Jay M Jacobsmeyer
Engineers in Colorado Springs, CO
License number
Colorado 28768
Issued Date
Feb 5, 1993
Renew Date
Nov 1, 2015
Expiration Date
Oct 31, 2017
Type
Professional Engineer
Address
Address
PO Box 50378, Colorado Springs, CO 80949
Professional information
Adaptive Data Rate Modem
US Patent:
5541955, Jul 30, 1996
Filed:
Apr 28, 1995
Appl. No.:
8/430268
Inventors:
Jay M. Jacobsmeyer - Colorado Springs CO
Assignee:
Pericle Communications Company - Colorado Springs CO
International Classification:
H04B 138
US Classification:
375222
Abstract:
An adaptive data rate modulator/demodulator (modem) (102), particularly useful for transmitting data over fading communications channels, uses an adaptive data rate technique which supports multiple data rates in the same device. The modem incorporates an adaptive data rate encoder (104) and an adaptive data rate decoder (105) using adaptive, parallel-branch decoding to translate received symbols into corresponding data bits. Significantly, the soft decision metrics of the decoder are also used to provide an estimate W of the signal-to-noise ratio. An optional predictor (232) receives W from the adaptive data rate decoder (105) and predicts the future signal-to-noise ratio to determine the desired data rate for the modem. The data rate is changed automatically and dynamically without interrupting the decoding process. A constant channel symbol rate and a single signal set simplify signal acquisition and synchronization.