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Spreadspectrum AKF has 4 bit range

In the telecommunication code multiplex technology, the modulated signal is spread with a codeword. This technique is called spread spectrum. (SPRSP). In a SPRSP receiver the code word must be found and looked to be received. Fig. 1 shows a standard delay look loop to be locked to the code word which has a certain length, for instance 256 bit. We see here a code generator to generate a certain code-word.-The code generator is shifted in its phase from a voltage controlled oscillator to be locked in with the incoming, code word. If they coincide, the loop is looked. The shifting of the code word versus the incoming code word has a control AKF-function of Fig.2 The linear look-in control range of the feedback is plus minus 1 bite. Outside this control function the loop may flip out and the signal path is interrupted. In Fig. 3 is a new AKF-Loop shown where the lock-in range is twice. The total lock in process is now easier and faster. This broader AKF is reached by summarizing the output voltages of the detector instead of subtracting them and switch the code generator periodically plus minus one bit.


                                                                     Fig.1 Standard delay look loop 

.                                                                     Fig.2 A new delay look loop