How QPSK & BPSK Modulation in WCDMA?
A data-modulation scheme defines how the data bits are mixed with the carrier signal, which is always a sine wave. There are three basic ways to modulate a carrier signal…
A data-modulation scheme defines how the data bits are mixed with the carrier signal, which is always a sine wave. There are three basic ways to modulate a carrier signal…
Location Area Identity (LAI) PAGING message is broadcast within a local area, the size of which depends on traffic, paging bearer capability, signaling flow , etc. Format: MCC+MNC+LAC MCC: Mobile…
Transmit Diversity MISO = Multiple Input Single Output Principle More complex than SISO. 2 or more transmitters and one receiver. MISO is more commonly referred to as transmit diversity. The…
Reverse Access Channel used by MS Initiate Communication or Respond to Paging Channel. A reverse channel is first spread with WALSH to 307.2Kbps and then becomes 1.2288Mcps after long code…
OVSF Code (Orthogonal Variable Spreading Factor) is used as channelization code Orthogonal codes are easily generated by starting with a seed of 1, repeating the 1 horizontally and vertically, and…
Forward Traffic Channel is used to Transmit Data and Signaling Information. Symbol repetition makes symbol streams at different rates adapted to those at the rate of 19.2k. The original symbol…
RACH(Random Access Channel) Uplink only. Used by the MS when making its first access to the Network. The reason for access could be initiation of a call or a page…
The paging channel transmits: System parameters message Access parameters Neighbors list CDMA channels list message The paging channel accomplishes: Paging to MS Assign traffic channel to MS The frame length…
A pilot channel: Assist mobile station to be connected with CDMA network Handles multi-path searching Provide the phase reference for coherent demodulation and help the mobile station estimate the transmission…
Diversity technology means that after receiving two or more input signals with mutually uncorrelated fading at the same time, the system demodulates these signals and adds them up. Thus, the…
Pilot Detection Threshold (T_ADD) Any Pilot that is strong but is not in the Handoff Direction Message is a source of interference. This Pilot should be immediately moved into the…