4th Generation of cell phone

Ahmed shamel noori

Outline In this seminar we will discuss (G1, G2 , G3 , G4).

Advantage of generation .

drawback of generation.

1st generation technology (1G) First generation was an analog system .

Continuous in amplitude and time.

Variations in the signal-disrupts over long distances.

Developed in seventies.

Simplest type of wireless data.

Average between 4800 and 9600 bps(bit per second).

Advance Mobile phone system (AMPS) was first launched by US and is a 1G mobile system.

Based on FDMA (frequency division multiple access) , allows user to make voice calls in one country.

Drawback of 1 Generation (1G)

Poor voice quality.

Poor battery life.

Phone size big.

No security.

Frequent call drop.

Limited capacity.

Poor hand off reliability.

2nd Generation technology (2G)

Global system for mobile (GSM)

Was used in early 1990 in Europe.

GSM provided voice and limited data services and use digital modulation for improving audio quality.

The demand of fax, short message and data transmutation was grow rapidly.

2G digital technology divided into two standards :

TDMA (Time Division Multiple Access)GSM : Originally from Europe but used world wide.PDC : Used exclusively in japan.

CDMA (Code Division Multiple Access)Is-95: commonly referred as CDMA and used in US and part of Asia

Draw back of 2nd Generation

Need improve transmission quality.

Spotty coverage.

Unable to support complex data such as video.

Cell towers has a limited coverage area.

3th generation technology (3G)

Code division multiple access (CDMA)is a channel access method used by various radio communication

technologies.

CDMA is an example of multiple access :This mean several transmitters can send information simultaneously

over a single communication channel. This allows several users to share a band of frequencies (see bandwidth).

Problem of the interference between the users :CDMA employs spread-spectrum technology and a special coding scheme

(where each transmitter is assigned a code).

CDMA is used as the access method in many mobile phone standards, also called “CDMAOne", and its 3G evolution CDMA2000, are often

simply referred to as "CDMA"‘.

Generation of a CDMA signal

Problem with 3th Generation

High Bandwidth Requirement.

High Spectrum licensing.

Huge Capital.

4th Generation technology (4G)

4G is “MAGIC”

Mobile multimedia connection .

Anywhere Anytime with Anyone .

Global Mobility support .

Integrated wireless solutions .

Customized personal services .

LTE: Long-Term Evolution

Advantage Of 4G

Higher bandwidth enables a range of new application.

Lower cost than previous generations.

Faster and more reliable.

Video streaming.

Enhancement online gaming.

Location service-Gps.

The advantages of OFDM (Orthogonal frequency-division multiplexing) • Immunity to delay spread and multipath • Resistance to frequency selective fading • Simple equalization • Efficient bandwidth usage The disadvantages of OFDM • Synchronization needed • Need FFT units at transmitter, receiver • Sensitive to carrier frequency offset • High peak to average power ratio Limitations of OFDM • Timing synchronization error- If MC OFDM DS-CDMA system does not synchronize whole process then proper signal will not be received at receiver side. • Doppler frequency shift- Due to Doppler Effect, there will be offset in carrier frequency. • Frequency selective fading.

Thank you^_^