modulation

How QPSK & BPSK Modulation in WCDMA?

A data-modulation scheme defines how the data bits are mixed with the carrier signal, which is always a sine wave. There are three basic ways to modulate a carrier signal...
Article Topics :

ask, bit, carrier, cdma, cell, digital, fsk, modulation, phase, psk, signal, telecom, where bpsk modulation scheme are used

Terminal Transmitting and Receiving Process in Wimax

Transmitting:  The process is similar to that of BS. The frequency offset is pre-corrected. The Ranging and BW Request are generated at the physical layer and a code is selected...
Article Topics :

mac layer, modulation, physical layer, ranging, telecom, transmitting, Wimax

BS Transmitting and Receiving Process in Wimax.

Transmitting:  After being processed at the MAC layer, the downlink data is sent to the physical layer inthe format of MAC PDU. The MAC PDU arranges the data block size...
Article Topics :

coding, downlink data, fdma, mac, modulation, ofdma, pdu, physical, radio resource, telecom, uplink

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...
Article Topics :

active, cdma, cell, code, handoff, interleaving, long, modulation, power, power control, power control in cdma, qpsk, scrambling, short, soft, softer

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...
Article Topics :

active, cdma, cell, code, handoff, interleaving, long, modulation, pn, power, power control, qpsk, scrambling, short, soft, softer

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...
Article Topics :

active, cdma, cell, code, handoff, interleaving, long, modulation, power, power control, qpsk, scrambling, short, soft, softer

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...
Article Topics :

air interface, amplitude, cdma, cdma modulation, hsdpa, modulation, qam, qpsk, signal, telecom, wcdma modulation, wcdma modulation qam

Processing Procedure of WCDMA System

Source coding can increase the transmitting efficiency. Channel coding can make the transmission more reliable. Spreading can increase the capability of overcoming interference. Through the modulation, the signals will transfer...
Article Topics :

Processing Procedure of WCDMA Systemcdma, CHANNEL, chip, coding, interleaving, modulation, signal, spreading, telecom

Soft/Softer Handoff in CDMA

Multi-path combination in the BSC during soft handoffMulti-path combination in the BTS during softer handoffs       Soft handoff means that during the handoff of a mobile station at the coverage...
Article Topics :

active, cdma, cell, code, gsm, handoff, interleaving, long, modulation, power, power control, qpsk, rake, scrambling, short, soft, softer

Forward Power Control in CDMA

Message Transmission Mode MS measures the frame quality and informs the base station to the result i.e. whether it is in the threshold or periodical  mode. Base station determines whether ...
Article Topics :

active, cdma, cell, code, handoff, interleaving, long, modulation, power, power control, power control in cdma, qpsk, scrambling, short, soft, softer

Scrambling (M) sequence in CDMA

  Two points are important here:  Maximum number of shift register (N)  Mask The period of out put sequence is 2N-1 bits Only sequence offset is change when the mask...
Article Topics :

active, cdma, cell, code, handoff, interleaving, long, modulation, pn, power, power control, qpsk, scrambling, short, soft, softer

Constellation in LTE

The QPSK is the most robust modulation. It can be represented by a constellation: The radius, R, represents the amplitude. The angle, ?, represents the phase. There are 1 amplitude...
Article Topics :

Constellation in LTE, amplitude, constellation, lte, modulation, phase, pn, qam, qpsk, radius, symbol, telecom

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