SMIQ Digital Standard 3GPP W-CDMA (FDD)
1125.5555.03 E-92.211
2.14.2.9 WCDMA/3GPP Menu – Display of Code Domain and Code Domain
Conflicts
The channelization codes are taken from a code tree (see below).
The greater the spreading factor, the smaller the symbol rate and vice versa. The product of the spreading
factor and the symbol rate is constant and always equals the current chip rate. The outer branches of the
tree (right-most position in the figure) give the channelization codes for the lowest symbol rate (and so the
highest spreading factor). The use of a channelization code from the level with a spreading factor N blocks
the use of all other channelization codes from levels with spreading factor >N in the same branch of the
code tree. Channelization codes with a smaller spreading factor are contained in the codes with larger
spreading factor in the same code branch. If channelization codes of this type are used at the same time,
the signals of associated code channels will be mixed up to such an extent that they could not be
separated in the receiver and orthogonality would be lost.
Fig. 2-126 Code tree of channelization codes
Example: If in Fig. 2-126 code c
2,1
is already used, the remaining branch is blocked with c
4,1
and c
4,2
.
The outer branch region (with minimum symbol rate and max. spreading factor) which is based on the
channelization code selected in the code tree is defined as the domain of a certain channelization code.
Using a channelization code means that its entire domain is used. The whole domain ranges from 0 to
511 at the chip rate of 3.84 Mcps:
1
5.7
84.3
1
_min_
_
−=−=
ksps
Mcps
ratesymbol
rateChip
)
A graphic is displayed with the CODE DOMAIN menu item or the STATUS hardkey. This graphic shows
the occupancy of the code domain by the active code channels.
Fig. 2-127 WCDMA/3GPP – BS CONFIGURATION / CODE DOMAIN menu (without conflict)
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