SMIQ
Digital Standard 3GPP W-CDMA (FDD)
1125.5555.03
E-9
2.221
Since the synchronization code symbol is defined as 11, the following is always true:
S
i
= S
q
.
The result is a BPSK mapping turned by 45° relative to the QPSK constellation of the S-CCPCH
component.
Since the synchronization code symbol is sent twice (in the primary and secondary SCH) with different
spreading, the signal power is doubled in this range.
The constellation diagram of the perch channel, therefore, has the following appearance:
Fig. 2-135
Constellation diagram of a signal consisting of P-CCPCH, P-SCH and S-SCH
The four circular areas are due to P-CCPCH ("QPSK"), the linear areas (diagonals) to SCH ("BPSK").
The spreading/constellation diagram of P-CPICH, S-CPICH, S-CCPCH, PICH, AP-AICH, AICH,
PDSCH, DL-DPCCH and DPCH are identical to the spreading/constellation diagram of P-CCPCH.
Envelopes
The following figures are based on a power of 0 dB.
To eliminate smearing of the amplitude due to the root cosine filter, all envelopes are calculated using a
squarewave filter.
The channels P-CPICH, S-CPICH, S-CCPCH, PICH, PDSCH feature a constant envelope during the
complete sequence.
Note:
Section 2.14.2.5, "Misuse TPC for output power control", describes how the envelope of
e.g. DPCHs can be varied.
The P-CCPCH is blanked during the first 256 chips of the slot.
Fig. 2-136
Envelope of P-CCPCH
