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

• US 6,928,101 B2
• Filed: 06/26/2002
• Issued: 08/09/2005
• Est. Priority Date: 01/09/1995
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Feher, Kamilo
• Primary Examiner(s): Le, Amanda T.
• Application Number:
  US10/180,234
• Publication Number:
  US 20020181547A1
• Time in Patent Office: 1,140 Days
• Field of Search: 375/140, 375/141, 375/146, 375/261, 375/130, 375/298
• 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 pi/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 pi/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. An apparatus, comprising:

a cross-correlator to receive in-phase and a quadrature signals to provide cross-correlated in-phase and quadrature signals; and

a spreader to spread the in-phase signal prior to the in-phase signal being received by said cross-correlator.

2. An apparatus as claimed in claim 1, further comprising a switch to activate the spreader in a first mode, and to deactivate the spreader in a second mode.

3. An apparatus as claimed in claim 1, further comprising a quadrature modulator to modulate the cross-correlated in-phase and quadrature signals.

4. An apparatus as claimed in claim 1, further comprising a switch to activate the spreader in a first mode, and to deactivate the spreader in a second mode, and a quadrature modulator to modulate the cross-correlated in-phase and quadrature signals.

5. An apparatus, comprising:

a cross-correlator to receive an in-phase and a quadrature signal to provide cross-correlated in-phase and quadrature signals; and

a spreader to spread the quadrature signal prior to the in-phase signal being received by said cross-correlator.

6. An apparatus as claimed in claim 5, further comprising a switch to activate the spreader in a first mode, and to deactivate the spreader in a second mode.

7. An apparatus as claimed in claim 5, further comprising a quadrature modulator to modulate the cross-correlated in-phase and quadrature signals.

8. An apparatus as claimed in claim 5, further comprising a switch to activate the spreader in a first mode, and to deactivate the spreader in a second mode, and a quadrature modulator to modulate the cross-correlated in-phase and quadrature signals.

9. An apparatus, comprising:

a cross-correlator to receive an in-phase and a quadrature signal to provide cross-correlated in-phase and quadrature signals; and

a first spreader to spread the in-phase signal prior to the in-phase signal being received by said cross-correlator; and

a second spreader to spread the quadrature signal prior to the quadrature signal being received by said cross-correlator.

10. An apparatus as claimed in claim 9, further comprising a switch to activate the first spreader in a first mode, and to deactivate the first spreader in a second mode.

11. An apparatus as claimed in claim 9, further comprising a switch to activate the second spreader in a first mode, and to deactivate the second spreader in a second mode.

12. An apparatus as claimed in claim 9, further comprising a first switch to activate and deactivate the first spreader, and a second switch to activate and deactivate the second spreader.

13. An apparatus as claimed in claim 9, further comprising a first switch to activate and deactivate the first spreader, and a second switch to activate and deactivate the second spreader, said first and second switches to provide at least one or more modes of operation.

14. An apparatus as claimed in claim 9, further comprising a quadrature modulator to modulate the cross-correlated in-phase and quadrature signals.

15. An apparatus as claimed in claim 9, further comprising a switch to activate the first spreader in a first mode, and to deactivate the first spreader in a second mode, and further comprising a quadrature modulator to modulate the cross-correlated in-phase and quadrature signals.

16. An apparatus as claimed in claim 9, further comprising a switch to activate the second spreader in a first mode, and to deactivate the second spreader in a second mode, and further comprising a quadrature modulator to modulate the cross-correlated in-phase and quadrature signals.

17. An apparatus as claimed in claim 9, further comprising a first switch to activate and deactivate the first spreader, and a second switch to activate and deactivate the second spreader, and further comprising a quadrature modulator to modulate the cross-correlated in-phase and quadrature signals.

18. An apparatus as claimed in claim 9, further comprising a first switch to activate and deactivate the first spreader, and a second switch to activate and deactivate the second spreader, said first and second switches to provide at least one or more modes of operation, and further comprising a quadrature modulator to modulate the cross-correlated in-phase and quadrature signals.