DATA TRANSMISSION INVESTIGATION
Quarterly progress rept. no. 2, 11 Dec 1962-10 Mar 1963
MOTOROLA INC CHICAGO IL
Pagination or Media Count:
The characteristics of the ANVRC-12 are discussed and the field test system for digital data transmission using the ANVRC-12 is presented. Seven fixed transmission sites were used for transmission points to the laboratory where the analysis of the data was conducted. Map profiles of these sites are given and the audio SN and digital error rates measured over these transmission paths are presented. Error rates varied from 5 x 10 to the -6th power to 1 x 10 to the -3rd power depending upon the site and conditions. A table of average error rates shows that the error rate of a particular modem is almost independent of bit rate. Further analysis of the results show that single-bit errors, account for about 90 of the characters-in-error in the ANTYC-1 and Di- phase modems for transmission at 600 bps or less and in these cases error correction codes would be very effective. The cause of the errors is found to be impulse noise and photographs of the noise plus the signal is presented for discussion. The new digital data test system is discussed with the aid of a system block diagram. Both a printed record and a punched tape record of the error characteristics is provided.
- Radio Communications