UMTS Spreading Scrambling modulation

This tutorial on UMTS covers spreading, scrambing and modulation concepts.

Scrambling using scrambling code
Scrambling does not change the bit rate. It only helps in separating signals from different sources. Gold codes are used for this purpose as they have good correlation properties. Long and short type of scrambling codes are available. In the uplink it separates different UEs and in the downlink it s used for separation of cells/sectors.

DPCCH and DPDCH are BPSK modulated.

Synchronization using synchronization code:
These codes will have good auto correlation functionality hence are used for initial cell search and synchronization in the downlink. Primary sync. codes are derived using Golay sequence and secondary words from Hadamard sequence.

Similar posts on UMTS technology

Main Page  Architecture  Stack  channel types  Bands  UARFCN  Frame  Timers 

Other Wireless Tutorials

AMPS Tutorial   DECT Tutorial   Zigbee tutorial   GSM Tutorial   Multicarrier CDMA   CDMA tutorial   SCADA tutorial   GSM measurements   GSM RF Planning   wimax tutorial   wireless LAN tutorial   GPRS Tutorial   GPS Tutorial   TD-SCDMA Tutorial   LTE Tutorial   UMTS tutorial   HSPA tutorial