SDR for mobile communication

M . R . AzimiCourse seminar for SDR

Instructor : Dr Omidi

Modern communication : wireless voice serviceLeading edge of this revolution : GSM

Simultaneous phenomenon : InternetLeading edge of this phenomenon : www ,web browser,

TCP/IP

New idea : integrate both of themthird generation

Common methods for providing BWMHSCSD : symmetric or asymmetric aggregates circuit

channels

GPRS: sharing time slots between different users and enabling Internet access

EDGE modifies the radio link modulation from GMSK to 8QPSK

UMTS utilizes a wide band CDMA or TD/CDMA transceiver

UMTSAll mentioned methods using circuit switching: - inefficient for bursty traffic - scheduler at RNC , slow resource allocation -slow update for SHO during cell selection.

UMTS New approach : using packet switching , adding all IP

features , HSDPA, intelligent or adaptive antenna - a spectrum efficient packet-by-packet fast scheduling- Fast Resource Allocation with the scheduler at the BTS- FCS due to the optimization for packet data delivery, capacity

coverage and high data rate at the cell edge

RF system design Noise and channel capacity :

Free space loss :

Loss in non L.O.S :

Outdoor to indoor and pedestrian model :

RF system designReceiving power in two models: - left figure : -right figure: for point B: for point D:

A/D , D/AFirst nyquist rule , BP sampling , over samplingAnti aliasing filter : SAW filtersuccessive approximation, multipass architecture ,ditheringclock jitter and aperture uncertainty - ADC with an rms sample clock timing jitter of

ADC noise budget :

DAC noise budget:

DUCs , DDCsDDC’s requirements in 2G and 3G:-Filter or isolate a narrow band of frequencies from the

wideband source and reject the reminder of the band.-Translate that isolated carrier down in frequency ,usually from

an IF to baseband.-Reduce the data rate to some integer multiple of information

rate.DUC’s requirements in 2G and 3G:-translate one or more narrowband signal sources up in

frequency, usually from baseband to an IF.-Combine the baseband sources to create one wideband result.-Increase the data rate to a digital IF rate.

ISL5217(DUC)Data input routing Data modulation Sample rate NCO Shaping filters Halfband filter Complex mixer and carrier NCO Gain control Output routing, summing and control

CDMA fundamentals Spreading

Multiple access

soft handoff

power control

RAKE receiver

Macro cell specificationsMacro cells : high reliability and providing fall-back

capacity

Micro cell specificationsHigh user density , lower power RF power amplifier

References:software defined radio for 3G “ Paul burns “The UMTS Network and Radio Access Technology “Dr.

Jonathan P. Castro “Orange Communications SA/AG, Switzerland

“Communication Profiles for SDR Equipment” by Eiman Mohyeldin, Markus Dillinger, and J. Luo, Peter Dornbusch, Michael Fahrmair, Chris Salzmann, Siemens AG, Munich University of Technology

Software radio evolution and its application to aeronautical mobile communications by ”Minh Nguyan”

Software Defined Radio Forum General Meeting by Nalini Uhrig , Bryan Tropper, Nancy Pearson, Michael Agha