Method for the reception and detection of digital signals

Claim 1

A method for the reception and the detection of digital signals, comprising the steps of: receiving at least two signals (s 1 , s 2 , . . . , s M ) having at least approximately the same information content, by means of at least one antenna or equivalent; subjecting at least all received signals (s 1 , s 2 , . . . , s M ) but one to a phase shift or to an amplitude shift and a phase shift; combining the shifted signals (s' 1 , s' 2 , . . . , s' M ) at a summing point to obtain a sum signal (s); feeding the sum signal (s) to a detector for detection; generating in a reference carrier generator a reference carrier; carrying out a coherent demodulation and detection in the detector by means of said carrier; generating a projection voltage (z k ) defined by the following equation z.sub.k =y.sub.Qk s.sub.Ik -Y.sub.Ik s.sub.Qk ; wherein y Ik is a signal sample in an in-phase branch before threshold decision in the detector, y Qk is a signal sample in a quadrature branch before decision in the detector, s Ik is the detected signal in said in-phase branch, and s Qk is the detected signal in said quadrature branch; generating a product signal (b) by multiplying said sum signal (s) with said projection voltage (z k ); generating control voltages (c 1 , . . . , c M ) by correlating said product signal (b) with the received signals of each branch under consideration; and controlling at least the phase shifts by means of said control voltages (c 1 , . . . , c M ) in increments proportional to said control voltages until said control voltages reach a zero value.

Claim 2

A method for the reception and the detection of digital signals, comprising the steps of: receiving at least two signals (s 1 , s 2 , . . . , s M ) having at least approximately the same information content, by means of at least one antenna or equivalent; subjecting at least all received signals (s 1 , s 2 , . . . , s M ) but one to a phase shift or to an amplitude shift and a phase shift; combining the shifted signals (s' 1 , s' 2 , . . . , s' M ) at a summing point to obtain a sum signal (s); feeding the sum signal (s) to a detector for detection; generating in a reference carrier generator a reference carrier; carrying out a coherent demodulation and detection in the detector by means of said carrier; generating a projection voltage (z k ) defined by the following equation z.sub.k =y.sub.Qk s.sub.Ik -Y.sub.Ik s.sub.Qk ; wherein y Ik is a signal sample in an in-phase branch before threshold decision in the detector, y Qk is a signal sample in a quadrature branch before decision in the detector, s Ik is the detected signal in said in-phase branch, and s Qk is the detected signal in said quadrature branch; generating a product signal (b) by multiplying said sum signal (s) with said projection voltage (z k ); generating control voltages (c 1 , . . . , c M ) by correlating said product signal (b) with the received signals of each branch under consideration; and controlling at least the phase shifts by means of said control voltages (c 1 , . . . , c M ) in increments proportional to said control voltages until said control voltages reach a zero value.

Claim 12

A method for the reception and the detection of digital signals, comprising the steps of: receiving two signals having at least approximately the same information content, by means of at least one antenna or equivalent; subjecting a first of said two signals to a phase shift; summing said phase-shifted first signal and a second of said two signals at a summing point to produce a sum signal; feeding the sum signal to a detector for detection; generating a reference carrier; carrying out a coherent demodulation and detection in the detector by means of said carrier (ca); generating a projection voltage (z k ) defined by the following equation z.sub.k =y.sub.Qk s.sub.Ik -y.sub.Ik s.sub.Qk, wherein y Ik is a signal sample in an in-phase branch before threshold decision in the detector, y Qk is the signal sample in a quadrature branch before detection, s Ik is the detected signal in the in-phase branch, and s Qk is the detected signal in the quadrature branch; generating a first product signal by multiplying said second signal with the shifted signal; generating a second product signal by multiplying the first product signal with the projection voltage (z k ); averaging the second product signal by forming a floating average; and controlling the phase shift by means of the averaged signal in increments proportional to said averaged signal until said averaged signal reaches zero.

Claim 13

A method for the reception and the detection of digital signals, comprising the steps of: receiving two signals having at least approximately the same information content, by means of at least one antenna or equivalent; subjecting a first of said two signals to a phase shift; summing said phase-shifted first signal and a second of said two signals at a summing point to produce a sum signal; feeding the sum signal to a detector for detection; generating a reference carrier; carrying out a coherent demodulation and detection in the detector by means of said carrier (ca); generating a projection voltage (z k ) defined by the following equation z.sub.k =y.sub.Qk s.sub.Ik -y.sub.Ik s.sub.Qk, wherein y Ik is a signal sample in an in-phase branch before threshold decision in the detector, y Qk is the signal sample in a quadrature branch before detection, s Ik is the detected signal in the in-phase branch, and s Qk is the detected signal in the quadrature branch; generating a first product signal by multiplying said second signal with the shifted signal; generating a second product signal by multiplying the first product signal with the projection voltage (z k ); averaging the second product signal by forming a floating average; and controlling the phase shift by means of the averaged signal in increments proportional to said averaged signal until said averaged signal reaches zero.