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Feedback Communication Using Orthogonal Signals


Lavenberg, Stephen Stuart (1968) Feedback Communication Using Orthogonal Signals. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/WKWH-7823.


This research is concerned with block coding for a feedback communication system in which the forward and feedback channels are independently disturbed by additive white Gaussian noise and average power constrained. Two coding schemes are proposed in which the messages to be coded for transmission over the forward channel are realized as a set of orthogonal waveforms. A finite number of forward and feedback transmissions (iterations) per message is made. Information received over the feedback channel is used to modify the waveform transmitted on successive forward iterations in such a way that the expected value of forward signal energy is zero on all iterations after the first. Similarly, information is sent over the feedback channel in such a way that the expected value of feedback signal energy is also zero on all iterations after the first. These schemes are shown to achieve a lower probability of error than the best one-way coding scheme at all rates up to the forward channel capacity, provided only that the feedback channel capacity be greater than the forward channel capacity. These schemes make more efficient use of the available feedback power than existing feedback coding schemes, and therefore require less feedback power to achieve a given error performance.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Electrical Engineering)
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Electrical Engineering
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Grettenberg, Thomas L.
Thesis Committee:
  • Unknown, Unknown
Defense Date:26 April 1968
Record Number:CaltechTHESIS:12212015-093040606
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:9336
Deposited On:21 Dec 2015 17:51
Last Modified:02 Apr 2024 23:18

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