Tag Archives: power control

GSM RF Optimization Step by Step

Here I write about GSM RF Optimization Step by Step and how to find KPI degradation and its solution. The RF network optimization process can be categorized by the following

What is 3G? or WCDMA?

3G is new upgraded cdma technology, in simple word its Wide band Code Devision Multiple Access Technology (WCDMA). This is first technology in which video call possible means voice and

Forward Traffic Channel of CDMA

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

LTE Downlink Logical Channel

Paging Control Channel(PCCH) A downlink channel that transfers paging information and system information change notifications. This channel isused for paging when the network does not know the location cell of

Dedicated Control Channel (DCCH) in GSM

SDCCH (Stand-alone Dedicated Control Channel) Uplink and Downlink. Used for call setup, authentication, ciphering location update and SMS. SACCH (Slow Associated Control Channel) Downlink and Uplink. Used to transfer signal

Specifications of WCDMA

Channel Bandwidth  5 MHz Duplex Mode  FDD and TDD Downlink RF Channel Structure  Direct Spread (DS) Chip Rate  3.84 Mcps Frame Length  10 ms Spreading Modulation  Balanced QPSK (downlink) Dual-channel

Main Characterictics of WCDMA

Support two basic modes: FDD and TDD modes High chip rate (3.84 Mcps) and data rates (up to 2 Mbps) Employs coherent detection on uplink and downlink based on the

Ranging in Wimax

Since each MS has a unique distance from the base station, it is critical in the uplink to synchronize the symbols and equalize the received power levels among the various

Types of Power Control in CDMA

Reverse power control Open loop power control Closed loop power control Inner loop power control:  800 Hz Outer loop power control Forward power control Message transmission mode: threshold transmission periodic

Long Code & Short Code In CDMA

The long code is a PN sequence with period of 242-1chips The functions of a long code: Scramble the forward CDMA channel Control the insertion of power control bit Spread

Interleaving in CDMA

It can be seen from the figure that the data are read row by row into an interleaver at the transmit end,read column by column out (this process is called

WCDMA Block Coding – CRC

Block coding is used to detect if there are any uncorrected errors left after error correction. The cyclic redundancy check (CRC) is a common method of block coding. Adding the