Title: EE 609 :TERM PAPER
1EE 609 TERM PAPER
Presented by - RITESH PAL BINAY RAJ
2Overview
Part I
- Introduction
- Types of Smart antennas
- Smart antenna for vehicles
Part II
- Beamforming algorithms
- DoA algorithms
- MSA implementation
3Smart Antenna
- Smart antenna refers to a system of antenna
array with smart signal processing algorithms
that are used to identify spatial signal
signature such as the DOA of the signal, and use
it to calculate beam forming vectors, to track
and locate the antenna beam on the mobile/target.
4SA Application
- Radar
- Radio Astronomy
- Radio Telescopy
- Cellular System
5Non Smart antenna system
- Limited BW available hence interference in
system - Omni directional antennas used at the BS
- This is an interference limited system
- Solution Sectorized antenna
Source http//www.altera.com/endmarket/wirelessant
enna
6Smart antenna Technology
BS
- Concept of beam forming
- Reduces interferences in the system increases
capacity - Each user signal is multiplied by complex weight
thereby - adjusting mag phase of signal beam is
formed - Beam forming is of two types
Source http//www.altera.com/endmarket/wirelessant
enna
7Switched beam
- Beams are formed in pre determined direction
- BS switches between different beams based on Rx
signal measurement.
Source http//www.smartanteenas.googlepages.com
8Adaptive beam forming
- Beams are not formed in pre determined
direction - Real time processing
- BS forms narrow beam towards desired user
- Improves S/N ratio
Source http//www.altera.com/endmarket/wirelessant
enna
9Types of SA
10MIMO
Advantages
- Increased data handling capability
- Higher spectral efficiency
- No additional BW requirement
Source www.webopedia.com
11Adaptive arrays antennas
- Switched beam
- Parasitic array
- Digital beam forming array
- Diversity array
- Phased array
12Switched beam forming implementation
- Implementation using power splitters phase
shifters - Application Radar, EW satellite system
Source http//www.smartanteenas.googlepages.com
13Phased array antenna
Functional block diagram of phased array mounted
on car
Source http//www.smartanteenas.googlepages.com
14Phased array antenna
Functional diagram of phased array antenna
15Digital beam forming array antenna
.
Source http//www.smartanteenas.googlepages.com
16Parasitic array antenna
- Active element is surrounded by number of
parasitic elements - Switching of parasitic elements done by PIN
diode - 3 direction beam steering achieved
17SA application on vehicles with array antenna
Cellular car radio antenna 1
- Antennas are usually vertically mounted
- Requirement Omni directional pattern in azimuth
plane
18Radiation properties as function of antenna
location
Radiation properties as a function of antenna loc
on car2
- Roof rim has rotational non symmetric
environment - Deviation of desired omni directional pattern
- Omni directional pattern could be achieved only
at - the center of roof
19Array antenna on vehicles1
- Multi element phased array technique
- Vertical dimension less than quarter wavelength
is possible - At BS individual BF for individual tracking
signal optimzation - Conventional methods used at Mobile station
- Thus only one RX/TX front end is required
203 element antenna with adjustable main beam
direction1
- Achievement Adjustable directive main beam
covering - complete azimuth plane
- Reduction in side lobes
- Gain is 5 dB more than conventional antenna
- Further optimization possible by 4 elements
21Two element optimized antenna
2 element pattern optimized antenna 2
22Diversity car antenna for cellular radio
Signal quality with different antenna
combination1
- Problem of multiple path propagation in channel
- Signal quality improves with number of elements
23Part II
24Why Smart Antennas ?
- Enhance System performance
- Increases channel capacity
- Enhances Spectrum efficiency
- Range coverage
- Track multiple users
- Reduce Interference
- Delay spread
- Multipath fading
25Why Smart Antennas ? (contd..)
- Reduce system complexity
- Reduce co channel interference
- Tx mode
- Rx mode
26Terminologies
- Fading
- Mean path loss
- Slow fading
- Difficult to predict
- Fast fading
- Multipath propagation
- Phase variations
- Rayleigh distribution
- Channel spread
- Doppler spread
- Angle spread
- Delay spread
27Switched Beam Vs Adaptive Array
28Block diagram of Smart Antenna
Source 8
29Beamforming
30Beamforming Schemes
- Delay sum
- Unity response
- Disadvantage Interference
- Null steering
- Cancels plane wave from known direction
- Handles strong interference
- Disadvantage Multiple interference
- Digital Beamforming
- Higher sampling rates
- Capacity enhancement upto 200
Source 4
31Adaptive Beamforming Algorithms
- Sample Matrix Inversion (SMI)
- Replaces covariance matrix of spatially sampled
signals by estimated value iteratively - Least Mean Square (LMS)
- Weights are subjected to constraints
- Constant Modulus Algorithm (CMA)
- Assumes that interference causes amplitude
fluctuation in o/p - Neural Network approach
- Applicable when ref sig is available
- Iteratively minimizes the MSE between ref sig and
modified array o/p
Source 5
32DoA Algorithms
- DFT and Maximum Entropy Method (MEM)
- Uses signal subspace
- MUltiple SIgnal Classification (MUSIC)
- Estimates DoA in noise subspace
- More accurate
Source 8
33Smart Antenna Design Implementation
A planar array configuration Dx 54.562 mm, Dy
54.747 mm, dx 7.500 mm, dy 7.500 mm, xo
0.794 mm, yo 1.164 mm, W 2.247 mm, L 2.062
mm, t 0.300mm, ?r 11.7, ? 0.04, f
20GHz.
Source 6
34Radiation Pattern
E-plane
H-plane
Source 6
35Conclusion
- Advantages accrued
- Applications
- PL
- Adhoc networks
- High data rate 3G
- Applicable scheme for
- TDMA
- CDMA
36References
- 1 R Kronberger,H Lindermerier,J Hopf Smart
antenna applications on vehicles - with low profile array antenna Proc IEEE Vol 53
pp1-3 September 2003. - 2 R Kronberger,H Lindermerier,J Hopf Design
method for antenna array on cars Proc IEEE Vol
101 pp11-15 September 2003. - 3 http//www.smartanteenas.googlepages.com
- 4 http//www.iec.org
- 5Michael Chryssomallis Smart antennas IEEE
antenna and propagation magazine Vol 42 No 3 pp
129-138, June 2000. - 6Salvatore Bellofiore, Constantine,Jeffry and
Andreas Smart antenna systems for mobile
communication networks IEEE Antennas and
propagation magazine - Vol 44 No 3 pp 145-154, June 2002.
- 7 AJ Paulraj,D Gesbert Smart antennas for
mobile communication IEEE Antennas and
propagation magazine Vol 57 No 5 pp 1-14, June
2000. - 8JM Samhan,RM Shubair and MA Alquadi Design
and implementation of an adaptive smart antenna
Proc IEEE Vol 57 pp6-7 September 2006.
37Questions ??