US 4,063,038 A · Error coding communication terminal interface

Abstract

A communication terminal interface accepts, on different channels, information in a plurality of formats for communication purposes over a communication link which may be a TDMA satellite link. Each channel is accepted by a different interface unit which serves to format the information for communication over the system. This unit includes a compression-expansion buffer memory for allowing information received at a receive rate R.sub.s to be multiplexed and transmitted at a transmission rate T.sub.s which may be many times higher than the receive rate. In addition some units may include forward acting error correcting coding selected to provide the necessary corrected bit error rate for the type of information accepted by the unit and the capacity of the communication link over which the information is to be transmitted. The transmitter may employ differential encoding. To avoid increasing the error rate, which would normally result from this type of encoding, the encoded data is interleaved at the transmit side such that adjacent errors, after de-interleaving, on the receive side, are sufficiently displaced such that they may be corrected by the error decoding.

Claims12

Dependent claims

Apparatus for interfacing a plurality of terrestrial communication links to a TDMA communication system including a remote transponder, comprising:

a plurality of interface modules, each including a compression/expansion memory means for increasing the nominal clock rate of data flowing from one of said terrestrial links toward the transponder and for decreasing the nominal clock rate of data flowing from the transponder toward one of said terrestrial links, each of said memory means thus establishing low speed data on one side adjacent one of said terrestrial links and a higher speed data on the side opposite to said one side,
selected ones of said modules further including forward acting error correcting coding/decoding means connected to said memory means on the terrestrial side thereof,
said compression/expansion memory means including a separate compression memory and a separate expansion memory.
said compression memory including a pair of memories each of which includes a pair of memory banks,
said expansion memory including a pair of memories, each of said memories including a pair of memory banks,
address control means for each of said compression memory banks to control writing data into said compression memory banks in sequential order and to control reading from said compression memory banks in interleaved fashion.

3 more elements

Dependencies are inferred from the claim text.

Error coding communication terminal interface

Life of this patent

Error coding communication terminal interface

Life of this patent

Abstract

Claims12