Tag Archives: cdma

WiMAX versus 3G and Wi-Fi

How does WiMAX compare with the existing and emerging capabilities of 3G and Wi-Fi? The throughput capabilities of WiMAX depend on the channel bandwidth used. Unlike 3G systems, which have

Narrowband Wireless Local-Loop Systems

Naturally, the first application for which a wireless alternative was developed and deployed was voice telephony. These systems, called wireless local-loop (WLL), were quite successful in developing countries such as

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 Modulation

Different modulation methods corresponding to different transmitting abilities in air interface. R99/R4: QPSK HSDPA: QPSK or 16QAM The UTRAN air interface uses QPSK modulation in the downlink, although HSDPA may

WCDMA Radio Interface Channel Definition

Logical Channel = information container  Defined by is transferred. Transport Channel = characteristics of transmission Described by and with data is transmitted over the radio interface . Physical Channel =

Process Gain in WCDMA

How Process Gain works in 3G? Process Gain = 10 Log (Chip rate/Bit Rate) Process gain differs for each service. If the service bit rate is greater, the process gain

WCDMA Network Architecture

WCDMA including the RAN (Radio Access Network) and the CN (Core Network). The RAN is used to process all the radio-related functions, while the CN is used to process all

CDMA Channel Frequencies & Calculation

The 850MHz CDMA band is most popularly used all over the world.This band as mentioned in the previous slide works between       824-849MHz Used for the Reverse link communication