27 research outputs found
Automatic-repeat-request error control schemes
Error detection incorporated with automatic-repeat-request (ARQ) is widely used for error control in data communication systems. This method of error control is simple and provides high system reliability. If a properly chosen code is used for error detection, virtually error-free data transmission can be attained. Various types of ARQ and hybrid ARQ schemes, and error detection using linear block codes are surveyed
The study of sequential decoding techniques for spacecraft telemetry systems Final report, 12 Jan. - 12 Jun. 1968
Convolutional encoding-sequential decoding technique for coherent deep space telemetry link and near earth space mission
On distributed coding, quantization of channel measurements and faster-than-Nyquist signaling
This dissertation considers three different aspects of modern digital communication
systems and is therefore divided in three parts.
The first part is distributed coding. This part deals with source and source-
channel code design issues for digital communication systems with many transmitters
and one receiver or with one transmitter and one receiver but with side information at
the receiver, which is not available at the transmitter. Such problems are attracting
attention lately, as they constitute a way of extending the classical point-to-point
communication theory to networks. In this first part of this dissertation, novel source
and source-channel codes are designed by converting each of the considered distributed
coding problems into an equivalent classical channel coding or classical source-channel
coding problem. The proposed schemes come very close to the theoretical limits and
thus, are able to exhibit some of the gains predicted by network information theory.
In the other two parts of this dissertation classical point-to-point digital com-
munication systems are considered. The second part is quantization of coded chan-
nel measurements at the receiver. Quantization is a way to limit the accuracy of
continuous-valued measurements so that they can be processed in the digital domain.
Depending on the desired type of processing of the quantized data, different quantizer
design criteria should be used. In this second part of this dissertation, the quantized
received values from the channel are processed by the receiver, which tries to recover
the transmitted information. An exhaustive comparison of several quantization cri-
teria for this case are studied providing illuminating insight for this quantizer design
problem.
The third part of this dissertation is faster-than-Nyquist signaling. The Nyquist
rate in classical point-to-point bandwidth-limited digital communication systems is
considered as the maximum transmission rate or signaling rate and is equal to twice
the bandwidth of the channel. In this last part of the dissertation, we question this
Nyquist rate limitation by transmitting at higher signaling rates through the same
bandwidth. By mitigating the incurred interference due to the faster-than-Nyquist
rates, gains over Nyquist rate systems are obtained
Space programs summary no. 37-64, volume 2 for the period 1 June to 31 July 1970. The Deep Space Network
Mariner Mars 1971 mission support, engineering, and design of Deep Space Networ
Telemetry coding study for the international magnetosphere explorers, mother/daughter and heliocentric missions. Volume 2: Final report
A convolutional coding theory is given for the IME and the Heliocentric spacecraft. The amount of coding gain needed by the mission is determined. Recommendations are given for an encoder/decoder system to provide the gain along with an evaluation of the impact of the system on the space network in terms of costs and complexity
Concatenation of convolutional and block codes Final report
Comparison of concatenated and sequential decoding systems and convolutional code structural propertie