A seminar on Satellite Radio by Sagar Medikeri, April 2010.

1. Satellite Radio – a technological overview Sagar Medikeri, 2BV06EC060

2. Radio – Analog and Digital Introduction to Satellite Radio Various Satellite Radio Technologies Future of Satellite Radio Seminar Overview

4. Analog vs. Digital Radio

5. Satellite Radio - Market Players

6. Large area coverage CD quality audio Subscription based Commercial-free content Lots of variety - 100s of channels Programming includes music, news, talk radio, sports, humor Audio associated metadata transmitted Some channels broadcast in 5.1 surround sound format FCC does not regulate content Service features

7. How Satellite Radio works? Uplink Station, Satellite & Terrestrial Repeaters Control Room Terrestrial Repeaters Fixed Receivers

8. Satellite Technology

9. 1worldspace satellite spot beams Asiastar Afristar

10. ATIS (Automatic Transmission Identification Service). In this scheme, there can be multiple uplink facilities. Each uplink facility has a station ID. 2 or 3 Parabolic or Unfurlable Antennas are used The RF signal received by satellites is amplified by high power TWTAs operating in parallel RF power transmitted is 12 – 15 KW Satellites’ lifetime is 12 - 15 years Satellite Technology

11. Receiver Technology 2320 MHz 2332.5 MHz Carrier 1 Carrier 2 Carrier 3 4 MHz 4 MHz 4 MHz

12. Receiver Technology Sirius 1 Carrier 1 Carrier 1 Sirius 2 Carrier 2 Carrier 3 75 MHz IF ~ -50dBm Maximal-Ratio Combining for Signal Diversity Baseband Processor Antenna Tuner 2.3 GHz Digitize, Demodulate, Error correction, Decrypt Down conversion

13. Maximal Ratio Combining Adder Baseband 1 a1 Retrieve the 3 Baseband signals 75 MHz IF Baseband 2 a2 Best estimate of Baseband signal Baseband 3 a3

14. Perceptual Audio Coding Entropy Coding Filter Banks Quantization & Encoding MUX Audio Compressed Audio Psychoacoustic Model Bit Allocation

15. Achieved by Hierarchical Modulation QPSK is embedded into 16QAM QPSK carries “High Priority” bits & QAM carries “Less Priority” bits In poor link conditions, at least QPSK is resolved Economizes Bandwidth Link Adaptation

16. Used to limit reception to legitimate subscribers Integrity of content Content Protection Elliptical Curve Cryptography (ECC) is used for encryption. ECC provides RSA level security with a smaller key. This reduces transmission overhead. Conditional Access

17. Receivers ($120) and Subscriptions (>$7/month) costly Stiff competition from iPod, Internet Radio, local FM Steady Attrition Rates Sirius & XM still in debt But, the technology developed for Satellite Radio will pave the way for Satellite Digital Media Broadcasting (S-DMB) Future of Satellite Radio

18. Painter, T., and A. Spanias. "Perceptual coding of digital audio." Proceedings of the IEEE 88 (2000) Wikipedia entries on, 1. Sirius Radio 2. XM Radio 3. Psychoacoustics Gledhill J., MacAvock P., Miles R. Whitepaper on “Hierarchical Modulation” References

19. Thank You !!