Method and circuits for reducing the peak power of the filtered signal transmitted in a digital link

Claim 1

A method for transmitting and receiving numerical signals, comprising the steps of: for transmission in a transmit channel; modulating data in a numeric sequence from a numeric or numerized source, thereby providing a modulated signal; filtering the modulated signal; and transmitting the filtered signal through the transmit channel which is a nonlinear channel where the nonlinearity may be due to a nonlinear characteristic of a final amplifier of a transmitter, or more generally to a nonlinear behaviour of the transmit channel, for reception of the filtered signal as a received signal in a receive channel; filtering the received signal, and demodulating the filtered received signal in order to reconstruct the transmitted numeric sequence, wherein for the transmission, prior to said step of filtering; identifying numeric sequences having a high peak power in terms of peak power of the filtered modulated signal, and replacing said numeric sequences having a high peak power in terms of peak power of the filtered modulated signal with suitable numeric sequences having a lower peak power in terms of peak power of the filtered modulated signal, thereby suppressing said numeric sequences having a high peak power in terms of peak power of the filtered modulated signal, and for the reception, prior to said step of demodulating; restoring the modulated signal from the received filtered signal by restoring the suppressed numeric sequences having a high peak power in terms of peak power of the filtered modulated signal, and sending the restored received filtered signal to a demodulator for performing said step of demodulating.

Claim 2

A method for transmitting and receiving numerical signals, comprising the steps of: for transmission in a transmit channel; modulating data in a numeric sequence from a numeric or numerized source, thereby providing a modulated signal; filtering the modulated signal; and transmitting the filtered signal through the transmit channel which is a nonlinear channel where the nonlinearity may be due to a nonlinear characteristic of a final amplifier of a transmitter, or more generally to a nonlinear behaviour of the transmit channel, for reception of the filtered signal as a received signal in a receive channel; filtering the received signal, and demodulating the filtered received signal in order to reconstruct the transmitted numeric sequence, wherein for the transmission, prior to said step of filtering; identifying numeric sequences having a high peak power in terms of peak power of the filtered modulated signal, and replacing said numeric sequences having a high peak power in terms of peak power of the filtered modulated signal with suitable numeric sequences having a lower peak power in terms of peak power of the filtered modulated signal, thereby suppressing said numeric sequences having a high peak power in terms of peak power of the filtered modulated signal, and for the reception, prior to said step of demodulating; restoring the modulated signal from the received filtered signal by restoring the suppressed numeric sequences having a high peak power in terms of peak power of the filtered modulated signal, and sending the restored received filtered signal to a demodulator for performing said step of demodulating.

Claim 6

A system for implementing a method of transmitting and receiving numerical signals, comprising: a transmission channel, including: a data source for providing data, an encoder/modulator for modulating said data in a numeric sequence thereby providing a modulated signal, a transmit filter for filtering the modulated signal, and a nonlinear amplifier for amplifying the filtered modulated signal; and a reception channel, including: a receive filter for filtering the received amplified filtered modulated signal, thereby providing a received filtered signal; and a decoder/demodulator for demodulating the received filtered signal, wherein the transmit channel further comprises an encoder including: means responsive to said modulated signal for identifying numeric sequences having a high peak power in terms of peak power of the filtered modulated signal; and means for replacing said numeric sequences having a high peak power in terms of peak power of the filtered modulated signal with suitable numeric sequences having a lower peak power in terms of peak power of the filtered modulated signal, thereby suppressing said numeric sequences having a high peak power in terms of peak power of the filtered modulated signal; and wherein the reception channel further comprises a decoder inserted downstream of the receive filter, the decoder including means for restoring the modulated signal from the received filtered signal by restoring the suppressed numeric sequences having a high peak power in terms of peak power of the filtered modulated signal.

Claim 7

A system for implementing a method of transmitting and receiving numerical signals, comprising: a transmission channel, including: a data source for providing data, an encoder/modulator for modulating said data in a numeric sequence thereby providing a modulated signal, a transmit filter for filtering the modulated signal, and a nonlinear amplifier for amplifying the filtered modulated signal; and a reception channel, including: a receive filter for filtering the received amplified filtered modulated signal, thereby providing a received filtered signal; and a decoder/demodulator for demodulating the received filtered signal, wherein the transmit channel further comprises an encoder including: means responsive to said modulated signal for identifying numeric sequences having a high peak power in terms of peak power of the filtered modulated signal; and means for replacing said numeric sequences having a high peak power in terms of peak power of the filtered modulated signal with suitable numeric sequences having a lower peak power in terms of peak power of the filtered modulated signal, thereby suppressing said numeric sequences having a high peak power in terms of peak power of the filtered modulated signal; and wherein the reception channel further comprises a decoder inserted downstream of the receive filter, the decoder including means for restoring the modulated signal from the received filtered signal by restoring the suppressed numeric sequences having a high peak power in terms of peak power of the filtered modulated signal.

Claim 11

A method for transmitting and receiving numerical signals, comprising the steps of: for transmission in a transmit channel: modulating data in a numeric sequence from a numeric or numerized source, thereby providing a modulated signal; filtering the modulated signal; and transmitting the filtered signal through the transmit channel which is a nonlinear channel where the nonlinearity may be due to a nonlinear characteristic of a final amplifier of a transmitter, or more generally to a nonlinear behaviour of the transmit channel, for reception of the filtered signal as a received signal in a receive channel: filtering the received signal, and demodulating the filtered received signal in order to reconstruct the transmitted numeric sequence, wherein for the transmission, prior to said step of filtering: identifying numeric sequences having a high peak power in terms of peak power of the filtered modulated signal, and replacing said numeric sequences having a high peak power in terms of peak power of the filtered modulated signal with suitable numeric sequences having a lower peak power in terms of peak power of the filtered modulated signal, thereby suppressing said numeric sequences having a high peak power in terms of peak power of the filtered modulated signal, wherein for the step of replacing said numeric sequences, previously-transmitted symbols are used for individuating a symbol to be transmitted, and wherein the individuation of the numeric sequences for replacement is carried out on the basis of the following equation: ##EQU4## for the reception, prior to said step of demodulating: restoring the modulated signal from the received filtered signal by restoring the suppressed numeric sequences having a high peak power in terms of peak power of the filtered modulated signal, and sending the restored received filtered signal to a demodulator for performing said step of demodulating.

Claim 12

A method for transmitting and receiving numerical signals, comprising the steps of: for transmission in a transmit channel: modulating data in a numeric sequence from a numeric or numerized source, thereby providing a modulated signal; filtering the modulated signal; and transmitting the filtered signal through the transmit channel which is a nonlinear channel where the nonlinearity may be due to a nonlinear characteristic of a final amplifier of a transmitter, or more generally to a nonlinear behaviour of the transmit channel, for reception of the filtered signal as a received signal in a receive channel: filtering the received signal, and demodulating the filtered received signal in order to reconstruct the transmitted numeric sequence, wherein for the transmission, prior to said step of filtering: identifying numeric sequences having a high peak power in terms of peak power of the filtered modulated signal, and replacing said numeric sequences having a high peak power in terms of peak power of the filtered modulated signal with suitable numeric sequences having a lower peak power in terms of peak power of the filtered modulated signal, thereby suppressing said numeric sequences having a high peak power in terms of peak power of the filtered modulated signal, wherein for the step of replacing said numeric sequences, previously-transmitted symbols are used for individuating a symbol to be transmitted, and wherein the individuation of the numeric sequences for replacement is carried out on the basis of the following equation: ##EQU4## for the reception, prior to said step of demodulating: restoring the modulated signal from the received filtered signal by restoring the suppressed numeric sequences having a high peak power in terms of peak power of the filtered modulated signal, and sending the restored received filtered signal to a demodulator for performing said step of demodulating.

Claim 14

A system for implementing a method of transmitting and receiving numerical signals, comprising: a transmission channel, including: a data source for providing data, an encoder/modulator for modulating said data in a numeric sequence thereby providing a modulated signal, a transmit filter for filtering the modulated signal, and a nonlinear amplifier for amplifying the filtered modulated signal; and a reception channel, including: a receive filter for filtering the received amplified filtered modulated signal, thereby providing a received filtered signal; and a decoder/demodulator for demodulating the received filtered signal, wherein the transmit channel further comprises an encoder including: means responsive to said modulated signal for identifying numeric sequences having a high peak power in terms of peak power of the filtered modulated signal; and means for replacing said numeric sequences having a high peak power in terms of peak power of the filtered modulated signal with suitable numeric sequences having a lower peak power in terms of peak power of the filtered modulated signal, thereby suppressing said numeric sequences having a high peak power in terms of peak power of the filtered modulated signal; and wherein said numeric sequences having a high peak power in terms of peak power of the filtered modulated signal are replaced with suitable numeric sequences having a lower peak power in terms of peak power of the filtered modulated signal on the basis of the following equation: ##EQU5## wherein the reception channel further comprises a decoder inserted downstream of the receive filter, the decoder including means for restoring the modulated signal from the received filtered signal by restoring the suppressed numeric sequences having a high peak power in terms of peak power of the filtered modulated signal.

Claim 15

A system for implementing a method of transmitting and receiving numerical signals, comprising: a transmission channel, including: a data source for providing data, an encoder/modulator for modulating said data in a numeric sequence thereby providing a modulated signal, a transmit filter for filtering the modulated signal, and a nonlinear amplifier for amplifying the filtered modulated signal; and a reception channel, including: a receive filter for filtering the received amplified filtered modulated signal, thereby providing a received filtered signal; and a decoder/demodulator for demodulating the received filtered signal, wherein the transmit channel further comprises an encoder including: means responsive to said modulated signal for identifying numeric sequences having a high peak power in terms of peak power of the filtered modulated signal; and means for replacing said numeric sequences having a high peak power in terms of peak power of the filtered modulated signal with suitable numeric sequences having a lower peak power in terms of peak power of the filtered modulated signal, thereby suppressing said numeric sequences having a high peak power in terms of peak power of the filtered modulated signal; and wherein said numeric sequences having a high peak power in terms of peak power of the filtered modulated signal are replaced with suitable numeric sequences having a lower peak power in terms of peak power of the filtered modulated signal on the basis of the following equation: ##EQU5## wherein the reception channel further comprises a decoder inserted downstream of the receive filter, the decoder including means for restoring the modulated signal from the received filtered signal by restoring the suppressed numeric sequences having a high peak power in terms of peak power of the filtered modulated signal.