Two–Way Relaying Communications with OFDM and BICM/BICM-ID
Date
2016-05-16
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
Type
Degree Level
Doctoral
Abstract
Relay-aided communication methods have gained strong interests in academic community
and been applied in various wireless communication scenarios. Among different techniques
in relay-aided communication system, two-way relaying communication (TWRC) achieves
the highest spectral efficiency due to its bi-directional transmission capability. Nevertheless,
different from the conventional point-to-point communication system, TWRC suffers from
detection quality degradation caused by the multiple-access interference (MAI). In addition,
because of the propagation characteristics of wireless channels, fading and multipath
dispersion also contribute strongly to detection errors. Therefore, this thesis is mainly concerned
with designing transmission and detection schemes to provide good detection quality
of TWRC while taking into account the negative impacts of fading, multipath dispersion
and multiple-access interference.
First, a TWRC system operating over multipath fading channels is considered and orthogonal
frequency-division multiplexing (OFDM) is adopted to handle the inter-symbol
interference (ISI) caused by the multipath dispersion. In particular, adaptive physical-layer
network coding (PNC) is employed to address the MAI issue. By analyzing the detection
error probability, various adaptive PNC schemes are discussed for using with OFDM and
the scheme achieving the best trade-off among performance, overhead and complexity is
suggested.
In the second part of the thesis, the design of distributed precoding in TWRC using
OFDM under multipath fading channels is studied. The objective is to design a distributed
precoding scheme which can alleviate MAI and achieve multipath diversity to combat fading.
Specifically, three types of errors are introduced when analyzing the error probability in the
multiple access (MA) phase. Through analysis and simulation, the scheme that performs
precoding in both time and frequency domains is demonstrated to achieve the maximum
diversity gains under all types of errors.
Finally, the last part of the thesis examines a communication system incorporating forward
error correction (FEC) codes. Specifically, bit-interleaved code modulation (BICM)
without and with iterative decoding (BICM-ID) are investigated in a TWRC system. Distributed
linear constellation precoding (DLCP) is applied to handle MAI and the design
of DLCP in a TWRC system using BICM/BICM-ID is discussed. Taking into account the
multiple access channel from the terminal nodes to the relay node, decoding based on the
quaternary code representation is introduced. Several error probability bounds are derived
to aid in the design of DLCP. Based on these bounds, optimal parameters of DLCP are
obtained through analysis and computer search. It is also found that, by combining XORbased
network coding with successful iterative decoding, the MAI is eliminated and thus
DLCP is not required in a BICM-ID system.
Description
Keywords
Two-way relaying, Multiple access, OFDM, BICM, BICM-ID, cooperative, distributed precoding, physical-layer network coding, quaternary decoding
Citation
Degree
Doctor of Philosophy (Ph.D.)
Department
Electrical and Computer Engineering
Program
Electrical Engineering