Perfect signal processing (filtering) is essential for the best decoding results which are achieved by using the correct filters in the receiver. Doing so prevents blocking effects from strong nearby signals. However correctly processed signals may be unavailable, e.g., when a receiver does not offer optimum filters or when using recorded signals. To overcome these obstacles additional passband filters are included in the WAVECOM decoders to assist the operator in separating signals within the analyzed frequency spectrum.
Depending on the demodulator (Modulation) used by a mode the user may set the passband filter parameters: Passband Center, Passband Bandwidth and Center. (See the table below).
|
Item |
PB Conf. |
Remarks |
|
DSP |
+ |
Freely configurable |
|
AM |
+ |
Freely configurable |
|
CW |
+ |
Freely configurable |
|
GFSK |
+ |
PB center frequency controlled from offset frequency setting |
|
FFSK |
+ |
PB center frequency controlled from offset frequency setting |
|
MARK-SPACE |
- |
PB automatically adjusted depending on center, shift and speed |
|
MFSK |
- |
Individual tones are filtered and PB automatically adjusted depending on tone spacing, center and speed |
|
DTMF |
- |
Individual tones are filtered and PB automatically adjusted depending on tone spacing, center and speed |
|
BR6028 |
- |
Preconfigured filters that cannot be changed. The location of the pilot tone can be manually set |
|
BPSK |
+ |
Freely configurable |
|
QPSK |
+ |
Freely configurable |
|
OQPSK |
+ |
Freely configurable |
|
DPSK |
- |
PB bandwidth automatically adjusted depending on center, shift and speed. The center frequency can be manually set |
|
DXPSK |
- |
PB bandwidth automatically adjusted depending on center, shift and speed. The center frequency can be manually set |
|
DBPSK |
- |
PB bandwidth automatically adjusted depending on center, shift and speed. The center frequency can be manually set |
|
DQPSK |
- |
PB bandwidth automatically adjusted depending on center, shift and speed. The center frequency can be manually set |
|
D8PSK |
- |
PB bandwidth automatically adjusted depending on center, shift and speed. The center frequency can be manually set |
|
D16PSK |
- |
PB bandwidth automatically adjusted depending on center, shift and speed. The center frequency can be manually set |
|
IQ |
+ |
Freely configurable |
|
ANALYSE |
+ |
Freely configurable |
|
FFT |
- |
No filtering implemented |
|
TIME |
- |
No filtering implemented |
|
OFDM |
- |
No filtering implemented |
|
SUBTONE |
- |
No filtering implemented |
|
DISCRIMINATOR |
- |
No filtering implemented |
|
EXT-DEM |
- |
No filtering implemented |
|
BYPASS |
- |
No filtering implemented |