Spatio-temporal processing for interference handling

• US 6,452,981 B1
• Filed: 11/05/1999
• Issued: 09/17/2002
• Est. Priority Date: 08/29/1996
• Status: Expired due to Term

• Current Assignee: Cisco Systems, Inc.
• Original Assignee: Cisco Systems, Inc.
• Inventors: Raleigh, Gregory G., Pollack, Michael A., Jones, Vincent K. IV
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Fan, Chieh M.
• Application Number:
  US09/435,293
• Time in Patent Office: 1,047 Days
• Field of Search: 375/219, 375/260, 375/285, 375/296, 375/299, 375/316, 375/346, 375/347, 375/348, 375/349, 375/350, 370/203, 370/220, 370/342, 455/63, 455/64, 455/65, 708/403, 708/404, 708/405
• US Class Current: 375/299
• CPC Class Codes: H04B 1/1081 Reduction of multipath noise by equalising H04B7/005
• CPC Class Codes: H04B 7/0443 utilizing "waterfilling" technique
• CPC Class Codes: H04B 7/0469 taking special antenna structures, e.g. cross polarized antennas into account
• CPC Class Codes: H04B 7/0615 of weighted versions of same signal
• CPC Class Codes: H04B 7/0619 using feedback from receiving side feedback signaling for adaptive modulation/coding H04L1/0001
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/0658 Feedback reduction
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• CPC Class Codes: H04B 7/068 using space frequency diversity space-frequency coding H04L1/0606
• CPC Class Codes: H04B 7/0842 Weighted combining
• 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: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0054 Maximum-likelihood or sequential decoding, e.g. Viterbi, Fano, ZJ algorithms
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/006 Trellis-coded modulation
• CPC Class Codes: H04L 1/0065 Serial concatenated codes
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/0606 Space-frequency coding
• CPC Class Codes: H04L 1/0618 : Space-time coding
• CPC Class Codes: H04L 1/18 : Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 1/1812 : Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 2025/03414 : Multicarrier
• CPC Class Codes: H04L 2025/03426 : transmission using multiple-input and multiple-output channels
• CPC Class Codes: H04L 2025/03802 : Signalling on the reverse channel
• CPC Class Codes: H04L 25/0204 : of multiple channels
• CPC Class Codes: H04L 25/021 : Estimation of channel covariance
• CPC Class Codes: H04L 25/0212 : of impulse response
• CPC Class Codes: H04L 25/0242 : using matrix methods
• CPC Class Codes: H04L 25/03305 : Joint sequence estimation and interference removal joint detection of several desired signals H04L25/03331
• CPC Class Codes: H04L 25/03331 : Arrangements for the joint estimation of multiple sequences
• CPC Class Codes: H04L 25/03343 : Arrangements at the transmitter end
• CPC Class Codes: H04L 27/2601 : Multicarrier modulation systems
• CPC Class Codes: H04L 27/2626 : Arrangements specific to the transmitter only
• CPC Class Codes: H04L 27/2647 : Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04L 5/0007 : the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0023 : Time-frequency-space
• CPC Class Codes: H04L 5/0028 : Variable division signaling therefor H04L5/0092
• CPC Class Codes: H04L 5/0046 : Determination of how many bits are transmitted on different sub-channels
• CPC Class Codes: H04W 16/28 : using beam steering
• CPC Class Codes: H04W 72/00 : Local resource management
• CPC Class Codes: H04W 88/02 : Terminal devices
• CPC Class Codes: H04W 88/08 : Access point devices

Abstract

A space-time signal processing system with advantageously reduced complexity. The system may take advantage of multiple transmitter antenna elements and/or multiple receiver antenna elements, or multiple polarizations of a single transmitter antenna element and/or single receiver antenna element. The system is not restricted to wireless contexts and may exploit any channel having multiple inputs or multiple outputs and certain other characteristics. Multi-path effects in a transmission medium cause a multiplicative increase in capacity.

Claims

1. A transmitter system for transmitting via a plurality of inputs to a channel, said transmitter system comprising:

at least one processing element that applies a time domain substantially orthogonalizing procedure to divide said channel into input bins;

a spatial processor employing weightings among said channel inputs to define spatial directions wherein each input bin has at least one associated spatial direction; and

wherein said transmitter system transmits information in subchannels of said channel, each of said subchannels being defined by a combination of input bin and spatial direction, by employing said at least one processing element for at least two independent applications of said time domain substantially orthogonalizing procedure; and

wherein

said weightings are chosen to minimize interference to unintended receivers.

2. A transmitter system for transmitting via a plurality of inputs to a channel, said transmitter system comprising:

at least one processing element that applies a time domain substantially orthogonalizing procedure to divide said channel into input bins;

a spatial processor employing weightings among said channel inputs to define spatial directions wherein each input bin has at least one associated spatial direction; and

wherein said transmitter system transmits information in subchannels of said channel, each of said subchannels being defined by a combination of input bin and spatial direction, by employing said at least one processing element for at least two independent applications of said time domain substantially orthogonalizing procedure; and

wherein

said weightings are chosen based on characterization of an undesired signal subspace and a desired signal subspace.

3. The transmitter system of claim 2 wherein said characterizations of said desired signal subspace and said undesired signal subspace are averaged over at least one of time and frequency.

4. A transmitter system for transmitting via a plurality of inputs to a channel, said transmitter system comprising:

at least one processing element that applies a time domain substantially orthogonalizing procedure to divide said channel into input bins;

a spatial processor employing weightings among said channel inputs to define spatial directions wherein there are at least two spatial directions; and

wherein said transmitter system transmits information in subchannels of said channel, each of said subchannels being defined by a combination of input bin and spatial direction, by employing said at least one processing element for at least two independent applications of said time domain substantially orthogonalizing procedure and wherein said at least two spatial directions are the same for all of said input bins.

5. The transmitter system of claim 4 further comprising:

a system input that receives a group of input symbols wherein each input symbol corresponds to a particular input bin of said time domain substantially orthogonalizing procedure and a particular one of said at least two spatial directions; and

wherein

said at least one processing element applies said time domain substantially orthogonalizing procedure to said group of input symbols independently to symbols corresponding to each of said at least two spatial directions; and

wherein

said spatial processor, for each independent application of said time domain substantially orthogonalizing procedure, applies one of said weightings to output of said time domain substantially orthogonalizing procedure, each of said weightings being defined by the particular spatial direction associated with each application of said time domain orthogonalizing procedure and being the same for each output bin of said time domain substantially orthogonalizing procedure.

6. A transmitter system for transmitting via a plurality of inputs to a channel, said transmitter system comprising:

at least one processing element that applies a time domain substantially orthogonalizing procedure to divide said channel into input bins;

a spatial processor employing weightings among said channel inputs to define spatial directions wherein there are at least two spatial directions;

wherein said transmitter system transmits information in subchannels of said channel, each of said subchannels being defined by a combination of input bin and spatial direction, by employing said at least one processing element for at least two independent applications of said time domain substantially orthogonalizing procedure;

wherein said spatial processor, for each of said spatial directions applies one of said weightings to define contributions to each of said channel inputs; and

wherein said at least one processing element independently applies said substantially orthogonalizing procedure to output of said spatial processor independently for each of said channel inputs;

an encoder that applies a coding procedure to inputs to said spatial processor; and

wherein said coding procedure is applied independently for each of said input bins.

7. A transmitter system for transmitting via a plurality of inputs to a channel, said transmitter system comprising:

at least one processing element that applies a time domain substantially orthogonalizing procedure to divide said channel into input bins;

a spatial processor employing weightings among said channel inputs to define spatial directions wherein there are at least two spatial directions;

wherein said transmitter system transmits information in subchannels of said channel, each of said subchannels being defined by a combination of input bin and spatial direction, by employing said at least one processing element for at least two independent applications of said time domain substantially orthogonalizing procedure;

wherein said spatial processor, for each of said spatial directions applies one of said weightings to define contributions to each of said channel inputs; and

wherein said at least one processing element independently applies said substantially orthogonalizing procedure to output of said spatial processor independently for each of said channel inputs;

an encoder that applies a coding procedure to inputs to said spatial processor; and

wherein said coding procedure is applied independently for each of said spatial directions.

8. A transmitter system for transmitting via a plurality of inputs to a channel, said transmitter system comprising:

at least one processing element that applies a time domain substantially orthogonalizing procedure to divide said channel into input bins;

a spatial processor employing weightings among said channel inputs to define spatial directions wherein there are at least two spatial directions;

wherein said transmitter system transmits information in subchannels of said channel, each of said subchannels being defined by a combination of input bin and spatial direction, by employing said at least one processing element for at least two independent applications of said time domain substantially orthogonalizing procedure;

wherein said spatial processor, for each of said spatial directions applies one of said weightings to define contributions to each of said channel inputs; and

wherein said at least one processing element independently applies said substantially orthogonalizing procedure to output of said spatial processor independently for each of said channel inputs;

an encoder that applies a coding procedure to inputs to said spatial processor; and

wherein said coding procedure is applied independently for each of said subchannels.

9. A transmitter system for transmitting via a plurality of inputs to a channel, said transmitter system comprising:

at least one processing element that applies a time domain substantially orthogonalizing procedure to divide said channel into input bins;

a spatial processor employing weightings among said channel inputs to define spatial directions wherein there are at least two spatial directions;

wherein said transmitter system transmits information in subchannels of said channel, each of said subchannels being defined by a combination of input bin and spatial direction, by employing said at least one processing element for at least two independent applications of said time domain substantially orthogonalizing procedure;

wherein said spatial processor, for each of said spatial directions applies one of said weightings to define contributions to each of said channel inputs; and

wherein said at least one processing element independently applies said substantially orthogonalizing procedure to output of said spatial processor independently for each of said channel inputs;

an encoder that applies a coding procedure to inputs to said spatial processor; and

wherein said coding procedure comprises a turbo coding procedure.

10. A transmitter system for transmitting via a plurality of inputs to a channel, said transmitter system comprising:

at least one processing element that applies a time domain substantially orthogonalizing procedure to divide said channel into input bins;

a spatial processor employing weightings among said channel inputs to define spatial directions wherein there are at least two spatial directions;

wherein said transmitter system transmits information in subchannels of said channel, each of said subchannels being defined by a combination of input bin and spatial direction, by employing said at least one processing element for at least two independent applications of said time domain substantially orthogonalizing procedure;

wherein said spatial processor, for each of said spatial directions applies one of said weightings to define contributions to each of said channel inputs; and

wherein said at least one processing element independently applies said substantially orthogonalizing procedure to output of said spatial processor independently for each of said channel inputs;

an encoder that applies a coding procedure to inputs to said spatial processor; and

wherein said coding procedure belongs to a group consisting of;

convolutional coding, Reed-Solomon coding, CRC coding, block coding, and interleaving.

11. A receiver system for receiving via a plurality of outputs from a channel, said receiver system comprising:

at least one processing element that a time domain substantially orthogonalizing procedure to divide said channel into output bins;

a spatial processor employing weightings among said channel outputs to define spatial directions wherein each output bin has at least one associated spatial direction; and

wherein said receiver system receives information via subchannels of said channel, by employing at least two independent parallel applications of said substantially orthogonalizing procedure by said at least one processing element, each of said subchannels being defined by a combination of output bin and spatial direction;

and wherein said weightings are chosen to minimize interference from undesired transmitters.

12. A receiver system for receiving via a plurality of outputs from a channel, said receiver system comprising:

at least one processing element that a time domain substantially orthogonalizing procedure to divide said channel into output bins;

a spatial processor employing weightings among said channel outputs to define spatial directions wherein each output bin has at least one associated spatial direction; and

wherein said receiver system receives information via subchannels of said channel, by employing at least two independent parallel applications of said substantially orthogonalizing procedure by said at least one processing element, each of said subchannels being defined by a combination of output bin and spatial direction;

and wherein said weightings are chosen based on characterization of a desired signal subspace and an undesired signal subspace.

13. The transmitter system of claim 12 wherein said characterizations of said desired signal subspace and said undesired signal subspace are averaged over at least one of time and frequency.

14. A receiver system for receiving via a plurality of outputs from a channel, said receiver system comprising:

at least one processing element that applies a time domain substantially orthogonalizing procedure to divide said channel into output bins;

a spatial processor employing weightings among said channel outputs to define spatial directions wherein each output bin has at least one associated spatial direction; and

wherein said receiver system receives information via subchannels of said channel, by employing at least two independent parallel applications of said substantially orthogonalizing procedure by said at least one processing element, each of said subchannels being defined by a combination of output bin and spatial direction;

wherein said at least one processing element applies said substantially orthogonalizing procedure independently for each of said channel outputs;

wherein said spatial processor, for each of said spatial directions applies one of said weightings to output of said at least one processing element to define contributions from each of said channel outputs; and

a decoder that applies a decoding procedure to outputs from said spatial processor; and

wherein said decoding procedure is applied independently for each of said spatial directions.

15. A receiver system for receiving via a plurality of outputs from a channel, said receiver system comprising:

at least one processing element that applies a time domain substantially orthogonalizing procedure to divide said channel into output bins;

a spatial processor employing weightings among said channel outputs to define spatial directions wherein each output bin has at least one associated spatial direction; and

wherein said receiver system receives information via subchannels of said channel, by employing at least two independent parallel applications of said substantially orthogonalizing procedure by said at least one processing element, each of said subchannels being defined by a combination of output bin and spatial direction;

wherein said at least one processing element applies said substantially orthogonalizing procedure independently for each of said channel outputs;

wherein said spatial processor, for each of said spatial directions applies one of said weightings to output of said at least one processing element to define contributions from each of said channel outputs; and

a decoder that applies a decoding procedure to outputs from said spatial processor; and

wherein said decoding procedure is applied independently for each of said output bins.

16. A receiver system for receiving via a plurality of outputs from a channel, said receiver system comprising:

at least one processing element that applies a time domain substantially orthogonalizing procedure to divide said channel into output bins;

a spatial processor employing weightings among said channel outputs to define spatial directions wherein each output bin has at least one associated spatial direction; and

wherein said receiver system receives information via subchannels of said channel, by employing at least two independent parallel applications of said substantially orthogonalizing procedure by said at least one processing element, each of said subchannels being defined by a combination of output bin and spatial direction;

wherein said at least one processing element applies said substantially orthogonalizing procedure independently for each of said channel outputs;

wherein said spatial processor, for each of said spatial directions applies one of said weightings to output of said at least one processing element to define contributions from each of said channel outputs; and

a decoder that applies a decoding procedure to outputs from said spatial processor; and

wherein said decoding procedure is applied independently for each of said subchannels.

17. A receiver system for receiving via a plurality of outputs from a channel, said receiver system comprising:

at least one processing element that applies a time domain substantially orthogonalizing procedure to divide said channel into output bins;

a spatial processor employing weightings among said channel outputs to define spatial directions wherein each output bin has at least one associated spatial direction; and

wherein said receiver system receives information via subchannels of said channel, by employing at least two independent parallel applications of said substantially orthogonalizing procedure by said at least one processing element, each of said subchannels being defined by a combination of output bin and spatial direction;

wherein said at least one processing element applies said substantially orthogonalizing procedure independently for each of said channel outputs;

wherein said spatial processor, for each of said spatial directions applies one of said weightings to output of said at least one processing element to define contributions from each of said channel outputs; and

a decoder that applies a decoding procedure to outputs from said spatial processor; and

wherein said decoding procedure is based on one of;

convolutional coding, trellis coding, Reed-Solomon coding, CRC coding, block coding, and interleaving.

18. A receiver system for receiving via a plurality of outputs from a channel, said receiver system comprising:

at least one processing element that applies a time domain substantially orthogonalizing procedure to divide said channel into output bins;

a spatial processor employing weightings among said channel outputs to define spatial directions wherein each output bin has at least one associated spatial direction; and

wherein said receiver system receives information via subchannels of said channel, by employing at least two independent parallel applications of said substantially orthogonalizing procedure by said at least one processing element, each of said subchannels being defined by a combination of output bin and spatial direction;

wherein said at least one processing element applies said substantially orthogonalizing procedure independently for each of said channel outputs;

wherein said spatial processor, for each of said spatial directions applies one of said weightings to output of said at least one processing element to define contributions from each of said channel outputs;

a decoder that applies a decoding procedure to outputs from said spatial processor; and

wherein said decoding procedure is based on turbo coding.