Here You Get how 3G work, Go inside WCDMA Technology and wcdma rf optimization.
Here I write about Iu PS Interface in WCDMA. WCDMA Protocol Structure for Iu PS The Iu PS protocol structure is represented in below image. Again, a common ATM transport is applied for both User and Control Plane. Also the physical layer is as specified for wcdma Iu CS. WCDMA Iu PS Control Plane Protocol … Read more
WCDMA Protocol Structure for Iu CS The WCDMA Iu CS overall protocol structure is depicted in below image. The three planes in the Iu interface share a common ATM (Asynchronous Transfer Mode) transport which is used for all planes. The physical layer is the interface to the physical medium: optical fiber, radio link or copper … Read more
The structure is based on the principle that the layers and planes are logically independent of each other. Protocol structures in UTRAN terrestrial interfaces are designed according to the same general protocol model. This model is shown in below. The structure is based on the principle that the layers and planes are logically independent of … Read more
WDMA Air interface or Uu Interface contains 3 layers which describe as follow, The WCDMA layer 1 supports all functions required for the transmission of bit streams on the physical medium. It is also in charge of measurements function consisting in indicating to higher layers, for example, WCDMA Frame Error Rate (FER), WCDMA Signal to … Read more
UTRAN (UMTS Terrestrial Radio Access network) structure The UTRAN consists of one or several Radio Network Subsystem ( RNS ), each containing one RNC and one or several NodeB. Interface Iu interface: the Iu interface connects the UTRAN to the CN and is split in two parts. The Iu-CS is the interface between the RNC … Read more
UMTS Closed Loop Mode Transmit Diversity Used in DPCH and HS-PDSCH. The closed-loop-mode transmit diversity can only be applied to the UMTS downlink channel if there is an associated UMTS uplink channel. Thus this mode can only be used with UMTS dedicated channels. The chief operating principle of the closed loop mode is that the … Read more
Time switching transmit diversity TSTD in UMTS is used only on UMTS SCH channel Time-switched transmit diversity (TSTD) can be applied to the UMTS SCH. Just like Space time block coding based transmit antenna diversity STTD, the support of Time switching transmit diversity is optional in the UMTS UTRAN, but mandatory in the UE. The … Read more
The TX diversity methods in the open-loop mode are as below Space time-block coding-based transmit-antenna diversity (STTD) Time-switched transmit diversity (TSTD). In UMTS STTD the data to be transmitted is divided between two UMTS transmission antennas at the base station site and transmitted simultaneously. The UMTS channel-coded data is processed in blocks of four bits. … Read more
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