Agilent Technologies Switch/Measure Manual do Utilizador descarregar pdf (Página 8)

Graphical view of limits and specifications

The ETSI and ANSI specifications define test limits for both base transceiver

stations and mobiles. Phase and frequency error measurements should be

performed over multiple bursts, and on multiple channels. Actual transmitter

performance will vary with frequency.

It is worth noting that for frequency error the pass/fail limit is expressed in terms

of ppm (parts per million) and applies across GSM900, DCS1800 and PCS1800.

The phase error limits are also common across the three systems.

+20°

–20°

Time (bits)

Gradient of line = Mean frequency error

limit = 0.05 ppm = 45 Hz (approx)

Bit 147

Bit 0

RMS phase error

limit is 5°

Peak phase

error limit

Absolute phase

error (deg)

Example: E-GSM900, BTS

Channels:

B, M, T. Single carrier

At least one slot on

Hopping:

Off or On

Detection:

Measured over useful

part of burst (gated)

Figure 4. Phase error and mean frequency error, BTS, limits

1 2 3 4 5 6 7 8 9 10 11 12 13 ... 35 36

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Agilent Technologies Switch/Measure Manual do Utilizador Página 8