RECEIVERS AND DEMODULATORS FOR TDMA AND OTHER MODULATED SYTEMS

• US 20070053472A1
• Filed: 10/25/2006
• Published: 03/08/2007
• Est. Priority Date: 08/10/1998
• Status: Active Grant

• Current Assignee: Quarterhill Inc. (f/k/a Wi-LAN Inc.)
• Original Assignee: Wi-LAN Inc.
• Inventors: Feher, Kamilo
• Granted Patent: US 7,426,248 B2
• Time in Patent Office: Days
• US Class Current: 375/347
• CPC Class Codes: H04B 1/69 Spread spectrum techniques
• CPC Class Codes: H04B 2201/70703 using multiple or variable rates
• CPC Class Codes: H04B 2201/70707 Efficiency-related aspects
• CPC Class Codes: H04B 7/0602 using antenna switching H04B7/0686 takes precedence; antenna beam directivity switching H01Q3/24
• CPC Class Codes: H04B 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion
• CPC Class Codes: H04L 1/205 jitter monitoring
• CPC Class Codes: H04L 2025/03407 Continuous phase
• CPC Class Codes: H04L 2025/03414 Multicarrier
• CPC Class Codes: H04L 2025/03477 not time-recursive
• CPC Class Codes: H04L 25/03025 using a two-tap delay line
• CPC Class Codes: H04L 25/0305 using blind adaptation
• CPC Class Codes: H04L 25/0307 using blind adaptation
• CPC Class Codes: H04L 25/4902 Pulse width modulation; Pulse position modulation
• CPC Class Codes: H04L 27/00 Modulated-carrier systems
• CPC Class Codes: H04L 27/0004 using wavelets
• CPC Class Codes: H04L 27/0008 arrangements for allowing a transmitter or receiver to use more than one type of modulation negotiating modulation type for two-way transmission paths H04L5/1453
• CPC Class Codes: H04L 27/01 Equalisers baseband equalizers at the transmitter end H04L25/03343; in analogue transmission systems H04B3/04, H04B7/005
• CPC Class Codes: H04L 27/18 Phase-modulated carrier systems, i.e. using phase-shift keying H04L27/32 takes precedence
• CPC Class Codes: H04L 27/186 in which the information is carried by both the individual signal points and the subset to which the individual signal points belong, e.g. coset coding or related schemes
• CPC Class Codes: H04L 27/2017 in which the phase changes are non-linear, e.g. generalized and Gaussian minimum shift keying, tamed frequency modulation H04L27/201 takes precedence
• CPC Class Codes: H04L 27/2637 : with direct modulation of individual subcarriers
• CPC Class Codes: H04L 27/34 : Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
• CPC Class Codes: H04L 5/0008 : Wavelet-division
• CPC Class Codes: H04L 5/0016 : Time-frequency-code
• CPC Class Codes: H04L 5/0028 : Variable division signaling therefor H04L5/0092
• CPC Class Codes: H04L 7/0008 : Synchronisation information channels, e.g. clock distribution lines

Abstract

Receiver network for receiving a first filtered modulated transmitted signal in a first RF band and a second modulated transmitted signal in a second RF band and for providing received signals to one or more demodulators. A demodulator and baseband filter for demodulating and filtering the first filtered modulated received signal and for providing filtered demodulated baseband signal by a baseband filter mis-matched to the filter of the first filtered modulated transmitted signal and demodulating the second modulated signal providing a demodulated baseband signal and a selector for selecting either the first or the second demodulated baseband signal. A receiver and demodulation system receiving a first TDMA modulated signal having a first bit rate and for receiving a second modulated signal having a second bit rate and for providing the received signals to a one or more demodulators and for providing cross-correlated demodulated in-phase and quadrature-phase baseband signals and demodulating the second bit rate modulated signal and providing a demodulated baseband signal.

Claims

1. A receiver and demodulation system comprising:

a receiver network for receiving a first filtered modulated transmitted signal in a first RF band and a second modulated transmitted signal in a second RF band and for providing said first and second received signals to a demodulator;

a demodulator and baseband filter for demodulating and filtering the first filtered modulated received signal and for providing filtered demodulated baseband signal by said baseband filter which is mis-matched to the filter of the said first filtered modulated transmitted signal and demodulating the second modulated signal providing a demodulated baseband signal; and

a selector for selecting either the first or the second demodulated baseband signal.

4. The system as in claim 1 wherein the demodulator demodulating the first modulated signal provides filtered cross-correlated in-phase and quadrature phase baseband signals.

5. The system as in claim 1 wherein the first or the second modulated signal is an Orthogonal Frequency Division Multiplexed (OFDM) modulated signal.

6. The system as in claim 1 wherein the first or the second modulated signal is a TDM or TDMA modulated signal.

7. The demodulation system as in claim 1 wherein the first or the second modulated signal is a spread spectrum modulated signal.

8. The demodulation system as in claim 1 wherein the first modulated signal is a Gaussian Minimum Shift Keying (GMSK) or a Frequency Shift Keying (FSK) modulated signal and the second modulated signal is a spread spectrum modulated signal.

9. The system as in claim 1 wherein the first or the second modulated signal is a Phase Shift Keying (PSK) modulation, or an Offset OQPSK (OQPSK) or a Quadrature Modulation (QM), or a Frequency Modulation (FM) modulated signal.

2. A receiver and demodulation system comprising:

a receiver network for receiving a first TDMA modulated signal having a first bit rate and for receiving a second modulated signal having a second bit rate and for providing the received signals to a demodulator;

a demodulator demodulating the first modulated signal and providing cross-correlated demodulated in-phase and quadrature-phase baseband signals and demodulating the second bit rate modulated signal and providing a demodulated baseband signal; and

a selector for selecting either the first or the second demodulated signals.

10. The system as in claim 2 wherein the first or the second modulated signal is a TDM or a TDMA modulated signal.

11. The demodulation system as in claim 2 wherein the first or the second modulated signal is an Orthogonal Frequency Division Multiplexed (OFDM) modulated signal.

12. The demodulation system as in claim 2 wherein the first or the second modulated signal is a spread spectrum modulated signal.

13. The demodulation system as in claim 2 wherein the first or the second modulated signal is a Phase Shift Keying (PSK) modulation, or a Quadrature Modulation (QM), or a Frequency Modulation (FM) modulated signal.

3. A receiver and demodulation system comprising:

a receiver network for receiving a first TDM or TDMA modulated signal having a first modulation format, first bit rate and first RF spectrum and for receiving a second modulated signal having a second modulation format, second bit rate and second RF spectrum and for providing the received signals to a demodulator system;

a demodulator system comprising two or more demodulators for demodulating the first modulated signal and providing cross-correlated demodulated in-phase and quadrature-phase baseband signals and demodulating the second modulated signal and providing a demodulated baseband signal; and

a selector for selecting either the first or the second demodulated signal.

14. The receiver and demodulation system as in claim 3 wherein the first demodulator is comprised of mismatched filters which are mismatched to that of the filters of the modulator providing the first modulated signal.

15. The system as in claim 3 wherein the first or the second modulated signal is a TDM or a TDMA modulated signal.

16. The receiver and demodulation system as in claim 3 wherein the second modulated signal is an Orthogonal Frequency Division Multiplexed (OFDM) modulated signal.

17. The receiver and demodulation system as in claim 3 wherein the first or the second modulated signal is a spread spectrum modulated signal.