System and method for diversity reception of signals

Claim 1

A system for diversity reception of signals with first and second receivers, respectively adapted to recover and output first and second recovered baseband signals, said system comprising: (a) first and second wave detector means, respectively, in the first and second receivers for generating output voltages corresponding to the strengths of a modulated electromagnetic signal wave reaching the respective receivers; (b) comparator means coupled to the first and second receivers for detecting and for giving an output detection signal when the difference in output voltages between the first and second wave detectors exceeds a predetermined value; (c) adder circuit means responsive to the first and second recovered baseband signals for correlating and combining said baseband signals; (d) first and second switching circuits selectively capable of cutting off the first or second recovered signal from the adder circuit means, and a third switching circuit coupled to adjust the gain of the adder circuit by selectively reducing it by one half; (e) means responsive to the comparator means for controlling the first and second switching circuits to cut off only the recovered baseband signal being applied from the receiver having a lower output voltge to the adder circuit means; and (f) means responsive to an absence of the comparator output detection signal for controlling the first and second switching circuits to cause both the first and second recovered baseband signals to be input to the adder circuit, and at the same time for controlling the third switching circuit to reduce the gain of the adder circuit by one half; thereby producing a diversity output signal with substantially uniform gain as the output of the adder circuit.

Claim 2

A system for diversity reception of signals with first and second receivers, respectively adapted to recover and output first and second recovered baseband signals, said system comprising: (a) first and second wave detector means, respectively, in the first and second receivers for generating output voltages corresponding to the strengths of a modulated electromagnetic signal wave reaching the respective receivers; (b) comparator means coupled to the first and second receivers for detecting and for giving an output detection signal when the difference in output voltages between the first and second wave detectors exceeds a predetermined value; (c) adder circuit means responsive to the first and second recovered baseband signals for correlating and combining said baseband signals; (d) first and second switching circuits selectively capable of cutting off the first or second recovered signal from the adder circuit means, and a third switching circuit coupled to adjust the gain of the adder circuit by selectively reducing it by one half; (e) means responsive to the comparator means for controlling the first and second switching circuits to cut off only the recovered baseband signal being applied from the receiver having a lower output voltge to the adder circuit means; and (f) means responsive to an absence of the comparator output detection signal for controlling the first and second switching circuits to cause both the first and second recovered baseband signals to be input to the adder circuit, and at the same time for controlling the third switching circuit to reduce the gain of the adder circuit by one half; thereby producing a diversity output signal with substantially uniform gain as the output of the adder circuit.

Claim 3

A system for diversity reception of signals, said system having a plurality of receivers and comprising means for comparing the levels of signals reaching said plurality of receivers; means responsive to the comparing means for adding and combining the signals recovered by said plurality of receivers; switching means for cutting off the weaker of the output signals from the receivers when the difference between compared level reaches a threshold level; and means for adjusting the gain of said adding and combining means to maintain a uniform signal level regardless of the switching of said signals by said switching means.

Claim 4

A system for diversity reception of signals, said system having a plurality of receivers and comprising means for comparing the levels of signals reaching said plurality of receivers; means responsive to the comparing means for adding and combining the signals recovered by said plurality of receivers; switching means for cutting off the weaker of the output signals from the receivers when the difference between compared level reaches a threshold level; and means for adjusting the gain of said adding and combining means to maintain a uniform signal level regardless of the switching of said signals by said switching means.

Claim 7

A system for diversity reception of signals at a plurality of mobile receivers, said system comprising at least two FM receivers, each of said receivers including an envelope detector means, a pair of difference amplifier means coupled to individually associated ones of said receivers for comparing levels of the output of said detector means, adding means responsive to the outputs of said difference amplifiers for combining said outputs of said detector means and of said receivers, switching means for opening a path from one of said receivers having a low level output in response to said comparing means finding a difference in said detector means output levels which exceeds a given amount, and means for adjusting a gain of said adding means to maintain a given output level regardless of whether said adding means receives an output from one or more of said receivers.

Claim 8

A system for diversity reception of signals at a plurality of mobile receivers, said system comprising at least two FM receivers, each of said receivers including an envelope detector means, a pair of difference amplifier means coupled to individually associated ones of said receivers for comparing levels of the output of said detector means, adding means responsive to the outputs of said difference amplifiers for combining said outputs of said detector means and of said receivers, switching means for opening a path from one of said receivers having a low level output in response to said comparing means finding a difference in said detector means output levels which exceeds a given amount, and means for adjusting a gain of said adding means to maintain a given output level regardless of whether said adding means receives an output from one or more of said receivers.

Claim 12

A method for diversity reception of signals for use with a first receiver and a second receiver, respectively adapted to recover and output a first recovered baseband signal and a second recovered baseband signal, said method for diversity reception comprising the steps of: (a) providing, respectively for the first and second receivers, first and second wave detectors for generating output voltages corresponding to the strength of the modulated electromagnetic signal wave reaching the respective receiver; (b) connecting up to the first and second receivers: comparator means for detecting when the difference in output voltage between the first and second wave detectors exceeds a predetermined value and for outputing a detection signal to that effect, and an adder circuit adapted to receive the first and second recovered baseband signals as input and combine them in correlation; (c) providing first and second switching circuits selectively capable of cutting off the first or second recovered signal being input to the operational adder circuit, and providing a third switching circuit capable of adjusting the gain of the adder circuit by reducing it by half; (d) when the comparator means outputs the detection signal, controlling the first and second switching circuits so that they cause just the recovered baseband signal being input to the adder circuit from the receiver having the wave detector with the low output voltage to be cut off; and (e) when the comparator is not outputting the detection signal: controlling the first and second switching circuits so that they cause both the first and second recovered baseband signals to be input to the adder circuit, and at the same time controlling the third switching circuit so as to reduce the gain of the adder circuit by half; thereby producing the desired diversity output signal as the output of the adder circuit.

Claim 13

A method for diversity reception of signals for use with a first receiver and a second receiver, respectively adapted to recover and output a first recovered baseband signal and a second recovered baseband signal, said method for diversity reception comprising the steps of: (a) providing, respectively for the first and second receivers, first and second wave detectors for generating output voltages corresponding to the strength of the modulated electromagnetic signal wave reaching the respective receiver; (b) connecting up to the first and second receivers: comparator means for detecting when the difference in output voltage between the first and second wave detectors exceeds a predetermined value and for outputing a detection signal to that effect, and an adder circuit adapted to receive the first and second recovered baseband signals as input and combine them in correlation; (c) providing first and second switching circuits selectively capable of cutting off the first or second recovered signal being input to the operational adder circuit, and providing a third switching circuit capable of adjusting the gain of the adder circuit by reducing it by half; (d) when the comparator means outputs the detection signal, controlling the first and second switching circuits so that they cause just the recovered baseband signal being input to the adder circuit from the receiver having the wave detector with the low output voltage to be cut off; and (e) when the comparator is not outputting the detection signal: controlling the first and second switching circuits so that they cause both the first and second recovered baseband signals to be input to the adder circuit, and at the same time controlling the third switching circuit so as to reduce the gain of the adder circuit by half; thereby producing the desired diversity output signal as the output of the adder circuit.