5 research outputs found
Lossy Transmission of Correlated Sources over Two-Way Channels
Achievability and converse results for the lossy transmission of correlated
sources over Shannon's two-way channels (TWCs) are presented. A joint
source-channel coding theorem for independent sources and TWCs for which
adaptation cannot enlarge the capacity region is also established. We further
investigate the optimality of scalar coding for TWCs with discrete modulo
additive noise as well as additive white Gaussian noise. Comparing the
distortion of scalar coding with the derived bounds, we observe that scalar
coding achieves the minimum distortion over both families of TWCs for
independent and uniformly distributed sources and independent Gaussian sources.Comment: 5 pages, 3 figures, a minor typo fixed, presented at IEEE ITW 201
Joint Source-Channel Coding for the Transmission of Correlated Sources over Two-Way Channels
A joint source-channel coding (JSCC) scheme based on hybrid digital/analog
coding is proposed for the transmission of correlated sources over
discrete-memoryless two-way channels (DM-TWCs). The scheme utilizes the
correlation between the sources in generating channel inputs, thus enabling the
users to coordinate their transmission to combat channel noise. The hybrid
scheme also subsumes prior coding methods such as rate-one separate
source-channel coding and uncoded schemes for two-way lossy transmission, as
well as the correlation-preserving coding scheme for (almost) lossless
transmission. Moreover, we derive a distortion outer bound for the
source-channel system using a genie-aided argument. A complete JSSC theorem for
a class of correlated sources and DM-TWCs whose capacity region cannot be
enlarged via interactive adaptive coding is also established. Examples that
illustrate the theorem are given.Comment: a spelling error correcte
Capacity of Generalized Discrete-Memoryless Push-to-Talk Two-Way Channels
In this report, we generalize Shannon's push-to-talk two-way channel
(PTT-TWC) by allowing reliable full-duplex transmission as well as noisy
reception in the half-duplex (PTT) mode. Viewing a PTT-TWC as two
state-dependent one-way channels, we introduce a channel symmetry property
pertaining to the one-way channels. Shannon's TWC capacity inner bound is shown
to be tight for the generalized model under this symmetry property. We also
analytically derive the capacity region, which is shown to be the convex hull
of (at most) 4 rate pairs. Examples that illustrate different shapes of the
capacity region are given, and efficient transmission schemes are discussed via
the examples.Comment: 10 pages, 5 figures, 5 tables, a typo corrected, presented at CWIT'1
Scalar Quantizer Design for Two-Way Channels
The problem of lossy transmission of correlated sources over memoryless
two-way channels (TWCs) is considered. The objective is to develop a robust low
delay and low complexity source-channel coding scheme without using error
correction. A simple full-duplex channel optimized scalar quantization (COSQ)
scheme that implicitly mitigates TWC interference is designed. Numerical
results for sending Gaussian bivariate sources over binary additive-noise TWCs
with either additive or multiplicative user interference show that, in terms of
signal-to-distortion ratio performance, the proposed full-duplex COSQ scheme
compares favourably with half-duplex COSQ.Comment: the manuscript upload on arXiv is an updated version of the one
published in the CWIT'2019 Proceeding
Two-Way Source-Channel Coding
We propose an adaptive lossy joint source-channel coding (JSCC) scheme for
sending correlated sources over two-terminal discrete-memoryless two-way
channels (DM-TWCs). The main idea is to couple the independent operations of
the terminals via an adaptive coding mechanism, which can mitigate
cross-interference resulting from simultaneous channel transmissions and
concurrently exploit the sources' correlation to reduce the end-to-end
reconstruction distortions. Our adaptive JSCC scheme not only subsumes existing
lossy coding methods for two-way simultaneous communication but also improves
their performance. Furthermore, we derive outer bounds for our two-way lossy
transmission problem and establish complete JSCC theorems in some special
settings. In these special cases, a non-adaptive separate source-channel coding
(SSCC) scheme achieves the optimal performance, thus simplifying the design of
the source-channel communication system.Comment: 44 pages, 6 figure