Agilent Technologies ESG Podręcznik Użytkownika Strona 274

  • Pobierz
  • Dodaj do moich podręczników
  • Drukuj
Przeglądanie stron 273
258 Chapter 10
GPS Modulation
GPS Concepts
Data Modes and Subframe Structures
The GPS personality lets you transmit data three different ways using the C/A or C/A+P
ranging code selection:
A raw (Raw) data mode which enables the continuous transmission of 300 bits of data per
subframe without incorporating parity bits. This is well suited for BER and low-level
demodulation testing.
An encoded (Enc) data mode which enables the continuous transmission of 10 words
(30-bits each) per subframe, with each word containing 24 bits of raw data along with 6
trailing parity bits computed from the selected data by the ESG.
The telemetry (TLM) mode which enables the continuous transmission of a formatted TLM
and handover word (HOW) along with default navigation data as outlined in the GLOBAL
POSITIONING SYSTEM STANDARD POSITIONING SERVICE SIGNAL
SPECIFICATION, 2nd Edition, June 2, 1995. This is a good mode for testing receiver
functionality. For example, the C/No can be determined by testing the sensitivity of the
receiver accepting the data.
Figure 10-2 shows the subframe structures for each data mode.
Figure 10-2 Subframe Structures
Przeglądanie stron 273
1 2 ... 269 270 271 272 273 274 275 276 277 278 279 ... 501 502

Komentarze do niniejszej Instrukcji

Brak uwag