Enhanced Functions For Digital Standard 3GPP W-CDMA (FDD)
SMIQ
1125.5555.03
2.238
E-9
2.15.3
Enhanced Channels BS1/MS1
Enhanced Channels are channels which – in contrast to option SMIQB45 – are neither calculated nor
generated on the modulation coder but on the data generator. Up to four enhanced channels (or seven
with uplink mode) are possible where the maximum sequence length is calculated from the free list
memory and the number of channels:
Downlink:
38400
2
*
*
Channels
_
Enhanced
_
Of
_
Number
Bits
/
Memory
_
List
_
Data
_
Available
Frames
/
Length
_
Sequence
=
With maximum memory capacity, there are thus between 255 (4 DPCH) and 1022 (1 DPCH) frames.
In the downlink (possibly depending on memory capacity), a P-CCPCH/BCH with a continuous system
frame number (period 4096 frames) can also be generated at the same time as a DPCH (period 2044
frames) with a max physical rate of 30 ksps.
The simulation of higher rate channels (>30 ksps) together with the P-CCPCH/BCH is also supported
however with a reduced maximum sequence length of 500 frames.
(For a systematic list of all possible sequence lengths see description of SEQUENCE LENGTH
parameter, section
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Note:
This sequence length is sufficient for all performance tests in [1], section 8, since in these
tests the block error rate is measured.
Uplink:
38400
1
*
)
Channels
_
Enhanced
_
Of
_
Number
(
Bits
/
Memory
_
List
_
Data
_
Available
Frames
/
Length
_
Sequence
+
=
With maximum memory capacity, there are thus between 255 (DPCCH + 6 DPDCH) and 1022 (1 DPCCH
or 1 DPDCH) frames.
Note:
The higher number of channels in the uplink is possible through the BPSK data modulation.
These long sequences allow a physical
BER measurement (PN9) without a restart
of the BER tester
being required. An enhanced channel with a length of 511 frames is to be set.
If the maximum length of 1022 frames is used, BER measurements with channel coding and without
restart as required for receiver tests to [1], [3], [4] are possible.
Compared to the clearly enhanced sequence length range (max. 13 frames for SMIQB45), option
SMIQB48 offers the following advantages:
After generation of the sequence in the data generator
Data lists are available as data sources
for the
data fields and the TPC fields. Externally precoded data can be loaded into the SMIQ by the user, for
example to implement channel-coding schemes that are not supported by option SMIQB48.
Analogously, the long TPC lists are necessary to generate long non-repetitive power profiles.
Moreover, a base station can be simulated, which comprises a channel-coded P-CCPCH (BCH) and a
12.2 kbps reference measurement channel in addition to background and synchronization channels.
The system frame number (SFN) in BCH is automatically incremented in steps of two from 0 to 4094
(period 4096). The remaining system information of BCH can be filled from data lists, for example.
Another feature of enhanced channels is the possibility to generate the
reference measurement
channels
described in
[1], [3] and [4] and the AMR channels described in [5]. For a description see
The chip sequences of the enhanced channels are transmitted in binary form to the modulation coder
and are converted into (initially digital) I/Q levels in a mapper. This mapping can be switched by an
external input line (TTL, connected to LEVATT (PARDATA pin 9 or SMIQ-Z5)). The
channel powers of
the enhanced channels can be controlled in real time
, allowing the test of "SIR based closed loop
power control", for example. For further information see 2.15.3.1.3.
