Coherent spread spectrum pseudonoise tracking loop

Claim 2

A detector for use in a communication receiver where a received data signal is detected using a locally generated reference signal to decode the received data signal comprising: first channel means; second channel means; means for applying the received spread data signal to said first and second channel means; local generator means for generating the reference signal wherein the reference signal includes polarity transitions; said first channel means including demodulation means for generating a detected recovered data signal from said received spread data signal in response to the reference signal; means for detecting said polarity transitions in the reference signal and for generating a differential PN signal; said second channel means including means for correlating the received spread data signal and said differential PN signal to thereby generate a recovered error signal; and means for correlating said recovered data siganl and said recovered error signal to thereby generate a control signal for application to said local generator means for locking the reference signal to a component of the received spread data signal.

Claim 3

The detector of claim 1 and further including: means for filtering said control signal prior to application of said control signal to said local generator means.

Claim 4

The detector of claim 1 wherein said local generator means includes: pseudonoise signal generator means for generating a pseudonoise sequence signal which corresponds to a pseudonoise signal component of the received spread data signal.

Claim 5

The detector of claim 3 wherein the phase of said pseudonoise signal generated by said pseudonoise signal generator means is controlled by said control signal.

Claim 6

The detector of claim 3 wherein said local generator means further includes: voltage controlled oscillator means responsive to said control signal for clocking said pseudonoise signal generator means.

Claim 7

The detector of claim 1 wherein said means for detecting the polarity transitions in the reference signal comprises means for differentiating the reference signal.

Claim 8

The detector of claim 6 wherein said means for differentiating includes double balance mixer means.

Claim 9

The detector of claim 1 wherein said first channel means further includes: data filter means for filtering said detected recovered data signal.

Claim 10

The detector of claim 1 wherein said second channel means further includes: data filter means for filtering said recovered error signal.

Claim 11

The detector of claim 1 wherein the received spread data signal comprises baseband frequency data.

Claim 12

The detector of claim 1 wherein the received spread data signal comprises intermediate frequency data.

Claim 13

In a receiver for a spread specturm encoded signal wherein the received spread spectrum signal includes a carrier signal that has been phase modulated by a data signal and by a pseudonoise signal, a detector comprising: first channel means; second channel means; means for applying the received spread spectrum signal to said first and second channel means; local generator means for generating a pseudonoise sequence signal having phase transitions which corresponds to the pseudonoise signal component of the received spread spectrum signal; said first channel means including demodulation means for correlating the pseudonoise signal component of the received spread spectrum signal with said pseudonoise sequence signal generated by said local generator means to thereby generate a detected recovered signal; means for detecting the polarity of said phase transitions of said pseudonoise reference signal and for generating a differential PN signal; means for correlating the received spread spectrum encoded signal and said error signal to thereby generate a recovered error signal; and means for correlating said detected recovered signal and said recovered error signal to therby generate a control signal for application to said local generator means, wherein said control signal controls the phase of said pseudonoise signal sequence such that said phase of said pseudonoise signal sequence generated by said local generator means is locked to the phase of the pseudonoise signal component of the received spread spectrum signal.

Claim 14

In a receiver for a spread specturm encoded signal wherein the received spread spectrum signal includes a carrier signal that has been phase modulated by a data signal and by a pseudonoise signal, a detector comprising: first channel means; second channel means; means for applying the received spread spectrum signal to said first and second channel means; local generator means for generating a pseudonoise sequence signal having phase transitions which corresponds to the pseudonoise signal component of the received spread spectrum signal; said first channel means including demodulation means for correlating the pseudonoise signal component of the received spread spectrum signal with said pseudonoise sequence signal generated by said local generator means to thereby generate a detected recovered signal; means for detecting the polarity of said phase transitions of said pseudonoise reference signal and for generating a differential PN signal; means for correlating the received spread spectrum encoded signal and said error signal to thereby generate a recovered error signal; and means for correlating said detected recovered signal and said recovered error signal to therby generate a control signal for application to said local generator means, wherein said control signal controls the phase of said pseudonoise signal sequence such that said phase of said pseudonoise signal sequence generated by said local generator means is locked to the phase of the pseudonoise signal component of the received spread spectrum signal.

Claim 15

The detector of claim 12 wherein said local generator means further includes: voltage controlled oscillator means responsive to said control signal for clocking said local generator means.

Claim 16

The detector of claim 12 wherein said means for determining the polarity of said phase transitions of said pseudonoise sequence signal comprises: means for differentiating the pseudonoise sequence signal.

Claim 17

The detector of claim 14 wherein said means for differentiating includes double balance mixer means.

Claim 18

The detector of claim 12 wherein said first channel means further includes: data filter means for filtering said detected recovered signal.

Claim 19

The detector of claim 12 wherein said second channel means further includes: filter means for filtering said recovered error signal.

Claim 20

The detector of claim 12 wherein said means for determining the polarity of said phase transitions of said pseudonoise sequence signal samples each pseudonoise sequence bit of said pseudonoise sequence signal to determine polarity transitions between pseudonoise sequence bits.

Claim 21

The detector of claim 12 wherein said means for determining the polarity of said phase transitions of said pseudonoise sequence signal samples every other pseudonoise sequence bit of said pseudonoise sequence signal to determine polarity transitions between successive pairs of pseudonoise sequence bits.

Claim 22

The detector of claim 12 wherein said means for determining the polarity of said phase transitions of said pseudonoise sequence signal samples a plurality of pseudonoise sequence bits of said pseudonoise sequence signal to determine polarity transitions between multiple pseudonoise sequence bits.

Claim 23

A detector for use in a communication receiver for a spread spectrum signal wherein the signal is modulated by a data signal and by a pseudonoise signal and detected by a locally generated pseudonoise reference signal, comprising: data channel means; error channel means; means for applying the spread spectrum signal to said data channel means and to said error channel means; voltage controlled oscillator means for generating a local pseudonoise sequence signal having phase transitions which correspond to the pseudonoise signal component of the spread spectrum signal; said data channel means including demodulation means for removing the pseudonoise signal component of the spread spectrum signal in response to said local pseudonoise sequence signal to thereby generate a partially recovered signal; filter means for receiving said partially recovered signal and for generating a recovered signal; differentiating means for determining phase transitions in said local pseudonoise sequence signal and for generating a differential PN signal in response to detected phase transitions; said error channel means including first mixer means for correlating the spread spectrum signal and said differential PN signal to generate a recovered error signal; said error channel means including filter means for filtering said recovered error signal; second mixer means for synchronizing the phase of said recovered error signal with the phase of the recovered signal and for removing the data signal component of said error signal to thereby generate a control signal; and means for applying said control signal to said voltage controlled oscillator means for locking said pseudonoise sequence signal generated by said voltage controlled oscillator means to the pseudonoise signal component of the spread spectrum signal.

Claim 24

A detector for use in a communication receiver for a spread spectrum signal wherein the signal is modulated by a data signal and by a pseudonoise signal and detected by a locally generated pseudonoise reference signal, comprising: data channel means; error channel means; means for applying the spread spectrum signal to said data channel means and to said error channel means; voltage controlled oscillator means for generating a local pseudonoise sequence signal having phase transitions which correspond to the pseudonoise signal component of the spread spectrum signal; said data channel means including demodulation means for removing the pseudonoise signal component of the spread spectrum signal in response to said local pseudonoise sequence signal to thereby generate a partially recovered signal; filter means for receiving said partially recovered signal and for generating a recovered signal; differentiating means for determining phase transitions in said local pseudonoise sequence signal and for generating a differential PN signal in response to detected phase transitions; said error channel means including first mixer means for correlating the spread spectrum signal and said differential PN signal to generate a recovered error signal; said error channel means including filter means for filtering said recovered error signal; second mixer means for synchronizing the phase of said recovered error signal with the phase of the recovered signal and for removing the data signal component of said error signal to thereby generate a control signal; and means for applying said control signal to said voltage controlled oscillator means for locking said pseudonoise sequence signal generated by said voltage controlled oscillator means to the pseudonoise signal component of the spread spectrum signal.

Claim 25

The detector of claim 21 wherein said demodulation means includes: double balance mixer means.

Claim 26

The detector of claim 21 wherein said differentiating means includes: double balance mixer means.

Claim 27

The detector of claim 21 wherein said means for applying said control signal to said voltage controlled oscillator means includes: means for filtering said control signal; and clock means for receiving said filtered control signal to clock said voltage controlled oscillator means.

Claim 28

The detector of claim 21 wherein said spread spectrum signal comprises a baseband frequency signal.

Claim 29

The detector of claim 21 wherein said spread spectrum signal comprises an intermediate frequency signal and said means for applying the spread spectrum signal to said data channel means and said error channel means includes means for translating said intermediate frequency prior to application to said channel means.

Claim 30

The detector of claim 21 and further including: mean for delaying the application of said local pseudonoise sequence signal to said differentiating means by a predetermined number of pseudonoise sequence bits, such that the present pseudonoise sequence bit and the next succeeding pseudonoise sequence bit are applied to said differentiating means.

Claim 31

The detector of claim 27 wherein said means for delaying the application of said local pseudonoise sequence signal delays said local pseudonoise sequence signal by one pseudonoise sequence bit.

Claim 32

The detector of claim 21 and further including: mean for delaying the application of said error signal to said first mixer means by a predetermined number of pseudonoise sequence bits, such that a transition in said local pseudonoise sequence signal occurs within a pulse width of said error signal.

Claim 35

The method of claim 30 and further including: filtering the control signal.

Claim 36

The method of claim 30 and further including: generating a pseudonoise sequence signal which corresponds to a pseudonoise signal component of the received data signal.

Claim 37

The method of claim 30 wherein the step of detecting the polarity transitions in the local reference signal includes differentiating the local reference signal.

Claim 38

The method of claim 30 and further including: filtering the recovered data signal prior to correlation with the error signal.

Claim 39

The method of claim 30 and further including: filtering the error signal prior to correlation with the recovered data signal.