Convolutional Encoder COM-1010 -> DSSS modulator COM-1019 -> 
DSSS demodulator COM-1018 -> Convolutional Decoder, K=7 COM1009 -> BER measurement COM-1005.


Test configuration example: 
- Direct sequence spread-spectrum
- 19.9 Mchip/s
- Spreading code: Barker, length 13. QPSK
- Data rate (after convolutional encoding): 3.06 Mbps.
- No noise. 
- error correction K=7 rate = 1/2
- PRBS-11 sequence is being transmitted.

The convolutional encoder is placed in signal generator test mode, 
whereby a periodic 2047-bit sequence (PRBS-11) is being transmitted. 
The resulting data stream is modulated with direct sequence spread-spectrum, and then DSSS demodulated. 
The end to end BER is measured using the COM-1005 module. 

Proper operation can be verified as follows:

(a) COM-1018 monitoring register 23 is 0x03, indicating both carrier and code lock 
conditions.

(b) using an oscilloscope probe:

COM-1005 TP1 is high, indicating synchronization with the 2047-bit periodic test pattern. 

COM-1005 TP3 is low, showing no bit error pulse.

COM-1005 TP4 shows the detected start of PRBS-11 sequence every other 2047 bit (1.34ms)

(c) from the ComBlock control center check the BER (COM-1005 status).
It will show no bit errors (REG 1 through 4) and the synchronization bit (REG5 bit0) is high.
The BER is 0.
The Demodulator phase ambiguity is removed by the Viterbi decoder.