November 1998 | NTIA Technical Report TR-99-358

Delivered Audio Quality Measurements on Project 25 Land Mobile Radios

John M. Vanderau

Abstract: Minimum acceptable speech intelligibility of land mobile radios is influenced by a number of factors. These factors include the method of modulation, transmission bandwidth, channel spacing, received signal strength, and the ability of a radio receiver to capture a desired signal in the presence of interfering signals and noise. The Institute for Telecommunication Sciences has compared the speech quality performance of the new generation of Project 25 land mobile radios to analog FM systems.

Keywords: interference; land mobile radio; bit error rate (BER); co-channel interference; C/I; adjacent channel interference; delivered audio quality; Project 25 (P25); reference sensitivity level; SINAD

To request a reprint of this report, contact:

Lilli Segre, Publications Officer
Institute for Telecommunication Sciences
(303) 497-3572
LSegre@ntia.gov

Disclaimer: Certain commercial equipment, components, and software may be identified in this report to specify adequately the technical aspects of the reported results. In no case does such identification imply recommendation or endorsement by the National Telecommunications and Information Administration, nor does it imply that the equipment or software identified is necessarily the best available for the particular application or uses.

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