Method for wireless information transfer

• US 6,466,609 B2
• Filed: 04/26/1999
• Issued: 10/15/2002
• Est. Priority Date: 11/01/1996
• Status: Expired due to Fees

• Current Assignee: Nanotron Gesellschaft Fur Mikrotechnik mbH
• Original Assignee: Nanotron Gesellschaft Fur Mikrotechnik mbH
• Inventors: Ianelli, Zbigniew, Koslar, Manfred
• Primary Examiner(s): PHU, PHUONG M
• Application Number:
  US09/297,182
• Publication Number:
  US 20010043656A1
• Time in Patent Office: 1,268 Days
• Field of Search: 375/139, 359/154
• US Class Current: 375/139
• CPC Class Codes: H03K 7/04 Position modulation, i.e. PPM
• CPC Class Codes: H03K 7/06 Frequency or rate modulation, i.e. PFM or PRM
• CPC Class Codes: H04B 1/69 Spread spectrum techniques
• CPC Class Codes: H04B 2001/6912 using chirp

Abstract

Method for wireless information transfer, in particular for mobile communications, in which an input signal (s₁, g₄) is subjected to a modulation in a transmitter (2 to 8) and reaches a receiver (11 to 15) through a transmission channel, whereby angle modulated pulses, carrying information and possessing a frequency spectrum, are generated in the transmitter in such a way that they can be time compressed in a receiver by means of a filter (13) with frequency dependent, differential delay time, also known as group delay, in such a way, that pulses arise with shortened duration and increased amplitude compared to the emitted pulses, and at least a portion of the information is imprinted onto the pulses using an additional modulation, independent of the angle modulation, arid/or is used for controlling a parameter of the angle modulation that can then be registered in the receiver.

Claims

1. Method for wireless transmission of a digital signal, particularly for mobile communication, from a sender with antenna to a receiver with antenna, in which the signal is modulated in the sender and reaches the receiver via a transmission channel, characterized in that, in the sender, the digital signal is first converted into a quasi Dirac pulse sequence, wherein the frequency band of the quasi Dirac pulse sequence is limited by a low-pass filter such that the quasi Dirac pulse sequence is converted into a sequence of gap pulses whose form is described by the si function si(x)=^sinx/_x, which is subsequently modulated to a carrier frequency and then supplied to a dispersive filter for expansion, so that on the output side a frequency-modulated pulse sequence is output, wherein a transmitting pulse is time-compressed on the receiving side such that a pulse is created which has a shorter duration and increased amplitude compared to the transmitted pulses.

2. Method of claim 1 whereby

the pulses are filtered according to a default filter characteristic, whereby the angle modulation on the transmitter side and the group delay response of the dispersion filter on the receiver side are matched in such a way that the signal components of the angle modulated pulses of an output signal arrive at the output of the dispersion filter, due to the filter'"'"'s frequency dependent variable signal delay time, essentially coincident and, due to the superposition, with increases amplitude compared to the input.

3. Method of claim 1 whereby

an input signal possesses a carrier frequency, which is subjected pulse by pulse to an angle modulation in the transmitter.

4. Method of claim 1 whereby

the additional modulation method that imprints the information is, in particular, a pulse position modulation (PPM), or optionally a pulse code modulation (PCM), or a differential pulse code modulation (DPCM), or a pulse delta modulation (PDM), or a modification of one or several of these modulation methods.

5. Method of one of claim 2 whereby

the pulse sequence, angle modulated in the transmitter, is fed to a pair of dispersion filters in the receiver, whereby the pair of dispersion filters in the receiver possess different group delay responses which are matched in pairs to the modulation characteristic in such a way, that the signal components of the pulses arrive with increased amplitude at the output of only one of the pair of dispersion filters, while such an increase in amplitude does not take place for the other of the pair of dispersion filters, and the amplitudes are evaluated comparatively at the output of the pair of dispersion filters using a detector.

6. Method of claim 5 whereby

the angle—

the frequency or the phase—

of the carrier frequency changes, during the pulse duration of the pulse modulated signals, linearly with time, monotonically from a lower frequency or phase position to an upper frequency or phase position, or in reverse direction, and the dispersion filter in the receiver possesses a complementary linear response.

7. Method of claim 1 whereby

the modulation characteristics for the individual pulses of a series of pulses are selected differently in such a way that the differences contain part of the information.

8. Method of claim 1 whereby,

for matching of transmitter and receiver, a default digital reference signal is transmitted as input signal as alignment during the matching process,

during the matching process the amplitude or the pulse duration of the output signal of the dispersion filter on the receiver side is measured, and the modulation characteristic used on the transmitter side, or the group delay response of the dispersion filter on the receiver side, is varied, until the pulse duration reaches a minimum value, or the amplitude reaches a maximum value.

9. Sender-receiver arrangement comprising a sender for receiving and transmitting an input signal, wherein the sender has means for modulating the digital signal, and on the sender side, means for first converting the digital signal into a quasi Dirac pulse sequence, wherein a low pass filter on the sender side limits the frequency band of the quasi Dirac pulse sequence such that the quasi Dirac pulse sequence is converted into a sequence of gap pulses whose form is described by the si function si(x)=^sinx/_x, which is modulated to a carrier frequency by means of a corresponding modulator and is supplied to a dispersive filter on the sender side for expansion, so that the sender outputs a frequency-modulated pulse sequence on the output side, and, in the receiver, the pulse sequence is time-compressible by means of a filter with frequency-dependent differential propagation time, also referred to as group delay time, such that pulses are created which have a shorter duration and increased amplitude compared to the transmitting, frequency-modulated pulses.

10. Arrangement of claim 9 whereby

the first modulator generates a series of angle modulated pulses, whereby the angle modulation is carried out depending on the input signal at the control input, either according to a default first modulation characteristic or according to a second default modulation characteristic,

the receiver contains two dispersion filters connected in parallel, whereby the variable group delay response of the two dispersion filters and the first and second modulation characteristics are matched in such a way that the signal components of the angle modulated pulse sequence arrive time compressed and with increased amplitude at the output of exactly one of the two dispersion filters.

11. Arrangement of claim 9 whereby

the first modulator generates angle modulated pulses, whereby the angle modulation occurs independent of the input signal according to a default modulation characteristic, which determines the time variation of the frequency during the duration of each pulse, the second modulator on the transmitter side, for imprinting the information contained in the input signal, is an amplitude modulator, which determines the amplitude of the angle modulated pulses depending on the input signal,

the receiver for filtering of the pulses, angle modulated on the transmitter side according to the default modulation characteristic, contains exactly one dispersion filter with a default group delay response that is matched to the modulation characteristic used on the transmitter side in such a way that the signal components of each angle modulated pulse arrive time compressed and with increase in amplitude at the output of the dispersion filter on the transmitter side, and

a detector is connected after the dispersion filter on the transmitter side for recovery of the information contained in the input signal.

12. Arrangement of claim 9 whereby,

to allow alternating transmitting and receiving operation, the transmitter and the receiver contain corresponding, essentially identical component modules for modulation or demodulation, each containing at least one dispersion filter.

13. Method for wireless transfer of information, in particular for mobile communications, wherein an input signal is subjected to an angle modulation in a transmitter and reaches a receiver through a transmission channel, whereby

angle modulated pulses, possessing a frequency spectrum and carrying information, are generated in the transmitter in such a way, that they are time compressed in the receiver using a dispersion filter in the receiver with frequency dependent, differential delay time, also referred to as group delay, in such a way that pulses are created with shortened duration and increased amplitude, compared to the emitted pulses, and

at least a portion of the information in the transmitter is imprinted onto the pulses using an additional modulation, independent of the angle modulation, and/or is used for controlling a parameter of the angle modulation in the receiver, and

the modulation characteristic of the angle modulation determines the time variation of the phase angle during the duration of each pulse,

the amplitude of the angle modulated pulses in particular is used for the imprinting of the information contained in the input signal, depending on the input signal,

the group delay response of the dispersion filter in the receiver is complementary to the frequency-time characteristic of the transmission pulse, and

the amplitude of the pulse arriving compressed from the dispersion filter in the receiver is evaluated for recovery of the information contained in the input signal using a detector, in particular an amplitude demodulator,

the pulse sequence, angle modulated in the transmitter, is fed to a pair of dispersion filters in the receiver, whereby the pair of dispersion filters in the receiver possess different group delay responses which are matched in pairs to the modulation characteristic in such a way, that the signal components of the pulses arrive with increased amplitude at the output of only one of the dispersion filters in the receiver, while such an increase in amplitude does not take place for the other one of the dispersion filters in the receiver, and the amplitudes are evaluated comparatively at the output of the dispersion filters in the receiver using a detector, and whereby

the signal flow in the receiver is split into two parallel branches, each with two additional pairs of dispersion filters with group delay characteristics that are inverse with respect to each other, the signal flow in the two branches is connected through or interrupted for a predetermined time interval during each pulse, whereby the interruption or connection occurs synchronous with the transmission timing rate,

the two branches are joined on the output side by a subtracter.

14. Transmitter and receiver arrangement comprising

a transmitter, for pick-up and transmission of an input signal, whereby the transmitter contains a first modulator for angle modulation of the input signal, as well as a receiver, containing a demodulator for recovery of the input signal, whereby the first modulator generates angle modulated pulses according to a modulation characteristic that determines the time variation of the angle or phase position during the duration of each pulse,

the first modulator contains a control input for the pick-up of the input signal and for the setting of the modulation characteristic depending on the input signal, and/or the transmitter contains a second modulator for an additional modulation of the angle modulated pulses depending on the input signal,

the receiver contains a dispersion filter, in particular a surface acoustic wave filter, with a default group delay response for filtering the pulses, angle modulated on the transmitter side, according to the default modulation characteristic,

the group delay response of the dispersion filter in the receiver is matched, for an increase in amplitude of the output signal, to the modulation characteristic used on the transmitter side in such a way that the signal components of the pulses, angle modulated according to this modulation characteristic, arrive time compressed and with an amplitude enhancement at the output of the dispersion filter, due to the filter'"'"'s frequency dependent, variable signal delay time, and whereby

the receiver contains a noise suppression circuit, essentially consisting of two parallel branches, which are connected on the output side to the inputs of a subtracter, and in each of which two dispersion filters with group delay characteristics, inverse with respect to each other, are series connected, whereby in each of the two branches, between the two dispersion filters, a control element for controlling the signal flow is placed, which is connected to a synchronizing circuit for synchronization of the signal flow control with the transmission timing rate.

15. Transmitter and receiver arrangement comprising

a transmitter, for pick-up and transmission of an input signal, whereby the transmitter contains a first modulator for angle modulation of the input signal, as well as a receiver, containing a demodulator for recovery of the input signal, whereby

the first modulator generates angle modulated pulses according to a modulation characteristic that determines the time variation of the angle or phase position during the duration of each pulse,

the first modulator contains a control input for the pick-up of the input signal and for the setting of the modulation characteristic depending on the input signal, and/or the transmitter contains a second modulator for an additional modulation of the angle modulated pulses depending on the input signal,

the receiver contains a dispersion filter, in particular a surface acoustic wave filter, with a default group delay response for filtering the pulses, angle modulated on the transmitter side, according to the default modulation characteristic,

the group delay response of the dispersion filter in the receiver is matched, for an increase in amplitude of the output signal, to the modulation characteristic used on the transmitter side in such a way that the signal components of the pulses, angle modulated according to this modulation characteristic, arrive time compressed and with an amplitude enhancement at the output of the dispersion filter in the receiver, due to the filter'"'"'s frequency dependent, variable signal delay time,

the receiver contains a noise suppression circuit, essentially consisting of two parallel branches, which are connected on the output side to the inputs of a subtracter, and in each of which two dispersion filters with group delay characteristics, inverse with respect to each other, are series connected, whereby in each of the two branches, between the two dispersion filters in the noise suppression circuit, a control element for controlling the signal flow is placed, which is connected to a synchronizing circuit for synchronization of the signal flow control with the transmission timing rate, and whereby

the control element is a multiplier that, on the input side, is connected to the dispersion filter, connected before, and, for timed interruption or disconnection of the signal flow, with the synchronizing circuit.