In This article you found Application of Tx diversity modes on UMTS downlink physical channel or in other word transmit diversity mode in UMTS. Transmitter-antenna diversity can be used to generate multi-path diversity in places where it would not otherwise exist. Multi-path diversity is a useful phenomenon, especially if it can be controlled. It can … Read more
Random Access Procedure in UMTS In This article I write about step of Physical random access procedure in umts. As shown in below figure steps is as below. Derive the available uplink access slots, in the next full access slot set, for the set of available UMTS RACH sub-channels within the given ASC. Randomly select … Read more
Cell Search Procedure purpose is to give the UE the possibility of finding a wcdma cell and of determining the downlink scrambling code and frame synchronization of that wcdma cell. This is typically performed in 3 steps: PSCH (Slot synchronization): The UE uses the SCH’s primary synchronization code to acquire slot synchronization to a wcdma … Read more
Here I Write about how the mapping can be done between logical, transport and physical channels. Not all physical channels are represented because not all physical channels correspond to a transport channel. The mapping between logical channels and transport channels is done by the MAC sub-layer. Different connections can be made between logical and transport … Read more
Carrying information to acknowledge downlink transport blocks and feedback information to the system for scheduling and link adaptation of transport block CQI and ACK/NACK Physical Channel, Uplink, SF=256 A High-Speed Dedicated Physical Control Channel, or HS-DPCCH, is the third uplink channel for WCDMA. It makes it possible for changing power relations between to the dedicated … Read more
Carries physical layer signaling to a single UE, such as modulation scheme (1 bit), channelization code set (7 bit), transport block size (6bit), HARQ process number (3bit), redundancy version (3bit), new data indicator (1bit), UE identity (16bit) HS-SCCH is a fixed rate (60 kbps, SF=128) downlink physical channel used to carry downlink signaling related to … Read more
HS-PDSCH in WCDMA mainly for 2 works, Bearing service data and layer 2 overhead bits mapped from the transport channel SF=16, can be configured several channels to increase data service HS-PDSCH High-Speed Physical Downlink Shared Channel is a channel added to UMTS to increase downlink data rates. This is defined in Release 5 of the … Read more
The uplink DPDCH and DPCCH are I/Q code multiplexed. But the downlink DPDCH and DPCCH is time multiplexed. This is main difference. Basically, there are two types of downlink DPCH. They are distinguished by the use or non use of the TFCI field. TFCI bits are not used for fixed rate services or when the … Read more
There are two kinds of uplink dedicated physical channels, the Dedicated Physical Data Channel (DPDCH) and the Dedicated Physical Control Channel (DPCCH). The DPDCH is used to carry the DCH transport channel. The DPCCH is used to carry the physical sub-layer control bits. Each DPCCH time slot consists of Pilot, TFCI，FBI，TPC Pilot is used to … Read more
Here I write about what is main work of Acquisition Indicator Channel AICH in 3G There is 2 types main work of AICH Carrying the Acquisition Indicators (AI), SF = 256 There are 16 kinds of Signature to generate AI The Acquisition Indicator Channel (AICH) is a common downlink channel used to control the uplink … Read more