Abstract: A lock detector circuit (60) for demodulators of UQPSK signals I and Q has signal processing circuits for forming the signals:A=6I.sup.2 Q.sup.2 -I.sup.4 -Q.sup.4 ;B=4(I.sup.2 -Q.sup.2).A switch (19) is provided for coupling either signal A or signal B to the output (20) of the detector circuit, depending on the value of the signal ratio Q/I. In an alternative embodiment, a summing circuit adds signal A and signal B, and directs the sum to the detector output (20). The resulting output signal is constant under lock conditions, and oscillates when the demodulator is unlocked. This output signal is directed through a comparator (49) to the sweep circuit (43) controlling demodulator VCO (42), and causes the demodulator to remain in the locked condition. The lock detector circuit is effective for any value of Q/I, and utilizes only three analog multiplier circuits.

Abstract: The Incident Location Reporting Security System pertains to a device that is capable of determining instantaneously, via the use of pulse-width coded modulation, the location of incidences such as burglary, robbery and fire. Detailed multi-point monitoring can be carried out in such varied sites in a multistory buildings, residential neighborhoods, museums or individuals. The concept allows for generation and reading of billions of different codes through the simplistic design of a coded receiver wherein codes are read instead of matched. In achieving this capability, a base number is created by multiplying the plurality of positions of a switch times the number of switches and thereafter pulsing a transmitter a number of times to generate a code in which the base number is raised to the power of the number of times it is pulsed. Each transmitter is assigned a specific coded number and a single receiver rapidly processes and identifies any coded number received.