14-07-2012, 11:45 AM
Multicarrier Communications
[attachment=27623]
Technical Challenges
Hardware
Small, lightweight, low power, multimode operation
Communication Link Design
Channel characterization
Fast, robust, spectrally efficient communication techniques
Mitigation of wireless channel impairments
Multiple Access and Resource Allocation
Efficient modulation, coding and smart antenna schemes that maximize system capacity
Protocols and cross layer optimization
Spectrum Regulation
Spectral Allocation in US controlled by FCC (commercial) or OSM (defense)
FCC allocates spectral blocks for particular applications.
FCC previously gave away spectrum
Currently holds spectral auctions
Some spectrum set aside for universal use
Worldwide spectrum controlled by ITU-R
Standards
Interacting communication systems require standardization
Standards determined by TIA/CTIA in US
IEEE standards often adopted
Worldwide standards determined by ITU-T
In Europe, ETSI is equivalent of IEEE for standards development.
Digital Audio Broadcast
DAB supersedes AM/FM
Main advantage, more channels per BW
6 stereo (12 mono) channels per single freq, allows tranmission of data (as well as programming information)
DAB uses single frequency network, differential quadrature phase shift keying (DQPSK), of BW 1.54 MHz
[attachment=27623]
Technical Challenges
Hardware
Small, lightweight, low power, multimode operation
Communication Link Design
Channel characterization
Fast, robust, spectrally efficient communication techniques
Mitigation of wireless channel impairments
Multiple Access and Resource Allocation
Efficient modulation, coding and smart antenna schemes that maximize system capacity
Protocols and cross layer optimization
Spectrum Regulation
Spectral Allocation in US controlled by FCC (commercial) or OSM (defense)
FCC allocates spectral blocks for particular applications.
FCC previously gave away spectrum
Currently holds spectral auctions
Some spectrum set aside for universal use
Worldwide spectrum controlled by ITU-R
Standards
Interacting communication systems require standardization
Standards determined by TIA/CTIA in US
IEEE standards often adopted
Worldwide standards determined by ITU-T
In Europe, ETSI is equivalent of IEEE for standards development.
Digital Audio Broadcast
DAB supersedes AM/FM
Main advantage, more channels per BW
6 stereo (12 mono) channels per single freq, allows tranmission of data (as well as programming information)
DAB uses single frequency network, differential quadrature phase shift keying (DQPSK), of BW 1.54 MHz