Comparison of OFDM and Single-Carrier Transmission for Ultra-Low Delay Applications
- Resource Type
- Authors
- Wolfgang H. Gerstacker; Christoph Rachinger; Johannes B. Huber
- Source
- GLOBECOM Workshops
- Subject
- Equalization
Computer science
Orthogonal frequency-division multiplexing
ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS
020206 networking & telecommunications
Data_CODINGANDINFORMATIONTHEORY
02 engineering and technology
Long code
Intersymbol interference
Transmission (telecommunications)
0202 electrical engineering, electronic engineering, information engineering
Electronic engineering
Bit error rate
Code (cryptography)
Decoding methods
Communication channel
Phase-shift keying
- Language
In this paper, we show that Orthogonal Frequency Division Multiplexing (OFDM) is not well suited for transmission over wireless channels with intersymbol interference (ISI), if a low delay constraint prohibits the use of channel codes with long code words. We compare OFDM with single-carrier transmission for scenarios with very short block lengths and different code rates. The single-carrier receive signal is equalized and decoded using either a Turbo scheme or a so-called matched decoder, which combines channel equalization and decoding and allows for a flexible trade-off between complexity and performance. Our results show that OFDM suffers from severe losses compared to single-carrier transmission if a very low latency—corresponding to a very short block length—is required. This effect is most pronounced for high code rates.