Wireless Oom

The combination of different frequency, code and time specify a set of physical channels.

Two main categories: (1) dedicated and (2) control

1. Dedicated physical channels

a. DPDCH (Dedicated Physical Data Channel):

carries DCH transport channel.

As with DCH, this exists both in the uplink and downlink.

closed loop power control (1500 Hz/sec)

b. DPCCH (Dedicated Physical Control Channel):

relates to DPDCH and transmits physical layer signal information (e.g., power control commands and synch. sequences)

In the uplink, it is code multiplexed with DPDCH.

In the downlink, it is time multiplexed with DPDCH.

Note that this has nothing with DCH or DCCH or DTCH!

2. Physical control channels

a. P-CCPCH (Primary Common Control Physical Channel):

only in the downlink.

fixed bit rate of 30kbps (spreading factor 256)

carry the BCH transport channel.

b. S-CCPCH (Secondary Common Control Physical Channel):

carry the PCH and FACH transport channels.

only in the downlink.

different bit rates.

c. SCH (Synchronization Channel):

used for cell search and the first channel that UE needs to know.

allow synchronization at frame and code sequence of P-CCPCH.

d. CPICH (Common Pilot Channel):

transmits pre-defined bit sequence in downlink with 30kbps

allows UEs to measure power of cells

e. PRACH (Physical Random Access Channel):

uplink direction; carries RACH transport channel

open loop power control

f. HS-PDSCH (High Speed Physical Downlink Shared Channel):

carries HS-DSCH transport channel; multicode transmission with spreading factor 16

2ms frame with 3 slots

QPSK or 16-QAM

HARQ

g. HS-SCCH (High Speed Shared Control Channel):

fixed bit rate of 60kbps carry downlink signal for HS-DSCH.

Data will come soon.. be ready.

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No transport related but

a. AICH (Acquisition Indicator Channel):

used for PRACH response

b. PICH (Paging Indicator Channel):

this is associated with S-CCPCH to which a PCH channel is mapped.

carries paging indicator that inform UEs that they need to decode the information of the PCH channel.