Data Quality Metric (DQM) – How Accurate Does It Need To Be?

Abstract

A Data Quality Encapsulation (DQE) protocol for improving telemetry link quality has recently been standardized and added to IRIG 106. It periodically provides a Data Quality Metric (DQM) required for optimal Maximum Likelihood Bit Detection (MLBD) when more than one receive source is available. The resulting diversity can provide tremendous improvements in link quality. In order to be effective, the estimated DQM value should respond quickly and accurately to reflect the actual Bit Error Probability (BEP). This paper investigates the MLBD performance loss caused by DQM estimation error. The objective is to gain insight into the sensitivity of the overall bit recovery system and to use the results to help establish tolerance levels in DQM test procedures. This relationship provides the means to guarantee that the DQM accuracy is sufficient to meet or exceed a specified level of system performance which is the goal of DQM testing.