Smart antenna made_by_nitmas_2008-12_batch

SMART ANTENNA

GROUP - 6

Group members Name Roll No

Subhabrata Biswas 18

Sourish Mukherjee 28

Souptik Roy 38

Ankit Pandey 55

Avishek Paul 56

Soumyajit Mazumdar 23

Contents Smart antenna array Why smart antenna array Elements of a smart antenna

Types of smart antenna Switched Lobe Dynamically phased array Adaptive array Application Advantage &Disadvantage Conclusion Reference

Antenna array with a digital signal processing capability to transmit and receive in an adaptive and spatially

sensitive manner.

Smart Antenna Array:

Higher Capacity

Higher Coverage

Higher bit rate

Improved link quality

Spectral efficiency

Mobility

Why Smart Antenna

Elements of a Smart Antenna

Number of radiating elements

A combining/dividing network

Control unit

Types of Smart Antennas

Switched lobe (SL)

Dynamically phased array (PA) antenna

Adaptive antenna array

Basic Working Mechanism

Technique in which the gain pattern of an adaptive array is steered to a desired direction through either beam steering

or null steering signal processing algorithms

Adaptive beam forming algorithms can provide

substantial gains (of the order of 10log(M) dB, where M is number of array elements)

Antenna Pattern of 7-element uniform equally spaced

circular array.

Beam-forming

Adaptive Beam-forming

An adaptive beam former is a device that is able to separate

signals co-located in the frequency band but separated in

the spatial domain. This provides a means for separating the desired

signal from interfering signals.

A two element adaptive array for interference suppression

Switched beam

Consists of a set of predefined beams.

Allows selection of signal from desired user.

Beams have narrow main lobe & small side lobes.

Signals received from side lobes can be significantly attenuated.

Uses a linear RF network called Fixed Beam-forming network that combines M antenna elements to form up-to M directional beams.

Why we need to form all the beams

?

Dynamically phased array :

 Consists of either a number of fixed beams with one beam turned on towards the desired signal or a single beam (formed by phase adjustment only) that is steered toward the desired

signal.

Dynamically phased array :

A Direction of arrival algorithm(DoA) tracks the user’s signal as he roams within the range of that beam that is tracking him

Generalization of switched beam concept where received power is maximized.

More efficient than Switched beam system

What is DoA?

The goal of direction-of-arrival (DoA) estimation is to use the data received on the downlink at the base-station sensor array

to estimate the directions of the signals from the desired mobile users as well as the directions of interference signals.

Types of Dynamically phased array

Time domain beamformers: Delays the incoming signal from each array element by a certain

amount of time & then adds them.

Frequency domain beamformers:

Different frequencies are separated. Applying different sum & delay to each frequency it is possible to point out the main lobe.

Comparison between Switched lobe & Phased

array

Comparison between Switched lobe & Phased

array

Adaptive ArrayReducing output noise and enhancing the detection of desired signals.

Array of antenna element.

Real-time adaptive receiver- processor

Types of Adaptive Array Processing

TDMA addaptive array processing

CDMA addaptive array processing

TDMA Adaptive Array Processing

Reverse link configuration for a TDMA systemForward link configuration for a TDMA system

CDMA Adaptive Array Processing

Reverse link configuration for a CDMA system.Forward link configuration for a CDMA system.

Comparison between Switched lobe, Phased array

& Adaptive Array

Application

Mobile Communication

GSM

CDMAWireless CommunicationAerospace Application.IS-136SDMAEDGE

Mobile Communication

Improved services.

Advanced mobile phone system(AMPS).

Advanced TDMA.

User friendly services.

GSM(Global system for Mobile Communication)

Mainly used in the base station.Full beam adaptation in uplink & downlink.Bit rate of 1%Carrier interference of -14 db.

CDMA

Features Diversity Cellular Antennas with 800/1900 MHz bands High accuracy GPS receiver Supports UART and/or USB interfaces

Benefits Designed for easy internal integration no need of SIM card Provides integrators with a network pre-approved communication device Fleet Management and diagnostics In-dash Internet access General Automotive Aftermarket

Wireless Communication

Over come the limitations of omni-directional antenna.

Secterized antenna and coverage pattern.

Aerospace Application

Smart antenna adapts the electromagnetic condition.

Increase of antenna gain

Airborne satellite communication.

Reliable source of communication.

SDMA Spatial Division Multiple Access

Uses an array of antennas to

provide control of space

Network planning (frequency) is

simpler

More network management upgrade required

TDMA with 3 users per channel

162 symbols/slot

14 symbol synchronization sequence

Two receive antennas at base

IS-136

Smart antennas in 3rd generation systems: EDGE High data rate ( 384 kbps) service based on GSM, for

both Europe and North America

BPSK at 270.833 kbps

26 symbol training sequence

576.92 s

58 5826 8.2533

Both phased and adaptive arrays provide increased power by providing higher gain for the desired signal.

In terms of interference suppression, phased arrays reduce the probability of interference with the narrower beam, and adaptive arrays adjust the beam pattern to suppress interference.

Advantages of smart antenna

Conclusion

The use of smart antennas is not purely a radio transmission issue.

It also influences network services such as handover and connection setup.

A smart antenna is a digital wireless communications antenna system that takes advantage of diversity effect at the source (transmitter), the destination (receiver), or both.

Reference

G. K. Chan, “Effects of Sectorization the Spectrum Efficiency of Cellular Radio systems,” Transaction on Vehicular Technology, pp.217-225, vol.41, no.3, Aug 1992.

M. G. Jansen, R. Prasad, “Capacity, Throughput, and Delay Analysis of a Cellular DS CDMA System with Imperfect Power Control and Imperfect Sectorization,” Transaction on Vehicular Technology, pp.67-75, vol.44, no.1, Feb 1995.

X. Yang, S. Ghaheriand N. R. Tafazolli, “Sectorization Gain in CDMA Cellular Systems,” First Conference on 3G Mobile Communication Technologies, pp.70-75, 2000.

Thank you