Portable GPS-receiver for a personal safety system

A portable GPS-receiver for a system of personal safety comprising:

• sequentially connected input and output units;
• a data input-output unit;
• and
• a transceiver unit for a reception and a transmission of data through a communication channel,
• wherein
• the communication channel links the portable GPS receiver with a base station,
• an output of a reference signal of the transceiver unit is connected to a reference input of the input unit,
• a clock input of the output unit is connected to a clock output of the input unit,
• the input unit comprises:
• a radio frequency signal converter, whose signal input is a signal input of the input unit;
• an analog-to-digital conversion of signals unit, whose output is a signal output of the input unit, wherein the radio frequency converter and the analog-to-digital conversion of signals unit are sequentially connected;
• and
• a former of signals of clock and heterodyne frequencies, wherein a reference input of the former is a reference input of the input unit, a heterodyne output of the former is connected to a heterodyne input of the radio frequency signal converter, and a clock output of the former, being a clock output of the input unit, is connected to a clock input of the unit of analog-to-digital conversion of signals,
• the output unit further comprising:
• a multichannel digital correlator with N=8 to 12 channels of parallel processing;
• a microprocessor connected with the multichanel digital correlator, the microprocessor comprising:
• a constant storage for storage of programs of signal processing;
• and an operative storage for storage of data used by the portable GPS-receiver when operating in a standard mode without blockage of GPS signals;
• an additional constant storage;
• and
• an additional operative storage,
• wherein the microprocessor is connected by data buses to:
• the former of the signals of clock and heterodyne frequencies, to the data input-output unit,
• the transceiver unit,
• the additional permanent storage for storage of the programs of signal processing, and
• the additional operative storage for storage of data and calculated values of the multichannel digital correlator used by the portable GPS receiver when operating in conditions of blockage of GPS signals, and
• wherein each of the N channels of the multichannel digital correlator comprises K inphase and K quadrature correlators, where K=20 to 40, connected with corresponding ones of the permanent and operative storage units, thereby ensuring simultaneous correlation of GPS signals with K copies of a C/A code of GPS, shifted by one half of a digit of the C/A code of GPS, and coherent accumulation of results of a correlation on an interval equal to a duration of an epoch of C/A code.