multi carrier modulation and single carrier modulation
DESCRIPTION
A brief comparison of multicarrier modulation and Single carrier ModulationTRANSCRIPT
Multi Carrier vs. Single Carrier Copyright 2012 Fernando
Ramirez-Mireles [email protected], [email protected]
1
Fernando Ramirez-Mireles, [email protected], [email protected]
MultiCarrier vs
Single Carrier
Multi Carrier vs. Single Carrier Copyright 2012 Fernando
Ramirez-Mireles [email protected], [email protected]
2
MultiCarrier (Discrete Multi Tone DMT) and Single Carrier Modulation (SCM)
Signal PSD (dBm/Hz)
Frequency
(MHZ)
freq.1
freq.2
freq.3
freq.4
freq.5
US1 DS1 US2 DS2 US3
Signal PSD (dBm/Hz)
Frequency
(MHZ)
freq.1
freq.2
freq.3
freq.4
freq.5
US1 DS1 US2 DS2 US3
DISCRETE MULTI TONE (Divide and Conquer) SINGLE CARRIER MODULATION
Mr. FEC
Multi Carrier vs. Single Carrier Copyright 2012 Fernando
Ramirez-Mireles [email protected], [email protected]
3
Multicarrier (DMT) Processing
Multi Carrier vs. Single Carrier Copyright 2012 Fernando
Ramirez-Mireles [email protected], [email protected]
4
SCM Processing
Multi Carrier vs. Single Carrier Copyright 2012 Fernando
Ramirez-Mireles [email protected], [email protected]
5
Comparing Multicarrier (DMT) and SCM
Issues Deleterious effects
DMT solution SCM solution Advantages of DMT over SCM
Channel Time Dispersion
Signal Smearing
Equalization: Two simple equalizers, one in time domain and one in frequency domain
Equalization: One complicated equalizer in time domain
Simplicity in design and implementation
Frequency dependent Noise
Frequency dependent signal-to-noise ratio (SNR)
Bit loading: Transmit more bits in frequency bands where there is less noise and less bits in frequency bands where there is more noise
No bit loading: Transmit the same average number of bits in every frequency band regardless of amount of noise in each frequency band
Bandwidth efficiency and higher throughput
FDD full duplex operation in multi-band spectrum plans
Interference between upstream and downstream signals
Signal separation: Use no filtering, utilize Fourier Transform orthogonality properties
Signal separation: Use one complicated filter per transmission band
Higher spectrum utilization, higher throughput and flexible implementation of different band plans
Multi Carrier vs. Single Carrier Copyright 2012 Fernando
Ramirez-Mireles [email protected], [email protected]
6
FERNANDO RAMIREZ-MIRELES
Multi Carrier vs. Single Carrier Copyright 2012 Fernando
Ramirez-Mireles [email protected], [email protected]
7
About the author
Fernando has over 10 years of experience in R&D in VDSL, UWB and speech processing. He has worked in the DSL field as a systems and algorithms engineer. He is currently a professor in the engineering division at ITAM in Mexico City. He has authored more than twenty technical articles and has one patent granted and two more pending. He is a senior member of the IEEE. He can be reached at [email protected].