then from the code tree table memory of corresponding SF=16, can obtain

A _n=(1,1,1,1 ,-1 ,-1 ,-1 ,-1 ,-1 ,-1 ,-1 ,-1,1,1,1,1).Therefore control the A that code tree selects module to select according to the OVSF count value _nValue and A _mCarry out step-by-step and multiply each other in multiplication module, the ovsf code word of the 256bit that obtains at last just equals code word

The method and apparatus that a kind of orthogonal variable extension frequency factor code in wideband CDMA system provided by the present invention generates, owing to adopted the ovsf code tree table memory of a SF=16, the channel code decomposing module, code tree is selected module, multiplication module, the ovsf code word counter, realized the generation of the ovsf code of parallel many bit, and the resource that realizes is far smaller than the ovsf code maker of the single bit of many covers, especially control is very simple, can when needing, code word produce corresponding ovsf code word at once, and do not need to produce in advance and store, saved stored resource, reduced producing the control circuit resource that the ovsf code word is increased in advance simultaneously, and can number can produce corresponding ovsf code word channel code arbitrarily.

Should be understood that above-mentioned description at specific embodiment is comparatively detailed, can not therefore be interpreted as the restriction to scope of patent protection of the present invention, scope of patent protection of the present invention should be as the criterion with claims.

Claims (3)

1. the device that generates of an orthogonal variable extension frequency factor code in wideband CDMA system, it is characterized in that, comprise that a spreading factor is 16 orthogonal variable spread-spectrum factor code tree table memory, channel code decomposing module, code tree selection module, multiplication module, orthogonal variable frequency extension factor code word counter; And

Described channel code decomposing module is used for according to decomposition formula

It is 16 channel code number that the channel code of input number is resolved into two corresponding spreading factors, and from being 16 orthogonal variable spread-spectrum factor code tree table memory, reads spreading factor the codeword sequence of corresponding orthogonal variable frequency extension factor code number with new channel code number, in the described decomposition formula, k is a channel code number, SF is the spreading factor of orthogonal variable frequency extension factor code, m and n be the sign indicating number number;

Described orthogonal variable frequency extension factor code word counter control code tree selects module to be used for selecting from the codeword sequence of an orthogonal variable frequency extension factor code number according to the high order bit of orthogonal variable frequency extension factor code word counter the word bit of required bit wide, in multiplication module, carry out multiplying with the codeword sequence of another orthogonal variable frequency extension factor code number, export the orthogonal variable frequency extension factor code word sequence of many bits of respective channels sign indicating number number at last.

2. the method that generates of an orthogonal variable extension frequency factor code in wideband CDMA system, it comprises the steps:

A, use the channel code decomposing module with channel code number according in the channel code decomposing module that do not coexist of spreading factor by

According to decomposition formula

Resolve into two sign indicating numbers number, in the described decomposition formula, k is a channel code number, and SF is the spreading factor of orthogonal variable frequency extension factor code, and m and n are sign indicating number number;

B, number giving spreading factor with two sign indicating numbers is 16 orthogonal variable spread-spectrum factor code tree table memory, selects the orthogonal variable frequency extension factor code word sequence A to 16 word bits that should two yards numbers from spreading factor is 16 orthogonal variable spread-spectrum factor code tree table memory _mAnd A _n

C, code tree is selected the high-order word bit of module according to the orthogonal variable frequency extension factor code word counter, from orthogonal variable frequency extension factor code word sequence A _nIn select corresponding s position word bit;

D is with the orthogonal variable frequency extension factor code word sequence A of 16 word bits of sign indicating number m correspondence _m, with orthogonal variable frequency extension factor code word sequence A _nIn select corresponding s position word bit and in multiplication module, carry out multiplying;

E, output be exactly the orthogonal variable frequency extension factor code word sequence of the multiword position of corresponding actual channel code number.

3. method according to claim 2 is characterized in that, also comprises among the described step C:

The each orthogonal variable frequency extension factor code word that produces of described orthogonal variable frequency extension factor code word counter is to count in the cycle with 256.