FMOD transceivers including continuous and burst operated TDMA, FDMA, spread spectrum CDMA, WCDMA and CSMA

• US 5,784,402 A
• Filed: 02/12/1996
• Issued: 07/21/1998
• Est. Priority Date: 01/09/1995
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Kamilo Feher
• Inventors: Feher, Kamilo
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Le, Amanda T.
• Application Number:
  US08/601,429
• Time in Patent Office: 890 Days
• Field of Search: 375/200, 375/208-210, 375/260, 375/216, 375/261, 375/296, 375/298, 375/324, 375/340, 375/349, 332/100-105
• US Class Current: 375/130
• CPC Class Codes: H03C 3/005 Circuits for asymmetric modulation
• CPC Class Codes: H04L 27/2032 for discrete phase modulation, e.g. in which the phase of the carrier is modulated in a nominally instantaneous manner
• CPC Class Codes: H04L 27/362 Modulation using more than one carrier, e.g. with quadrature carriers, separately amplitude modulated H04L27/366 takes precedence
• CPC Class Codes: H04L 27/38 Demodulator circuits; Receiver circuits

Abstract

Binary and Quadrature Feher'"'"'s Modulation (F-Modulation, or FMOD) Transmitter-Receiver systems and circuits exhibit reduced envelope fluctuation and peak radiation, and increased efficiency. A subclass of these systems has a constant envelope. They advantageously provide lower power operation with improved performance including robust BER performance, and compatibility with both linearly and nonlinearly amplified narrow spectrum, and without disadvantages of conventional BPSK, DBPSK QPSK and π/4-QPSK. Feher'"'"'s BPSK (FBPSK) is an improved efficiency transmitter which is compatible with conventional BPSK receivers. FBPSK modems are based on using quadrature structure where Q-channel data is inserted in quadrature with I-channel data for certain applications. The Q-channel data may be "offset" from the I-channel data by an amount selectable between zero and a specified time. Further improvement in the spectrum is attained using correlation between I and Q channels. FBPSK modem is shown to meet the IEEE 802.11 specified spectral direct sequence spread spectrum mask (-30 dB point) for wireless LAN, and leads to an output power gain of 6.5 dB over conventional BPSK modems. The cross-coupled quadrature FMOD structure is also suitable for continuous mode and for burst operated TDMA, FDMA, CDMA, WCDMA and CSMA Frequency Modulation Quadrature AM (QAM), QPSK and offset QPSK, as well as π/4-shifted QPSK modems/processors. Reduced modulation index Gaussian FSK (GFSK), multilevel FM and cross-coupled Quadrature Amplitude Modulated (QAM) transmitters and combinations of these modulations and corresponding coherent demodulators are disclosed. Controlled rise and fall time descriptions of burst operated systems are included.

Claims

1. A structure comprising:

an input port for receiving input data;

a splitter having an input coupled to said input port, and serving to process said input data by splitting said input data into split baseband signals;

a baseband signal processing network for receiving said split baseband signals streams and providing cross-correlated processed in-phase and quadrature-phase baseband signals; and

a spreading circuit for spreading the split cross-correlated processed baseband signals.

2. A structure as in claim 1 which further comprises a quadrature modulator receiving said processed in-phase and quadrature-phase baseband signals and providing a quadrature modulated output signal.

3. A structure as in claim 2 in which said quadrature modulator is connected between said cross-correlated processor and said spreading circuit.

4. A structure as in claim 2 in which said quadrature modulator is connected to an output of said spreading circuit.

5. A cross correlated quadrature architecture signal processor for producing cross correlated in phase and quadrature phase signal streams for modulation by a Quadrature Modulator comprising:

a filter for receiving an input signal selected from the group of binary, multi-level, and analog signals and combinations thereof and producing a filtered input signal;

signal shaping means for integrating said filtered input signal;

an amplifier for varying the modulation index of said signal processor, said amplifier receiving said filtered input signal and providing an amplified input signal;

a splitter receiving said amplified input signal and providing cross correlated data streams; and

a signal processor having an in phase and quadrature phase channel each receiving one of said cross correlated data streams, each of said in phase and quadrature phase channel having a first delay gain filter, means for generating linearly and/or nonlinearly values for said in phase and quadrature phase channel datastream, a wave shaper and a second delay gain filter, such that said signal processor provides in phase and quadrature phase cross correlated data signals for quadrature modulation with a modulated signal adaptable for coherent demodulation of the quadrature frequency modulated (FM) signal.

6. A cross correlated quadrature architecture signal processor for producing cross correlated in-phase and quadrature-phase signals for modulation by a quadrature modulator and subsequent demodulation of the quadrature modulated signals comprising:

a splitter for receiving an input signal and providing a pair of in-phase and quadrature-phase data signals; and

a signal processor having an in-phase channel and a quadrature-phase channel each said channel receiving one of said pair of data signals, each of said channels including;

a time delay element for receiving said one of said pair of data signals and producing a time delayed data signal having a time delay in the range of zero time delay to a specified value of time delay, said time delay for said in-phase channel being selectable independently of said time delay for said quadrature-phase channel;

an amplifier for receiving said delayed data signal and producing an amplified data signal; and

a filter for receiving said amplified data signal and producing a filtered data signal;

such that said cross correlated quadrature architecture signal processor provides in-phase and quadrature-phase cross correlated data signals for quadrature modulation with a modulated signal suitable for amplification in linear and non-linear mode and adaptable for demodulation.

7. A cross correlated quadrature architecture signal processor as in claim 6, wherein said input signal received by said splitter is selected from the group consisting of binary signals, multi-level signals, analog signals, and combinations thereof.

8. A cross correlated quadrature architecture signal processor as in claim 6, wherein said splitter provides identical in-phase and quadrature-phase data signals.

9. A cross correlated quadrature architecture signal processor as in claim 6, wherein said modulation and said demodulation are selected from the group consisting of binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), π

/4-QPSK, differential binary phase shift keying (DBPSK), differential quadrature phase shift keying (DQPSK), offset quadrature phase shift keying (OQPSK), and quadrature amplitude modulated (QAM) signals.

10. A cross correlated quadrature architecture signal processor as in claim 6, wherein said subsequent demodulation of the quadrature modulated signal is demodulation selected from the group consisting of binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), π

/4-QPSK, and offset quadrature phase shift keying (OQPSK).

11. A cross correlated quadrature architecture signal processor as in claim 6, wherein said time delay for each of said in-phase channel and said quadrature-phase channel is zero time delay.