TY - JOUR
T1 - The Capacity Region of the Symbol-Asynchronous Gaussian Multiple-Access Channel
AU - Verdú, Sergio
N1 - Funding Information:
Manuscript received June 6, 1987; revised October 10,1988. This work was supported in part by the Office of Naval Research under Contract N00014-87-K-0054. This paper was presented in part at the IEEE International Symposium on Information Theory, Ann Arbor, MI, October 1986, and in part at the IEEE Workshop on Information Theory, Bella- gio, Italy, June, 1987.
PY - 1989/7
Y1 - 1989/7
N2 - In the information theory of the multiple-access channel, two types of synchronism are usually assumed among the transmitters, namely, frame and symbol synchronism. Frame synchronism refers to the ability of the users to start the transmission of their codewords in unison. The issue of symbol synchronism arises in continuous-time channels in which each codeword symbol modulates a fixed assigned waveform; the channel is symbol synchronous if the users cooperate so that their symbol epochs coincide at the receiver. In practice symbol synchronism is harder to achieve, yet the only reported progress so far has been in the removal of the assumption of frame synchronism. It is shown that if the transmitters are assigned the same waveform, symbol asynchronism has no effect on the two-user capacity region of the white Gaussian channel which is equal to the Cover-Wyner pentagon, whereas if the assigned waveforms are different (e.g., code division multiple access), the symbol-asynchronous capacity region is no longer a pentagon.
AB - In the information theory of the multiple-access channel, two types of synchronism are usually assumed among the transmitters, namely, frame and symbol synchronism. Frame synchronism refers to the ability of the users to start the transmission of their codewords in unison. The issue of symbol synchronism arises in continuous-time channels in which each codeword symbol modulates a fixed assigned waveform; the channel is symbol synchronous if the users cooperate so that their symbol epochs coincide at the receiver. In practice symbol synchronism is harder to achieve, yet the only reported progress so far has been in the removal of the assumption of frame synchronism. It is shown that if the transmitters are assigned the same waveform, symbol asynchronism has no effect on the two-user capacity region of the white Gaussian channel which is equal to the Cover-Wyner pentagon, whereas if the assigned waveforms are different (e.g., code division multiple access), the symbol-asynchronous capacity region is no longer a pentagon.
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U2 - 10.1109/18.32152
DO - 10.1109/18.32152
M3 - Article
AN - SCOPUS:0024705423
SN - 0018-9448
VL - 35
SP - 733
EP - 751
JO - IRE Professional Group on Information Theory
JF - IRE Professional Group on Information Theory
IS - 4
ER -