Lossless Compression Handbook

250

PART III/APPLICATIONS

Major Frame

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SubFrame

FIGURE 11.4

Major flame structure for telemetry data [3].

sensor 1

sensor 2

sensor 3

sensor 4

sensor 1

sensor 2

sensor 3

sensor 4

minor frame 1

minor frame "m"

FIGURE 11.5

Minor frame structure for telemetry frames [3].

11.2 ISSUES INVOLVED IN COMPRESSION OF TELEMETRY

11.2.1 Why Use Compression on Telemetry

Bandwidth is a precious commodity. Bandwidth is the amount of frequency space that a signal

takes to transmit its information. There are several different definitions of bandwidth. Two common

definitions are the 3-dB bandwidth and the null-to-null bandwidth. For a given power spectrum

of a signal, the 3-dB bandwidth is where the signal power is down 3 dB from the maximum.