This page contains some hard-to-find technical resources for DSP engineers – miscellaneous items that we have found extremely useful over the course of more than 25 years DSP software/hardware development and integration.
- Federal Standard 1023: Interoperability Requirements for Encrypted, Digitized Voice Utilized with 25 KHz Channel FM Radios Operating Above 30 MHz
This standard establishes interoperability requirements regarding the analog to digital conversion, encryption (with related synchronization), and modulation of encrypted voice associated with Frequency Modulation (FM) radio systems employing 25 kHz channels and operating above 30 MHz. In this standard, voice is digitized using 12 kbit/s Continuously Variable Slope Delta modulation (CVSD) and then encrypted using a National Security Agency (NSA) Commercial COMSEC Endorsement Program (CCEP) Type I encryption algorithm.
- Department of Defencse Interface Standard MIL-STD-188-110B: Interoperability and Performance Standards for Data Modems
This document establishes mandatory technical standards and design objectives (DO) that are necessary to ensure interoperability and to promote performance among data modulators-demodulators (modems) used in the voice frequency (VF) band of long-haul and tactical communications systems. This document also provides guidance to the designers of new data modems that incorporate characteristics not yet standardized by specifying the technical characteristics of data modems currently in the inventory. The purpose of this guidance is to ensure attainment of minimum acceptable performance and maximum interoperability between existing and future data modems with specified transmission channel conditions.