Receiving spread spectrum signals

A method for receiving spread spectrum signals comprising the following steps:

• preprocessing and digitizing a received spread spectrum signal,
• tracking the digitized received spread spectrum signal by means of a carrier loop and a code loop, wherein the tracking comprises generating a reference receiver signal for correlation with the received spread spectrum signal in the code loop and shaping a correlation function between the received spread spectrum signal and the reference receiver signal by modifying the reference receiver signal in the code loop,
• wherein one of
• the received spread spectrum signal is multiplied with a first analog spectral offsetting signal provided for down-converting the received spread spectrum signal to an intermediate frequency IF0 and a sub-carrier frequency fm selected from a set of M sub-carrier frequencies such that the received spread spectrum signal is down-converted and spectrally offset in the analog domain during a time interval covering Lm chips, wherein Lm chips comprises at least one chip of a spreading code of the received spread spectrum signal,
• or
• the received spread spectrum signal is multiplied with a second analog spectral offsetting signal provided for down-converting the received spread spectrum signal to an intermediate frequency IF0 in the analog domain, for digitizing the down-converted received spread-spectrum signal, and for multiplying the digitized and down-converted received spread spectrum signal with a digital spectral offsetting signal provided for spectrally offsetting the digitized and down-converted received spread spectrum signal in the digital domain to a sub-carrier frequency fm selected from a set of M sub-carrier frequencies such that the digitized and down-converted received spread spectrum signal is spectrally offset in the digital domain during a time interval covering Lm chips, wherein Lm chips comprises at least one chip of a spreading code of the received spread spectrum signal;
• wherein the first analog spectral offsetting signal is defined by ej(2π(fRF+IF0+fm)(t−τest,prec)+φm), and the second analog spectral offsetting signal is defined by ej(2π(fRF+IF0)(t−τest,prec)) and the digital spectral offsetting signal is defined by ej(2π(fm)(t−τest,prec)+φm)
• with t being a time variable,
• fm being a sub-carrier frequency selected from the set of M sub-carrier frequencies and applied during a time interval covering Lm chips,
• τest,prec being a time offset, which is used for synchronization and is a function of the actual propagation delay τ of the transmitted signal up to the receiver and is estimated in a τest,prec generator from at least one of the past outputs of the code loop and/or carrier loop of the receiver, and/or is estimated by an external estimator of the propagation delay to the receiver and processed by the τest,prec generator, and
• φm being a phase which ensures that the argument of the exponential term is continuous at a transition between two consecutive sub-carrier frequencies fm and fm+1.

A method for receiving spread spectrum signals comprising the following steps:

• preprocessing and digitizing a received spread spectrum signal,
• tracking the digitized received spread spectrum signal by means of a carrier loop and a code loop, wherein the tracking comprises generating a reference receiver signal for correlation with the received spread spectrum signal in the code loop and shaping a correlation function between the received spread spectrum signal and the reference receiver signal by modifying the reference receiver signal in the code loop,
• wherein one of
• the received spread spectrum signal is multiplied with a first analog spectral offsetting signal provided for down-converting the received spread spectrum signal to an intermediate frequency IF0 and a sub-carrier frequency fm selected from a set of M sub-carrier frequencies such that the received spread spectrum signal is down-converted and spectrally offset in the analog domain during a time interval covering Lm chips, wherein Lm chips comprises at least one chip of a spreading code of the received spread spectrum signal,
• or
• the received spread spectrum signal is multiplied with a second analog spectral offsetting signal provided for down-converting the received spread spectrum signal to an intermediate frequency IF0 in the analog domain, for digitizing the down-converted received spread-spectrum signal, and for multiplying the digitized and down-converted received spread spectrum signal with a digital spectral offsetting signal provided for spectrally offsetting the digitized and down-converted received spread spectrum signal in the digital domain to a sub-carrier frequency fm selected from a set of M sub-carrier frequencies such that the digitized and down-converted received spread spectrum signal is spectrally offset in the digital domain during a time interval covering Lm chips, wherein Lm chips comprises at least one chip of a spreading code of the received spread spectrum signal, wherein the steps of down-converting and digitizing of the received spread spectrum signal comprises either the synthesizing of frequency references for down-converting the received spread spectrum signal to the intermediate frequency IF0 and the sub-carrier frequency fm and for digitizing the down-converted received spread spectrum signal, or the synthesizing of frequency references for down-converting the received spread spectrum signal to the intermediate frequency IF0 and for digitizing the down-converted received spread spectrum signal and for spectrally offsetting the down-converted digital spread spectrum signal to the sub-carrier frequency fm.

A method for receiving spread spectrum signals comprising the following steps:

• preprocessing and digitizing a received spread spectrum signal,
• tracking the digitized received spread spectrum signal by means of a carrier loop and a code loop, wherein the tracking comprises generating a reference receiver signal for correlation with the received spread spectrum signal in the code loop and shaping a correlation function between the received spread spectrum signal and the reference receiver signal by modifying the reference receiver signal in the code loop,
• wherein one of
• the received spread spectrum signal is multiplied with a first analog spectral offsetting signal provided for down-converting the received spread spectrum signal to an intermediate frequency IF0 and a sub-carrier frequency fm selected from a set of M sub-carrier frequencies such that the received spread spectrum signal is down-converted and spectrally offset in the analog domain during a time interval covering Lm chips, wherein Lm chips comprises at least one chip of a spreading code of the received spread spectrum signal,
• or
• the received spread spectrum signal is multiplied with a second analog spectral offsetting signal provided for down-converting the received spread spectrum signal to an intermediate frequency IF0 in the analog domain, for digitizing the down-converted received spread-spectrum signal, and for multiplying the digitized and down-converted received spread spectrum signal with a digital spectral offsetting signal provided for spectrally offsetting the digitized and down-converted received spread spectrum signal in the digital domain to a sub-carrier frequency fm selected from a set of M sub-carrier frequencies such that the digitized and down-converted received spread spectrum signal is spectrally offset in the digital domain during a time interval covering Lm chips, wherein Lm chips comprises at least one chip of a spreading code of the received spread spectrum signal, wherein as spread spectrum signal a signal with any pulse shape type and particularly a Binary-Phase-Shift-Keying—BPSK(N)—modulated spread spectrum signal such that the combination of the reference receiver signal multiplied with the offsetting signal can be replaced with a Binary Offset Carrier (BOC) (K,N) reference receiver signal if the set of M sub-carrier frequencies contains only 2 frequencies +fK and −fK and the duration of the time intervals when +fk is applied is identical to the duration of the time intervals when −fk is applied, is received.