B. P. Lathi, Zhi Ding - Modern Digital and Analog Communication Systems-Oxford University Press (2009)

710 DIGITAL COMMUNICATIONS UNDER LINEARLY DISTORTIVE CHANNELS
TABLE 12.3
A Short but Impressive History of OFDM Applications
Year
Events
1995 Digital audio broadcasting standard Eureka 147: first OFDM standard
1996 ADSL standard ANSI Tl.413 (later became ITU G.992.1)
1997 DVB-T standard defined by ETSI
1998 Magic WAND project demonstrates OFDM modems for wireless LAN
1999 IEEE 802.lla wireless LAN standard (Wi-Fi)
2002 IEEE 802. llg standard for wireless LAN
2004 IEEE 802.16d standard for wireless MAN (WiMAX)
2004 MediaFLO announced by Qualcomm
2004 ETSI DVB-H standard
2004 Candidate for IEEE 802.15.3a (UWB) standard MB-OFDM
2004 Candidate for IEEE 802.lln standard for next-generation wireless LAN
2005 IEEE 802.16e (improved) standard for WiMAX
2005 Terrestrial DMB (T-DMB) standard (TS 102 427) adopted by ETSI (July)
2005 First T-DMB broadcast began in South Korea (December)
2005 Candidate for 3.75G mobile cellular standards (LTE and HSOPA)
2005 Candidate for CJK (China, Japan, Korea) 4G standard collaboration
2005 Candidate for IEEE P1675 standard for power line communications
2006 Candidate for IEEE 802.16m mobile WiMAX
companies before completing their merger in 2008. The new company, Sirius XM, serves
satellite car radios, while IBOC targets traditional home radio customers. Sirius XM uses the
2.3 GHz S-band for direct satellite broadcasting. Under the commercial name of HD Radio
developed by iBiquity Digital Corporation, IBOC allows analog FM and AM stations to use
the same band to broadcast their content digitally by exploiting the gap between traditional
AM and FM radio stations. By October 2008, over 1.5 million HD radio chipsets have been
shipped and there were more than 1800 HD Radio Stations in the United States alone.
In satellite radio operation, XM radio uses the bandwidth of 2332.5 to 2345.0 MHz.
This 12.5 MHz band is split into six carriers. Four carriers are used for satellite transmission.
XM radio uses two geostationary satellites to transmit identical program content. The
signals are transmitted with QPSK modulation from each satellite. For reliable reception, the
line-of-sight signals transmitted from satellite 1 are received, reformatted to multicarrier modulation
(OFDM), and rebroadcast by terrestrial repeaters. Each two-carrier group broadcasts
100 streams of 8 kbit/s. These streams represent compressed audio data. They are combined by
means of a patented process to form a variable number of channels using a variety of bit rates.
Sirius satellite radio, on the other hand, uses three orbiting satellites over the frequency
band of 2320 to 2332 MHz. These satellite are in lower orbit and are not geostationary. In fact,
they follow a highly inclined elliptical Earth orbit (HEO), also known as the Tundra orbit. Each
satellite completes one orbit in 24 hours and is therefore said to be geosynchronous. At any
given time, two of the three satellites will cover North America. Thus, the 12 MHz bandwidth
is equally divided among three carriers: two for the two satellites in coverage and one for
terrestrial repeaters. The highly reliable QPSK modulation is adopted for Sirius transmission.
Terrestrial repeaters are useful in some urban areas where satellite coverage may be blocked.
For terrestrial HD radio systems, OFDM is also key modulation technology in IBOC
for both AM IBOC and the FM IBOC. Unlike satellite DAB, which bundles multiple station
programs into a single data stream, AM IBOC and FM IBOC allow each station to use its
own spectral allocation to broadcast, just like a traditional radio station. FM IBOC has broader