05541955 is referenced by 289 patents and cites 19 patents.

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. Incoming and outgoing data are buffered, and the transmission rate is changed dynamically by a memory controller (109) to avert buffer overflows and underflows. An optional adaptive phase-lock loop system (116) maintains synchronization of the decoder at all data rates.

Title
Adaptive data rate modem
Application Number
973816
Publication Number
5541955
Application Date
April 28, 1995
Publication Date
July 30, 1996
Inventor
Jay M Jacobsmeyer
Colorado Springs
CO, US
Agent
Fish & Richardson P C
Assignee
Pericle Communications Company
CO, US
IPC
H04B 1/38
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