Source: http://www.google.com/patents/US7359465?dq=6819670
Timestamp: 2014-07-13 10:01:49
Document Index: 634645680

Matched Legal Cases: ['Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60']

Patent US7359465 - Serial cancellation receiver design for a coded signal processing engine - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign in<nobr>Advanced Patent Search</nobr>PatentsA novel serial receiver for a wireless communication system is provided. The communication system comprises: a receiver for receiving a signal y having data parameters; a control processor; the control processor for receiving the signal y and the data parameters; at least two fingers, the control processor...http://www.google.com/patents/US7359465?utm_source=gb-gplus-sharePatent US7359465 - Serial cancellation receiver design for a coded signal processing engineAdvanced Patent SearchPublication numberUS7359465 B2Publication typeGrantApplication numberUS 11/103,138Publication dateApr 15, 2008Filing dateApr 11, 2005Priority dateSep 28, 2001Fee statusPaidAlso published asUS7158559, US8374299, US20040022302, US20050180496, US20110182330, WO2003060546A2, WO2003060546A3Publication number103138, 11103138, US 7359465 B2, US 7359465B2, US-B2-7359465, US7359465 B2, US7359465B2InventorsEric S. Olson, Anand P. Narayan, John K. ThomasOriginal AssigneeTensorcomm, IncExport CitationBiBTeX, EndNote, RefManPatent Citations (100), Non-Patent Citations (33), Classifications (25), Legal Events (7) External Links: USPTO, USPTO Assignment, EspacenetSerial cancellation receiver design for a coded signal processing engineUS 7359465 B2Abstract A novel serial receiver for a wireless communication system is provided. The communication system comprises: a receiver for receiving a signal y having data parameters; a control processor; the control processor for receiving the signal y and the data parameters; at least two fingers, the control processor for determining which of the data parameters are sent to respective fingers, wherein the at least two fingers have at least a search finger and a tracking finger; and wherein the tracking finger comprises a correlator and a Coded Signal Processing Engine (CSPE), the CSPE for interference cancellation in the reception of the signal y. In addition, numerous other embodiments of the serial receiver are provided along with methods for using the serial receiver.
1. A method for generating an interference cancelled signal, comprising:
A. providing for determining which of a plurality of input signals to utilize for generating an interference matrix to produce a plurality of selected signals;
B. providing for determining the order of cancellation of the said plurality of selected signals based at least in part on the strengths of the said plurality of selected signals; and
C. providing for sequentially cancelling the said plurality of selected signals from at least one of the said plurality of input signals to obtain an interference cancelled signal.
2. An apparatus configured for generating an interference cancelled signal, comprising:
a plurality of power estimators configured for computing power estimates of components of a received signal;
a control block coupled to the said plurality of power estimators configured to determine an order of cancellation of the said components of a received signal based at least in part on the said power estimates; and
a plurality of processing fingers coupled to the said control block configured for generating at least one interference cancelled signal stream.
3. The apparatus recited in claim 2 wherein the plurality of processing fingers comprises at least one Hadamard transform module configured to compute the amplitudes of a plurality of channels.
4. The apparatus recited in claim 2, wherein the said plurality of processing fingers comprises a de-spreader for despreading an input signal.
5. A method for generating an S matrix, comprising:
A. providing for determining which of a plurality of input signals to utilize for generating the S matrix to produce a plurality of selected input signals;
B. providing for multiplying each of the plurality of selected input signals with a projection matrix Ps ⊥ to generate a plurality of intermediate signals, each of the plurality of intermediate signals having an associated one of the plurality of selected input signals;
C. providing for determining a sign for each of the plurality of selected input signals;
D. providing for multiplying each of the plurality of intermediate signals with the sign of its associated one of the plurality of selected input signals to generate a plurality of columns of the S matrix; and
E. providing for storing the plurality of columns to form the S matrix.
6. The method recited in claim 5 wherein providing for determining the sign includes providing for utilizing relative amplitude information associated with the plurality of selected input signals to determine the sign.
7. An apparatus configured for generating an S matrix, comprising:
A. a selection means configured for determining which of a plurality of input signals to utilize for generating the S matrix to produce a plurality of selected input signals;
B. a first multiplication means configured for multiplying each of the plurality of selected input signals with a projection matrix Ps ⊥ to generate a plurality of intermediate signals, each of the plurality of intermediate signals having an associated one of the plurality of selected input signals;
C. a sign-determination means configured for determining a sign for each of the plurality of selected input signals;
D. a second multiplication means configured for multiplying each of the plurality of intermediate signals with the sign of its associated one of the plurality of selected input signals to generate a plurality of columns of the S matrix; and
E. a storage means configured for storing the plurality of columns to form the S matrix.
8. The apparatus recited in claim 7 wherein the sign-determination means is configured to utilize relative-amplitude information associated with the plurality of selected input signals to determine the sign.
9. The apparatus recited in claim 7, wherein the plurality of input signals comprises up to 64 input signals.
10. The apparatus recited in claim 7, wherein the first multiplication means further comprises a selective-engagement means configured for determining whether or not to multiply each of the plurality of selected input signals with the projection matrix Ps ⊥.
11. The apparatus recited in claim 7, wherein the second multiplication means further comprises a selective-engagement means configured for determining whether to multiply each of the plurality of intermediate signals with the sign of its associated one of the plurality of selected input signals.
12. A method for generating an S matrix comprising:
C. providing for determining a relative amplitude for each of the plurality of selected input signals;
D. providing for multiplying each of the plurality of intermediate signals with the relative amplitude of its associated one of the plurality of selected input signals to generate a plurality of columns of the S matrix; and
13. An apparatus configured for generating an S matrix comprising:
a selection means for determining which of a plurality of input signals to utilize for generating the S matrix to produce a plurality of selected input signals;
a first multiplication means configured for multiplying each of the plurality of selected input signals with a projection matrix Ps ⊥ to generate a plurality of intermediate signals, each of the plurality of intermediate signals having an associated one of the plurality of selected input signals;
an amplitude-determination means configured for determining a relative amplitude for each of the plurality of selected input signals;
a second multiplication means configured for multiplying each of the plurality of intermediate signals with the relative amplitude of its associated one of the plurality of selected input signals to generate a plurality of columns of the S matrix; and
a storage means configured for storing the plurality of columns to form the S matrix.
14. The apparatus recited in claim 13, wherein the plurality of input signals comprises up to 64 input signals.
15. The apparatus recited in claim 13, wherein the first multiplication means further comprises a selective-engagement means configured for determining whether or not to multiply each of the plurality of selected input signals with the projection matrix Ps ⊥.
16. The apparatus recited in claim 13, wherein the second multiplication means further comprises a selective-engagement means configured for determining whether to multiply each of the plurality of intermediate signals with the relative amplitude of its associated one of the plurality of selected input signals.
17. A method for generating an S matrix comprising:
B. providing for multiplying each of the plurality of selected input signals with a projection matrix Ps ⊥ to generate a first plurality of S-matrix columns and a plurality of intermediate signals, each of the plurality of intermediate signals having an associated one of the plurality of selected input signals;
C. providing for determining at least one of a sign and a relative amplitude for each of the plurality of selected input signals;
D. providing for multiplying each of the plurality of intermediate signals with at least one of the sign and the relative amplitude of its associated one of the plurality of selected input signals to generate a plurality of intermediate columns;
E. providing for summing the plurality of intermediate columns to generate at least one additional S-matrix column; and
F. providing for storing the first plurality of S-matrix columns and the at least one additional S-matrix column to form the S matrix.
18. An apparatus configured for generating an S matrix, comprising:
a selection means configured for determining which of a plurality of input signals to utilize for generating the S matrix to produce a plurality of selected input signals;
a first multiplication means configured for multiplying each of the plurality of selected input signals with a projection matrix Ps ⊥ to generate a first plurality of S-matrix columns and a plurality of intermediate signals, each of the plurality of intermediate signals having an associated one of the plurality of selected input signals;
a determination means configured for determining at least one of a sign and a relative amplitude for each of the plurality of selected input signals;
a second multiplication means configured for multiplying each of the plurality of intermediate signals with at least one of the sign and the relative amplitude of its associated one of the plurality of selected input signals to generate a plurality of intermediate columns;
a summing means configured for summing the plurality of intermediate columns to generate at least one additional S-matrix column; and
a storage means configured for storing the first plurality of S-matrix columns and the at least one additional S-matrix column to form the S matrix.
19. The apparatus recited in claim 18 wherein the plurality of input signals comprises up to 64 input signals.
20. The apparatus recited in claim 18, wherein the first multiplication means further comprises a selective-engagement means configured for determining whether or not to multiply each of the plurality of selected input signals with the projection matrix Ps ⊥.
21. The apparatus recited in claim 18, wherein the second multiplication means further comprises a selective-engagement means configured for determining whether to multiply each of the plurality of intermediate signals with at least one of the sign and the relative amplitude of its associated one of the plurality of selected input signals.
22. A method for generating an S matrix, comprising:
B. providing for multiplying each of the plurality of selected input signals with a projection matrix Ps ⊥ to generate at least one column of the S matrix;
C. providing for multiplying each of the plurality of selected input signals with a projection matrix Ps ⊥ to generate a plurality of intermediate signals, each of the plurality of intermediate signals having an associated one of the plurality of selected input signals;
D. providing for determining a relative amplitude for each of the plurality of selected input signals;
E. providing for multiplying each of the plurality of intermediate signals with the relative amplitude of its associated one of the plurality of selected input signals to generate a plurality of intermediate columns of the S matrix;
F. providing for summing the plurality of intermediate columns to generate at least one column of the S matrix; and
G. providing for storing the at least one column of the S matrix to form the S matrix.
23. The method recited in claim 22, wherein providing for multiplying each of the plurality of selected input signals with the projection matrix Ps ⊥ further comprises providing for determining whether to multiply each of the plurality of selected input signals with the projection matrix Ps ⊥.
24. An apparatus for generating an S matrix, comprising:
a selection means configured for determining which of a plurality of input signals to utilize for generating an S matrix to produce a plurality of selected input signals;
a first multiplication means configured for multiplying each of the plurality of selected input signals with a projection matrix Ps ⊥ to generate a plurality of columns of the S matrix and a plurality of intermediate signals, each of the plurality of intermediate signals having an associated one of the plurality of selected input signals;
a second multiplication means configured for multiplying each of the plurality of intermediate signals with the relative amplitude of its associated one of the plurality of selected input signals to generate a plurality of intermediate columns;
a summing means configured for summing the plurality of intermediate columns to generate at least one column of the S matrix; and
a storage means configured for storing the at least one column of the S matrix to form the S matrix.
25. The apparatus recited in claim 24, wherein the plurality of input signals comprises up to 64 input signals.
26. The apparatus recited in claim 24, wherein the first multiplication means further comprises a selective-engagement means configured for determining whether or not to multiply each of the plurality of selected input signals with the projection matrix Ps ⊥.
27. The apparatus recited in claim 24, wherein the second multiplication means further comprises a selective-engagement means configured for determining whether to multiply each of the plurality of intermediate signals with at least one of the sign and the relative amplitude of its associated one of the plurality of selected input signals.
28. A serial receiver for a wireless communication system, said communication system comprising:
a receiver means configured for receiving a signal y having a plurality of data parameters;
a plurality of fingers comprising at least one search finger and at least one tracking finger;
a control processor configured for receiving the signal y and the plurality of data parameters, said control processor configured for selecting which of the plurality data parameters to be sent to each of the plurality of fingers;
at least one correlator residing in said at least one tracking finger, said at least one correlator being configured to correlate said signaly with a reference signal sn;
a Coded Signal Processing Engine (CSPE) residing in said at least one tracking finger and configured for performing interference cancellation in the signal y, said CSPE comprising: an apparatus configured for generating a projection from the signal y, signal y comprising, a spread signal matrix si of the source of interest, signals of other interfering sources s1, s2, s3 . . . , sp; and noise n.
29. The serial receiver recited in claim 28, wherein the receiver means is further configured to divide the signaly into yi channel and a yQ channel.
30. The serial receiver recited in claim 29, wherein said at least one search finger comprises at least a first multiplier and a second multiplier, a summer for each of the yi and a yQ channels, and a comparator.
31. The serial receiver recited in claim 30, wherein in the yi channel said first multiplier is configured to multiply a pilot Walsh code with a short code to generate a first reference signal if the Walsh code is non-zero.
32. The serial receiver recited in claim 31, wherein said second multiplier is configured to multiply the first reference signal by an orthogonal projection matrix to generate a second reference signal with at least one interference signal removed.
33. The serial receiver recited in claim 32 further comprising a third multiplier configured to multiply the second reference signal with the signal yi to generate an intermediate signal.
34. The serial receiver recited in claim 33, wherein the intermediate signal is correlated by summing the product of yi and the second reference signal over a correlation length N in said summer to generate a first plurality of summation signals.
35. The serial receiver recited in claim 34 wherein in they yQ channel, said first multiplier is configured to multiply a pilot Walsh code with a short code to generate a first reference signal if the Walsh code is non-zero.
36. The serial receiver recited in claim 35, wherein said second multiplier is configured to multiply the first reference signal by a respective orthogonal projection matrix to generate a second reference signal having at least one interference signal removed.
37. The serial receiver recited in claim 36, wherein said third multiplier is configured to multiply the second reference signal with the signal yQ to generate a second intermediate signal.
38. The serial receiver recited in claim 37, wherein the second intermediate signal is correlated by summing the product of yQ and the second reference signal over a correlation length N in said summer to generate a second plurality of summation signals.
39. The serial receiver recited in claim 38, wherein said comparator is configured to process the first plurality of summation signals and the second plurality of summation signals to select a strongest summation signal.
40. A method for generating an S matrix, said S matrix having an in-phase S-matrix component and a quadrature-phase S-matrix component, said method comprising:
A. providing for determining which in-phase components of a plurality of input signals to utilize for generating the in-phase S matrix component for producing a plurality of selected in-phase input-signal components;
B. providing for multiplying each of the plurality of selected in-phase input-signal components with a projection matrix Ps i ⊥ to generate a plurality of in-phase S-matrix columns;
C. providing for storing the plurality of in-phase S-matrix columns to form the in-phase S matrix;
D. providing for determining which quadrature-phase components of the plurality of input signals to utilize for generating the quadrature-phase S matrix component for producing a plurality of selected quadrature-phase input-signal components;
E. providing for multiplying each of the plurality of selected quadrature-phase input-signal components with a projection matrix Ps Q ⊥ to generate a plurality of quadrature-phase S-matrix columns; and
F. providing for storing the plurality of quadrature-phase S matrix to form the quadrature-phase S matrix.
41. The method recited in claim 40 wherein providing for multiplying each of the plurality of selected in-phase input-signal components with a projection matrix Ps I ⊥ further comprises providing for determining whether to multiply the respective selected input signal with said projection matrix Ps I ⊥.
42. The method recited in claim 40 wherein providing for multiplying each of the plurality of selected in-phase input-signal components with a projection matrix Ps Q ⊥ further comprises providing for determining whether to multiply the respective selected input signal with said projection matrix Ps Q ⊥.
43. An apparatus configured to generate an S matrix, said S matrix having an in-phase S-matrix component and a quadrature-phase S-matrix component, said apparatus comprising:
a first selection means configured for determining which in-phase components of a plurality of input signals to utilize for generating the in-phase S-matrix component for producing a plurality of selected in-phase input-signal components;
a first multiplication means configured for multiplying each of the plurality of selected in-phase input signal components with a projection matrix Ps I ⊥ to generate a plurality of in-phase S-matrix columns;
a first storage means configured for storing the plurality of in-phase S-matrix columns to form the in-phase S-matrix component;
a second selection means configured for determining which quadrature-phase components of the plurality of input signals to utilize for generating the quadrature-phase S matrix component for producing a plurality of selected quadrature-phase input signal components;
a second multiplication means configured for multiplying each of the plurality of selected quadrature-phase input signal components with a projection matrix Ps Q ⊥ to generate a plurality of quadrature-phase S-matrix columns; and
a second storage means configured for storing the plurality of quadrature-phase S matrix columns to form the quadrature-phase S-matrix component.
44. The apparatus recited in claim 43 wherein the plurality of input signals comprises up to 64 input signals.
45. The apparatus recited in claim 43, wherein the first multiplication means further comprises a selective-engagement means configured for determining whether or not to multiply each of the plurality of selected input signals with the projection matrix Ps I ⊥.
46. The apparatus recited in claim 43, wherein the second multiplication means further comprises a selective-engagement means configured for determining whether or not to multiply each of the plurality of selected input signals with the projection matrix Ps Q ⊥.
47. A method for generating an S matrix, said S matrix having an in-phase S-matrix component and a quadrature-phase S-matrix component, said method comprising:
A. providing for determining which in-phase components of a plurality of input signals to utilize for generating the in-phase S-matrix component for producing a plurality of selected in-phase input-signal components;
B. providing for multiplying each of the plurality of selected in-phase input-signal components with a projection matrix Ps I ⊥ to generate a plurality of in-phase intermediate signals, each of the plurality of in-phase intermediate signals having an associated one of the plurality of selected in-phase input-signal components;
C. providing for utilizing relative amplitude information associated with each of the plurality of selected in-phase input-signal components to determine an in-phase input-signal component sign of each of the plurality of selected in-phase input-signal components;
D. providing for multiplying each of the plurality of in-phase intermediate signals with the in-phase input-signal component sign of its associated one of the plurality of selected in-phase input-signal components to generate a plurality of in-phase S-matrix columns;
E. providing for storing the plurality of in-phase S-matrix columns to form the in-phase S-matrix component;
F. providing for determining which quadrature-phase components of the plurality of input signals to utilize for generating the quadrature-phase S-matrix component for producing a plurality of selected quadrature-phase input-signal components;
G. providing for multiplying each of the plurality of selected quadrature-phase input-signal components with a projection matrix Ps Q ⊥ to generate a plurality of quadrature-phase S-matrix columns;
H. providing for utilizing relative amplitude information associated with each of the plurality of selected quadrature-phase input-signal components to determine a quadrature-phase input-signal component sign of each of the plurality of selected quadrature-phase input-signal components;
I. providing for multiplying each of the plurality of quadrature-phase intermediate signals with the quadrature-phase input-signal component sign of its associated one of the plurality of selected quadrature-phase input-signal components to generate a plurality of quadrature-phase S-matrix columns; and
J. providing for storing the plurality of quadrature-phase S matrix to form the quadrature-phase S matrix.
48. The method recited in claim 47 wherein providing for multiplying each of the plurality of selected in-phase input-signal components with a projection matrix Ps I ⊥ further comprises providing for determining whether to multiply the respective selected input signal with said projection matrix Ps I ⊥.
49. The method recited in claim 47 wherein providing for multiplying each of the plurality of selected in-phase input-signal components with a projection matrix Ps Q ⊥ further comprises providing for determining whether to multiply the respective selected input signal with said projection matrix Ps Q ⊥.
50. An apparatus configured to generate an S matrix, the S matrix having an in-phase S-matrix component and a quadrature-phase S-matrix component, said apparatus comprising:
a selection means configured for determining which in-phase components of a plurality of input signals to utilize for generating the in-phase S-matrix component for producing a plurality of selected input signals and a plurality of selected in-phase input-signal components;
a first multiplication means configured for multiplying each of the plurality of selected in-phase input-signal components with a projection matrix Ps I ⊥ to generate a plurality of in-phase intermediate signals, each of the plurality of in-phase intermediate signals having an associated one of the plurality of selected in-phase input-signal components;
a first sign-determination means configured for utilizing relative amplitude information associated with each of the plurality of selected in-phase input-signal components to determine an in-phase input-signal component sign of each of the plurality of selected in-phase input-signal components;
a second multiplication means configured for multiplying each of the plurality of in-phase intermediate signals with the in-phase input-signal component sign of its associated one of the plurality of selected in-phase input-signal components to generate a plurality of in-phase S-matrix columns;
a third multiplication means configured for multiplying each of a plurality of quadrature-phase components of the plurality of selected input signals with a projection matrix Ps Q ⊥ to generate a plurality of quadrature-phase S-matrix columns;
a second sign-determination means configured for utilizing relative amplitude information associated with each of the plurality of selected quadrature-phase input-signal components to determine a quadrature-phase input-signal component sign of each of the plurality of selected quadrature-phase input-signal components;
a fourth multiplication means configured for multiplying each of the plurality of quadrature-phase intermediate signals with the quadrature-phase input-signal component sign of its associated one of the plurality of selected quadrature-phase input-signal components to generate a plurality of quadrature-phase S-matrix columns; and
a second storage means configured for storing the plurality of quadrature-phase S matrix to form the quadrature-phase S-matrix component.
51. The apparatus recited in claim 50, wherein the plurality of input signals comprises up to 64 input signals.
52. The apparatus recited in claim 50, wherein the first multiplication means further comprises a selective-engagement means configured for determining whether or not to multiply each of the plurality of selected input signals with the projection matrix Ps I ⊥.
53. The apparatus recited in claim 50, wherein the third multiplication means further comprises a selective-engagement means configured for determining whether or not to multiply each of the plurality of selected input signals with the projection matrix Ps Q ⊥.
54. The apparatus recited in claim 50, wherein the second multiplication means further comprises a selective-engagement means configured for determining whether or not to multiply each of the plurality of in-phase intermediate signals with the in-phase input-signal component sign of its associated one of the plurality of selected in-phase input-signal components.
55. The apparatus recited in claim 50, wherein the fourth multiplication means further comprises a selective-engagement means configured for determining whether or not to multiply each of the plurality of quadrature-phase intermediate signals with the quadrature-phase input-signal component sign of its associated one of the plurality of selected quadrature-phase input-signal components.
56. A method for generating an S matrix, said S matrix having an in-phase S-matrix component and a quadrature-phase S-matrix component, said method comprising:
B. providing for multiplying each of the plurality of selected in-phase input-signal components with a projection matrix Ps i ⊥to generate a plurality of in-phase intermediate signals, each of the plurality of in-phase intermediate signals having an associated one of the plurality of selected in-phase input-signal components;
C. providing for determining a relative amplitude for each of the plurality of selected in-phase input-signal components;
D. providing for multiplying each of the plurality of in-phase intermediate signals with the relative amplitude of its associated one of the plurality of selected in-phase input-signal components to generate a plurality of columns of the in-phase S-matrix component;
E. providing for summing each of the plurality of columns of the in-phase S-matrix component to generate an in-phase composite column;
F. providing for storing said in-phase composite column to form the in-phase S-matrix component;
G. providing for determining which quadrature-phase components of the plurality of input signals to utilize for generating the quadrature-phase S-matrix component for producing a plurality of selected quadrature-phase input-signal components;
H. providing for multiplying each of the plurality of selected quadrature-phase input-signal components with a projection matrix Ps Q ⊥ to generate a quadrature-phase intermediate signal, each of the plurality of quadrature-phase intermediate signals having an associated one of the plurality of selected quadrature-phase input-signal components;
I. providing for determining a relative amplitude for each of the plurality of selected quadrature-phase input-signal components;
J. providing for multiplying each of the plurality of quadrature-phase intermediate signals with the relative amplitude of its associated one of the plurality of selected quadrature-phase input-signal components to generate a plurality of columns of the quadrature-phase S-matrix component;
K. providing for summing each of the plurality of columns of the quadrature-phase S-matrix component to generate a quadrature-phase composite column; and
L. providing for storing said quadrature-phase composite column to form the quadrature-phase S-matrix component.
57. An apparatus configured to generate an S matrix, said S matrix having an in-phase S-matrix component and a quadrature-phase S-matrix component, said apparatus comprising:
a first amplitude-determination means configured for determining a relative amplitude for each of the plurality of selected in-phase input-signal components;
a second multiplication means configured for multiplying each of the plurality of in-phase intermediate signals with the relative amplitude of its associated one of the plurality of selected in-phase input-signal components to generate a plurality of columns of the in-phase S-matrix component;
a first summing means configured for summing each of the plurality of columns of the in-phase S-matrix component to generate an in-phase composite column;
a first storage means configured for storing said in-phase composite column to form the in-phase S-matrix component;
a second selection means configured for determining which quadrature-phase components of the plurality of input signals to utilize for generating the quadrature-phase S-matrix component for producing a plurality of selected quadrature-phase input-signal components;
a third multiplication means configured for multiplying each of the plurality of selected quadrature-phase input-signal components with a projection matrix Ps Q ⊥ to generate a quadrature intermediate signal, each of the plurality of quadrature-phase intermediate signals having an associated one of the plurality of selected quadrature-phase input-signal components;
a second amplitude-determination means configured for determining a relative amplitude for each of the plurality of selected quadrature-phase input-signal components;
a fourth multiplication means configured for multiplying each of the plurality of quadrature-phase intermediate signals with the relative amplitude of its associated one of the plurality of selected quadrature-phase input-signal components to generate a plurality of columns of the quadrature-phase S-matrix component;
a second summing means configured for summing each of the plurality of columns of the quadrature-phase S-matrix component to generate a quadrature-phase composite column; and
a second storage means configured for storing said quadrature-phase composite column to form the quadrature-phase S-matrix component.
58. The apparatus recited in claim 57 wherein the plurality of input signals comprises up to 64 input signals.
59. The apparatus recited in claim 57, wherein the first multiplication means further comprises a selective-engagement means configured for determining whether or not to multiply each of the plurality of selected input signals with the projection matrix Ps I ⊥.
60. The apparatus recited in claim 57, wherein the third multiplication means further comprises a selective-engagement means configured for determining whether or not to multiply each of the plurality of selected input signals with the projection matrix Ps Q ⊥.
61. The apparatus recited in claim 57, wherein the second multiplication means further comprises a selective-engagement means configured for determining whether or not to multiply each of the plurality of in-phase intermediate signals with the relative amplitude of its associated one of the plurality of selected in-phase input-signal components.
62. The apparatus recited in claim 57, wherein the fourth multiplication means further comprises a selective-engagement means configured for determining whether or not to multiply each of the plurality of quadrature-phase intermediate signals with the relative amplitude of its associated one of the plurality of selected quadrature-phase input-signal components.
63. A method for generating an S matrix, said method comprising:
A. providing for selecting a plurality of input signals for generating the S matrix, the selection means producing a plurality of selected input signals;
B. providing for multiplying each of the plurality of selected input signals with a projection matrix Ps ⊥ to generate a plurality of intermediate signals, each of the plurality of intermediate signals being associated with one of the plurality of selected input signals;
D. providing for multiplying each of the plurality of intermediate signals with the relative amplitude of its associated one of the plurality of selected input signals to generate a plurality of columns of the S-matrix;
E. providing for summing the plurality of columns of the S-matrix to generate a composite column; and
F. providing for storing the first composite column to form the S matrix.
64. An apparatus for generating an S matrix, said apparatus comprising:
a selection means configured for selecting a plurality of input signals for generating the S matrix, the selection means producing a plurality of selected input signals;
a first multiplication means configured for multiplying each of the plurality of selected input signals with a projection matrix Ps ⊥ to generate a plurality of intermediate signals, each of the plurality of intermediate signals being associated with one of the plurality of selected input signals;
a determination means configured for determining a relative amplitude for each of the plurality of selected input signals;
a second multiplication means configured to multiply each of the plurality of intermediate signals with the relative amplitude of its associated one of the plurality of selected input signals to generate a plurality of columns of the S-matrix;
a summing means configured to sum the plurality of columns of the S-matrix to generate a composite column; and
a storage means configured for storing the first composite column to form the S matrix.
65. The apparatus recited in claim 64 wherein the plurality of input signals comprises up to 64 input signals.
66. The apparatus recited in claim 64, wherein the first multiplication means further comprises a selective-engagement means configured for determining whether to multiply each of the plurality of selected input signals with the projection matrix Ps ⊥.
67. The apparatus recited in claim 64, wherein said second means for multiplying further comprises a selective engagement means for determining whether to multiply each of the plurality of intermediate signals with the relative amplitude of its associated one of the plurality of selected input signals. Description
CROSS-REFERENCE TO RELATED APPLICATIONS This application is a divisional of U.S. patent application Ser. No. 10/247,836, filed Sep. 20, 2002, now U.S. Pat. No. 7,158,559 which claims priority to U.S. Provisional Patent Application No. 60/354,093, entitled �A Parallel CSPE Based Receiver for Communication Signal Processing,� filed Feb. 5, 2002; U.S. patent application Ser. No. 10/178,541, entitled �Method and Apparatus to Compute the Geolocation of a Communication Device Using Orthogonal Projections,� filed Jun. 25, 2002; U.S. Provisional Patent Application No. 60/348,106, entitled �Serial Receiver Design for a Coded Signal Processing Engine,� filed Jan. 14, 2002; U.S. Provisional Patent Application No. 60/333,143, entitled �Method and Apparatus to Compute the Geolocation of a Communication Device Using Orthogonal Projection Methods,� filed Nov. 27, 2001; U.S. Provisional Patent Application No. 60/331,480, entitled �Construction of an Interference Matrix for a Coded Signal Processing Engine,� filed Nov. 16, 2001; U.S. Provisional Patent Application No. 60/326,199, entitled �Interference Cancellation in a Signal,� filed Oct. 2, 2001; and U.S. Provisional Patent Application No. 60/325,215, entitled �An Apparatus for Implementing Projections in Signal Processing Applications,� filed Sep. 28, 2001; the entire disclosure and contents of these applications are hereby incorporated by reference. This application also incorporates by reference U.S. patent application Ser. No. 09/988,218, entitled �Interference Cancellation In a Signal,� filed Nov. 19, 2001, now U.S. Pat. No. 6,711,219; U.S. Provisional Patent Application No. 60/251,432, entitled �Architecture for Acquiring, Tracking and Demodulating Pseudorandom Coded Signals in the Presence of Interference,� filed Dec. 4, 2000; U.S. patent application Ser. No. 09/988,219, entitled �A Method and Apparatus for Implementing Projections in Signal Processing Applications,� filed Nov. 19, 2001, now U.S. Pat. No. 6,856,945; U.S. patent application Ser. No. 09/612,602, filed Jul. 7, 2000, now U.S. Pat. No. 6,430,216; and U.S. patent application Ser. No. 09/137,183, filed Aug. 20, 1998.
In spread spectrum systems, whether it is a wireless communication system, a Global Positioning System (GPS) or a radar system, each transmitter may be assigned a unique code and in many instances each transmission from a transmitter is assigned a unique code. The code is nothing more than a sequence (often pseudorandom) of bits. Examples of codes include Gold codes (used in GPS�see Kaplan, Elliot D., Editor, Understanding GPS: Principles and Applications, Artech House 1996), Barker codes (used in radar�see Stimson, G. W., �An Introduction to Airborne Radar�, SciTech Publishing Inc., 1998) and Walsh codes (used in communications systems, such as cdmaOne�See IS-95). These codes may be used to spread the signal so that the resulting signal occupies some specified range of frequencies in the electromagnetic spectrum or the codes may be superimposed on another signal, which may also be a coded signal.
Let H be a matrix containing the spread signal from source number 1 and let θ1 be the amplitude of the signal from this source. Let si be the spread signals for the remaining sources and let φi be the corresponding amplitudes. Suppose that the receiver is interested in source number 1. The signals from the other sources may be considered to be interference. The received signal is:
y=H 1 +s 2φ2 +s 3φ3 + . . . +s pφp +n (1)
y = H ⁢ ⁢ θ + S ⁢ ⁢ ϕ + n = [ HS ] ⁡ [ θ ϕ ] + n ( 2 ) where
φ=[φ2 . . . φp]: interference amplitude vector.
correlation function=(H T H)−1 H T y (3)
( H T ⁢ H ) - 1 ⁢ H T ⁢ y = ( H T ⁢ H ) - 1 ⁢ H T ⁡ ( H ⁢ ⁢ θ + S ⁢ ⁢ ϕ + n ) = ( H T ⁢ H ) - 1 ⁢ H T ⁢ H ⁢ ⁢ θ + ( H T ⁢ H ) - 1 ⁢ H T ⁢ S ⁢ ⁢ ϕ + ( H T ⁢ H ) - 1 ⁢ H T ⁢ n = θ + ( H T ⁢ H ) - 1 ⁢ H T ⁢ S ⁢ ⁢ ϕ + ( H T ⁢ H ) - 1 ⁢ H T ⁢ n ( 4 ) The middle term, (HTH)−1HTSφ, in the above equation is the source of the near-far problem. If the codes are orthogonal, then this term reduces to zero, which implies that the receiver has to detect θ in the presence of noise, i.e. (HTH)−1HTn) only. As the amplitudes of the other sources increase, the term (HTH)−1HTSφ contributes a significant amount to the correlation, which makes the detection of θ more difficult.
P s =S(S T S)−1 S T (5)
P s ⊥ =I−P s =I−S(S T S)−1 S T (6)
P s 195 (Sφ)=(I−S(S T S)−1 S T)Sφ=Sφ−S(S T S)−1 S T Sφ=Sφ−Sφ=0 (7)
P s ⊥ y=P s ⊥(Hθ+Sφ+n)=P s ⊥ Hθ+P s ⊥ Sφ+P s ⊥ n=P s ⊥ Hθ+P s ⊥ n (8)
Detection of the signal interest may then proceed with the processed measurement vector Ps ⊥ y with the interference signal(s) S removed.
SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a novel serial cancellation receiver architecture for the Coded Signal Processing Engine (CSPE).
In another embodiment, a serial receiver for a wireless communication system is provided, the communication system comprising: a means for receiving a signal y having data parameters; a control processor; the control processor for receiving the signal y and the data parameters; at least two fingers, the control processor for determining which data parameters are sent to respective fingers, wherein one finger is a search finger and at least one finger is a tracking finger; wherein the tracking finger comprises a correlator and a Coded Signal Processing Engine (CSPE), the CSPE for interference cancellation in the reception of the measured signal; wherein the CSPE comprises: an apparatus for generating a projection from a received signal (y), the signal comprising si, a signal of the source of interest; s1, s2, s3 . . . , sp signals of other interfering sources; and noise (n); the apparatus comprising: means for determining a basis vector U; means for storing elements of the basis vector U; means for determining yperp where: yperp=y−U(UTU)−1UTy; and wherein the search finger receives an input from the control processor, the input being selected from the group consisting of: y(k), a data stream in which k interference signals have been removed; and
∏ i , j ⁢ ⁢ P s i ( j ) ⊥ , a product of projection operators used to remove the k interference signals.
In another embodiment, a serial receiver for a wireless communication system is provided, the communication system comprising: a means for receiving a signal y having data parameters; a control processor; the control processor for receiving the signal y and the data parameters; at least two fingers, the control processor for determining which of the data parameters are sent to respective fingers, wherein one finger is a search finger and at least one finger is a tracking finger; wherein the tracking finger comprises a correlator and a Coded Signal Processing Engine (CSPE), the CSPE for interference cancellation in the reception of the measured signal; wherein the CSPE comprises: an apparatus for generating a projection from a received signal (y), the signal comprising si, a spread signal matrix of the source of interest; s1, s2, s3 . . . , sp, signals of other interfering sources; and noise (n); the apparatus comprising: (A) means for assigning s1 as a first basis vector u1; (B) means for determining σi, where ui Tui=σi; (C) means for storing ui; (D) means for computing inner products of the si+1 and the u1 through ui vectors; (E) means for multiplying the inner products with a respective scalar 1/σi and thereby creating a first intermediate product; (F) means for scaling each respective basis vector ui by multiplying each respective first intermediate product with each respective basis vector ui; (G) means for serially subtracting the intermediate product from si+1; (H) means for utilizing the result from step G and subtracting the next incoming value of
u i ⁢ 1 σ i ⁢ u i T ⁢ s i + 1 until all the values are processed; (I) means for obtaining the next basis vector ui+1 from step H; (J) means for comparing ui+1 to a predetermined value and if equal to or less than the value, going to step O; (K) means for storing ui+1; (L) means for determining an inner product of uT i+1ui+1; (M) means for determining the reciprocal of step K which is 1/σi+1; (N) means for storing 1/σi+1; (O) means for incrementing i; (P) means for conducting steps D through O until i=p, where p is the total number of the sources of interest; (Q) and means for determining yperp where: yperp=y−U(UTU)−1UTy; and wherein the search finger receives an input from the control processor, the input being selected from the group consisting of: y(k), a data stream in which k interference signals have been removed; and
In another embodiment, a serial receiver for a wireless communication system is provided, the communication system comprising: a means for receiving a signal y having data parameters; a control processor; the control processor for receiving the signal y and the data parameters; at least two fingers, the control processor for determining which of the data parameters are sent to respective fingers, wherein one finger is a search finger and at least one finger is a tracking finger; wherein the tracking finger comprises a correlator and a Coded Signal Processing Engine (CSPE), the CSPE for interference cancellation in the reception of the measured signal; wherein the CSPE comprises: an apparatus for generating a projection from a received signal (y), the signal comprising si, a signal of the source of interest; s1, s2, s3 . . . , sp, signals of other sources; and noise (n); the apparatus comprising: means for determining a basis vector U; means for storing elements of the basis vector U; means for determining yperp where: yperp=y−U(UTU)−1UTy; and wherein the search finger receives an input from the control processor, the input being selected from the group consisting of: y(k), a data stream in which k interference signals have been removed; and
∏ i , j ⁢ ⁢ P s i ( j ) ⊥ , a product of a projection operator used to remove the k interference signals.
In another embodiment, a modified Hadamard transform module is provided, the module comprising: an input signal y; means for splitting the input signal into a plurality of input channels; a plurality of relative amplitude generation channels, one associated with each of the input channels, wherein at least one of the relative amplitude generation channels comprises a respective Walsh code which is multiplied by a projection matrix Ps 195 and the signal y to generate a respective intermediate channel signal; and a summer for summing the respective intermediate channel signal over a Walsh symbol to generate the respective channel's amplitude.
A. Receiving a plurality of input signals W1 through Wn, where n represents the number of input signals; B. Determining which input signals will be utilized in the generation of matrix S; C. Multiplying each selected input signal with a projection matrix Ps ⊥ to generate a column of matrix S; and D. Storing each respective column to form matrix S. In another embodiment, an apparatus for generating an S matrix is provided, the apparatus comprising: a means for receiving a plurality of input signals W1 through Wn, where n represents the number of input signals; a means for determining which input signals will be utilized in the generation of matrix S; a means for multiplying each selected input signal with a projection matrix Ps ⊥ to generate a column of matrix S; and means for storing each respective column to form matrix S.
A. Receiving a plurality of input signals W1 through Wn, where n represents the number of input signals; B. Determining which input signals will be utilized in the generation of matrix S; C. Multiplying each selected input signal with a projection matrix Ps ⊥ to generate an intermediate signal; D. Utilizing relative amplitude information associated with the selected input signals to determine the sign of the selected input signal; E. Multiplying the intermediate signal with its associated sign to generate a column of matrix S; and F. Storing each respective column to form matrix S. In another embodiment, an apparatus for generating an S matrix is provided, the apparatus comprising: a means for receiving a plurality of input signals W1 through Wn, where n represents the number of input signals; a means for determining which input signals will be utilized in the generation of matrix S; a first means for multiplying each selected input signal with a projection matrix Ps ⊥ to generate an intermediate signal; a means for utilizing relative amplitude information associated with the input signals to determine the sign of the input signal; a second means for multiplying the intermediate signal with its associated sign to generate a column of matrix S; and means for storing each respective column to form matrix S.
A. Receiving a plurality of input signals W1 through Wn, where n represents the number of input signals; B. Determining which input signals will be utilized in the generation of matrix S; C. Multiplying each selected input signal with a projection matrix Ps ⊥ to generate an intermediate signal; D. Determining relative amplitude associated with the selected input signals; E. Multiplying the intermediate signal with its associated relative amplitude to generate a column of matrix S; and F. Storing each respective column to form matrix S. In another embodiment, an apparatus for generating an S matrix is provided, the apparatus comprising: a means for receiving a plurality of input signals W1 through Wn, where n represents the number of input signals; a means for determining which input signals will be utilized in the generation of matrix S; a first means for multiplying each selected input signal with a projection matrix Ps ⊥ to generate an intermediate signal; a means for determining relative amplitude associated with the respective input signal; a second means for multiplying the intermediate signal with its associated relative amplitude to generate a column of matrix S; and means for storing each respective column to form matrix S.
A. Receiving a plurality of input signals W1 through Wn, where n represents the number of input signals; B. Determining which input signals will be utilized in the generation of matrix S; C. Multiplying each selected input signal with a projection matrix Ps ⊥ to generate an intermediate signal; D. Determining relative amplitude associated with the selected input signals; E. Multiplying the intermediate signal with its associated relative amplitude to generate an intermediate column; F. Summing all intermediate columns to generate a column of matrix S; and G. Storing each respective column of matrix S to form matrix S. In another embodiment, an apparatus for generating an S matrix is provided, the apparatus comprising: a means for receiving a plurality of input signals W1 through Wn, where n represents the number of input signals; a means for determining which input signals will be utilized in the generation of matrix S; a first means for multiplying each selected input signal with a projection matrix Ps ⊥ to generate a column of matrix S and an intermediate signal; means for determining relative amplitude associated with the selected input signals; second means for multiplying the intermediate signal with its associated relative amplitude to generate an intermediate column; means for summing all intermediate columns to generate a column of matrix S; and means for storing each respective column of matrix S to form matrix S.
A. Receiving a plurality of input signals W1 through Wn, where n represents the number of input signals and where each input signal W has an in-phase component (WI) and a quadrature component (WQ); B. Determining which in-phase components of the input signals will be utilized in the generation of matrix SI; C. Multiplying each in-phase component of the selected input signal with a projection matrix Ps I ⊥ to generate a column of matrix SI; D. Storing each respective column to form matrix SI; E. Determining which quadrature components of the input signals will be utilized in the generation of matrix SQ; F. Multiplying each quadrature component of the selected input signal with a projection matrix Ps Q ⊥ to generate a column of matrix SQ; and G. Storing each respective column to form matrix SQ. In another embodiment, an apparatus for generating an S matrix is provided, the S matrix having an in-phase and a quadrature component, the apparatus comprising: a means for receiving a plurality of input signals W1 through Wn, where n represents the number of input signals and where each input signal W has an in-phase component (WI) and a quadrature component (WQ); a means for determining which in-phase components of the input signals will be utilized in the generation of matrix SI; a first means for multiplying each in-phase component of the selected input signal with a projection matrix Ps I ⊥ to generate a column of matrix SI; means for storing each respective column to form matrix SI; a means for determining which quadrature components of the input signals will be utilized in the generation of matrix SQ; a second means for multiplying each quadrature component of the selected input signal with a projection matrix Ps Q ⊥ to generate a column of matrix SQ; and means for storing each respective column to form matrix SQ.
A. Receiving a plurality of input signals W1 through Wn, where n represents the number of input signals and where each input signal W has an in-phase component (WI) and a quadrature component (WQ); B. Determining which in-phase components of the input signals will be utilized in the generation of matrix SI; C. Multiplying each in-phase component of the selected input signal with a projection matrix Ps I ⊥ to generate an in-phase intermediate signal; D. Utilizing relative amplitude information associated with the in-phase component of the selected input signals to determine the sign of the selected in-phase component of the input signal; E. Multiplying the in-phase intermediate signal with its associated sign to generate a column of matrix SI; F. Storing each respective column to form matrix SI; G. Determining which quadrature components of the input signals will be utilized in the generation of matrix SQ; H. Multiplying each quadrature component of the selected input signal with a projection matrix Ps Q ⊥ to generate a quadrature intermediate signal; I. Utilizing relative amplitude information associated with the quadrature component of the selected input signals to determine the sign of the selected quadrature component of the input signal; J. Multiplying the quadrature intermediate signal with its associated sign to generate a column of matrix SQ; and K. Storing each respective column to form matrix SQ. In another embodiment, an apparatus for generating an S matrix is provided, the S matrix having an in-phase and a quadrature component, the apparatus comprising: means for receiving a plurality of input signals W1 through Wn, where n represents the number of input signals and where each input signal W has an in-phase component (Wi) and a quadrature component (WQ); a means for determining which in-phase components of the input signals will be utilized in the generation of matrix SI and SQ; a first means for multiplying each in-phase component of the selected input signal with a projection matrix Ps I ⊥ to generate an in-phase intermediate signal; a means for utilizing relative amplitude information associated with the in-phase component of the input signals to determine the sign of the in-phase component of the input signal; a second means for multiplying the in-phase intermediate signal with its associated sign to generate a column of matrix SI; means for storing each respective column to form matrix SI; a third means for multiplying each quadrature component of the selected input signal with a projection matrix Ps Q ⊥ to generate a quadrature intermediate signal; a means for utilizing relative amplitude information associated with the quadrature component of the input signals to determine the sign of the quadrature component of the input signal; a fourth means for multiplying the quadrature intermediate signal with its associated sign to generate a column of matrix SQ; and means for storing each respective column to form matrix SQ.
A. Receiving a plurality of input signals W1 through Wn, where n represents the number of input signals and where each input signal W has an in-phase component (WI) and a quadrature component (WQ); B. Determining which input signals will be utilized in the generation of matrix SI; C. Multiplying each in-phase component of the selected input signal with a projection matrix Ps I ⊥ to generate an in-phase intermediate signal; D. Determining relative amplitude associated with the in-phase component of the selected input signals; E. Multiplying the in-phase intermediate signal with its associated relative amplitude to generate a column of matrix SI; F. Summing each column of matrix SI to generate a composite column; G. Storing the composite column to form matrix SI; H. Determining which input signals will be utilized in the generation of matrix SQ; I. Multiplying each quadrature component of the selected input signal with a projection matrix Ps Q ⊥ to generate a quadrature intermediate signal;
J. Determining relative amplitude associated with the quadrature component of the selected input signals; K. Multiplying the quadrature intermediate signal with its associated relative amplitude to generate a column of matrix SQ; L. Summing each column of matrix SQ to generate a composite column; and M. Storing the composite column to form matrix SQ. In another embodiment, an apparatus for generating an S matrix is provided, the S matrix having an in-phase and a quadrature component, the apparatus comprising: a means for receiving a plurality of input signals W1 through Wn, where n represents the number of input signals and where each input signal W has an in-phase component (Wi) and a quadrature component (WQ); a means for determining which input signals will be utilized in the generation of matrix SI and SQ; a first means for multiplying each in-phase component of the selected input signal with a projection matrix Ps I ⊥ to generate an in-phase intermediate signal; a means for determining relative amplitude associated with the in-phase component of the respective input signal; a second means for multiplying the in-phase intermediate signal with its associated relative amplitude to generate a column of matrix SI; first means for summing each column of matrix SI to generate a first composite column; first means for storing the first composite column to form matrix SI; a third means for multiplying each quadrature component of the selected input signal with a projection matrix Ps Q ⊥ to generate a quadrature intermediate signal; a means for determining relative amplitude associated with the quadrature component of the respective input signal; a fourth means for multiplying the quadrature intermediate signal with its associated relative amplitude to generate a column of matrix SQ; means for summing each column of matrix SQ to generate a second composite column; and means for storing the second composite column to form matrix SQ.
A. Receiving a plurality of input signals W1 through Wn, where n represents the number of input signals; B. Determining which input signals will be utilized in the generation of matrix S; C. Multiplying each of the selected input signals with a projection matrix Ps ⊥ to generate an intermediate signal; D. Determining relative amplitude associated with the component of the selected input signals; E. Multiplying the intermediate signal with its associated relative amplitude to generate a column of matrix S; F. Summing each column of matrix S to generate a composite column; and G. Storing the composite column to form matrix S. Other objects and features of the present invention will be apparent from the following detailed description of the preferred embodiment.
FIG. 9 is a block diagram depicting a module for the generation of an interference matrix S, using �no information� of sign or relative amplitude, which may be utilized in conjunction with the teachings of the present invention in a cdmaOne system and/or cdma2000 system;
FIG. 10 is a block diagram depicting a module for the generation of an interference matrix S, using �sign information�, that may be utilized in conjunction with the teachings of the present invention in a cdmaOne system and/or cdma2000 system;
FIG. 11 is a block diagram depicting a module for the generation of an interference matrix S, using �relative amplitude (composite)� information, which may be utilized in conjunction with the teachings of the present invention in a cdmaOne system and/or cdma2000 system;
FIGS. 16A and 16B are block diagrams depicting in phase and quadrature modules for the generation of a �no information� interference matrix S that may be utilized in conjunction with the teachings of the present invention in a cdma2000 system;
FIGS. 17A and 17B are block diagrams depicting in phase and quadrature modules for the generation of a �sign information� interference matrix S that may be utilized in conjunction with the teachings of the present invention in a cdma2000 system; and
FIGS. 18A and 18B are block diagrams depicting in phase and quadrature modules for the generation of �relative amplitude (composite)� interference matrix S that may be utilized in conjunction with the teachings of the present invention in a cdma2000 system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT It is advantageous to define several terms before describing the invention. It should be appreciated that the following definitions are used throughout this application. Where the definition of terms departs from the commonly used meaning of the term, applicant intends to utilize the definitions provided below, unless specifically indicated.
DEFINITIONS For the purposes of the present invention, the term �cross-channel interference� refers to the type of interference that results from one source's signals bleeding into the acquisition and tracking channels of another source.
For the purposes of the present invention, the term �co-channel interference� refers to the type of interference that occurs when one or more signals, e.g., a line-of-sight signal; interferes with the ability to acquire a second, third or other multipath signal from the same source.
For the purposes of the present invention, the term �finger� refers to either an LOS or multipath copy of a signal from any source. It may consist of multiple channels. For example, an IS-95 multipath finger may consist of the pilot, paging, synchronization and a number of traffic channels.
For the purposes of the present invention, the term �multipath finger� refers specifically to either an LOS or multipath signal from a single source. It may consist of multiple channels. For example, an IS-95 multipath finger may consist of the pilot, paging, synchronization and a number of traffic channels.
For the purposes of the present invention, the term �processing finger� refers to a signal-processing element in a receiver that tracks a single multipath finger and processes a single channel contained in a multipath finger. For example, in an IS-95 mobile receiver, each processing finger tracks a single multipath finger of a channel.
For the purposes of the present invention, the term �base station� refers to a transmitter and/or receiver that is capable of communicating with multiple mobile units in a wireless environment.
For the purposes of the present invention, the term �baseline receiver� refers to a conventional CDMA receiver against which a receiver of the present invention may be compared.
For the purposes of the present invention, the term �baseline finger processor� refers to a processing finger in a baseline receiver that tracks a finger.
For the purposes of the present invention, the term �bit� refers to the conventional meaning of �bit,� i.e., a fundamental unit of information having one of two possible values; a binary 1 or 0.
For the purposes of the present invention, the term �chip� refers to a non-information bearing unit that is smaller than a bit, the fundamental information bearing unit. Use of spreading codes produce fixed length sequences of chips that constitute bit(s).
For the purposes of the present invention the term �code� refers to a specified sequence of numbers that is applied to a message and is known by the intended recipient of the message.
For the purposes of the present invention, the term �code offset� refers to a location within a code. For example, base stations in certain wireless environments distinguish between each other by their location within a code, often a pseudorandom sequence.
For the purposes of the present invention, the term �correlation� refers to the inner product between two signals, typically scaled by the length of the signals or by another normalization factor. Correlation provides a measure of how alike two signals are.
For the purposes of the present invention, the term �digital� refers to the conventional meaning of the term digital, i.e., relating to a measurable quantity that is discrete in nature.
For the purposes of the present invention, the term �Doppler� refers to the conventional meaning of the term Doppler, i.e., a shift in frequency that occurs due to movement of a receiver, transmitter and/or background.
For the purposes of the present invention, the term �Global Positioning System (GPS)� refers to the conventional meaning of this term, i.e., a satellite-based system for position location.
For the purposes of the present invention, the term �quadrature� refers to the component of a signal that is 90� out of phase with a particular signal, such as a reference signal.
For the purposes of the present invention, the term �interference� refers to the conventional meaning of the term interference, i.e., a signal that is not of interest but that interferes with the ability to detect the signal of interest. Generally, interference is structured noise that is created by other processes that are attempting to do the same thing as the signal of interest, e.g., other base stations communicating with mobiles, or multipath versions of the signal of interest.
For the purposes of the present invention, the term �linear combination� refers to the combining of multiple signals or mathematical quantities in an additive way with nonzero scaling of the individual signals.
For the purposes of the present invention, the term �noise� refers to the conventional meaning of noise with respect to the transmission and reception of signals, i.e., a random disturbance that limits the ability to detect a signal of interest. Specifically, it refers to processes that are attempting to do something different than the signal of interest. Additive noise adds linearly with the power of the signal of interest. Examples of noise in cellular systems may include automobile ignitions, power lines and microwave communication links.
For the purpose of the present invention, the term �matrix inverse� refers to the inverse of a square matrix S, denoted by S−1, that is defined as that matrix which when multiplied by the original matrix equals the identity matrix, I, i.e., a matrix which is all zero save for a diagonal of all ones.
For the purposes of the present invention, the term �mobile� refers to a mobile phone which functions as a transmitter or receiver and communicates with base stations.
For the purposes of the present invention, the term �modulation� refers to imparting information on another signal, such as a sinusoidal signal or a pseudorandom coded signal. Typically, this is accomplished by manipulating signal parameters, such as phase, amplitude, frequency or some combination of these quantities.
For the purposes of the present invention, the term �multipath� refers to copies of a signal that travel different paths to the receiver.
For the purposes of the present invention, the term �pseudorandom number (PN)� sequences refer to sequences that are often used in spread spectrum applications as codes to distinguish between users while spreading the signal in the frequency domain.
For the purposes of the present invention, the term �projection�, with respect to any two vectors x and y, refers to the projection of the vector x onto y in the direction of a y with a length equal to that of the component of x, which lies in the y direction.
For the purposes of the present invention, the term �quasi-orthogonal functions (QOF)� refers to a set of orthogonal functions used in cdma2000. QOFs are orthogonal within a set, but between different QOF sets and Walsh codes there exists non-zero correlation between at least one pair of codes from these different sets.
For the purposes of the present invention, the term �signal to noise ratio (SNR)� refers to the conventional meaning of signal to noise ratio, i.e., the ratio of the signal to noise (and interference).
For the purposes of the present invention, the term �spreading code� refers to pseudorandom number sequences that are used to increase the width of the signal in frequency space in spread spectrum systems. Examples of spreading codes include: Gold, Barker, Walsh codes, etc.
For the purposes of the present invention, the term �symbol� refers to the fundamental information-bearing unit transmitted over a channel in a modulation scheme. A symbol may be composed of one or more bits that may be recovered through demodulation
DESCRIPTION The serial cancellation CSPE receiver incorporates the coded signal-processing engine (CSPE) into a spread spectrum receiver architecture in which interference cancellation is performed in a serial manner. Specifically, interference cancellation operations of single fingers, e.g., single LOS or multipath from a transmission source, on the measured data are performed in a serial, or cascading, manner, typically from highest to lowest power signals. Each processing finger may operate on the measured data y or on processed data in which one or more interference signals have been cancelled. One benefit of the serial approach is that a serial receiver processing-finger may acquire, track and demodulate a signal that is buried beneath the interference floor. A master control module controls data flow and control signals for all processing fingers. Depending on the power of the signals acquired, the CSPE may or may not cancel the interference of the previous signal(s).
Control Control block 206 controls data flow for all processing fingers 210, 212, 214 in receiver 200, i.e., it determines which data stream, time offsets, projection operators and other parameters are sent to each processing finger 210, 212, 214. Moreover, it maintains a master time or an equivalent method of representing time of arrival that is used by all the processing fingers for the determination of code offsets in time. Controller 206 may be modified as desired to achieve particular network requirements. Note that it is to be understood that various changes and modifications may be made to controller 206 without departing from the teachings of the present invention. Such changes and modifications are to be understood as included within the scope of the present invention. For example, due to memory and other computational reasons it may be necessary to pass the interference matrix S to a module rather than the projection matrix PS 195.
In a preferred embodiment, the inputs for controller 206 are illustrated as items 202 and 204 and may include, but are not limited to: y(j)�data stream containing the transmitted signals where the j index specifies the number of interference signals that have been removed; tk�time offset for the signal, where k is the signal index; Ps n (k) ⊥�projection operator, where the n index denotes the signal number while the k index specifies the number of interference signals that have been removed; P�estimate of the power of the tracked signals to determine which signals should be cancelled and in which order the signals should be cancelled; and Info�an optional parameter that may either specify relative signal amplitude of the signals or polarity of the bits transmitted. This information is specifically used for cancellation purposes. The minimum input parameters for cancellation purposes include: y(j), tk, and Ps n (k) ⊥.
The outputs for controller 206 are illustrated as data elements 208, 210, 212, 214, and 216. Each of these data elements may contain: y(k)�a data stream in which k interference signals have been removed;
∏ i , j ⁢ ⁢ P s i ( j ) ⊥ - a product of the projection operators that is used to remove the k interference signals; and/or tk�time offset for the kth interference signal.
Searcher Finger Searcher finger block 220 acquires a signal in the received data 208. Inputs for searcher finger block 220, include, but are not limited to: y(j)�a data stream in which j interference signals have been removed; and
∏ i , j ⁢ ⁢ P s i ( j ) ⊥ - a product of the projection operators, which is used to remove the k interference signals. Searcher finger block 220 provides time offset and relative power information to finger processor 260. The time offset is a coarse approximation, the accuracy of which is further refined in the tracking loop or code offset estimation of finger processor 260. Searcher finger block 220 may operate on either the unprocessed segment of data or on a processed segment of data, which has been operated on by a projection operator in a processing finger's CSPE block in order to remove an interference signal(s).
Depending on the constraints of the system, the searcher algorithm may take many forms. A standard CDMA searcher continually searches the unprocessed segment y 202 for new signals to be assigned to processing fingers 210, 212, 214. Embodiments of the present invention have the capability to search within unprocessed data and the processed data, e.g., y(1), y(2), . . . , y(n−1). For example, the searcher algorithm may focus its processing time on the y 202 with the greatest number of signals removed to facilitate the acquisition of signals buried by the interference, it could search each y alternatively for a short period of time or have additional searchers or correlators search y(1), y(2), . . . , y(n−1). The former has difficulties when the relative powers of the signals are changing and fingers are being reassigned because of the dependencies of cancellation ordering in the serial cancellation process. The latter may unnecessarily process y's with few or no signals cancelled, thereby decreasing the probability of acquiring additional signals since they may be buried beneath the interference floor of stronger signals. The addition of new searchers or correlators may be costly to implement. The complexity of the searcher algorithm is dependent on the parameters of receiver architecture.
The use of any prior art searcher algorithm is considered within the scope of the present invention. As may be seen, the outputs from searcher finger block 220 are preferably, tm�time offset for the (m)th signal acquired by the searcher; and an estimate of signal power that is used to determine the order of the serial cancellation and to determine whether signal cancellation is required for the acquisition of particular signals. The output is illustrated by element 222. Outputs 222 may be utilized to facilitate the acquisition of signals buried by the interference or may search each y(j) alternatively for a short period of time, for simplicity, and may be provided to controller 206 as input 204 for these purposes.
Baseline Finger Processor Baseline finger processor 230 tracks a signal in the received data y(k) in 212. It provides time offset information tk+1 and an estimate of the tracked signal (reference signal) 232 to subsequent blocks in the processing finger for correlator 240 and for the construction of interference matrices 250. The inputs for baseline finger processor 230 are illustrated by element 212 and include: y(k)�a data stream in which k interference signals have been removed; and
∏ i , j ⁢ ⁢ P s i ( j ) ⊥ - a product of the projection operators which is used to remove the k interference signals.
∏ i , j ⁢ ⁢ P s i ( j ) ⊥ ⁢ s n - a product of the projection operators, used to remove the k interference signals, and a reference signal of the signal tracked in the baseline receiver where n specifies the signal index; and tk+1�time offset for the (k+1)th signal tracked in the baseline receiver. These outputs are represented by element 232. As may be seen, output 232 is provided to both correlator 240 and CSPE 250.
Correlator block 240 (shown in FIG. 2) calculates a power estimate P in 244 that is used by control block 206 to order the signals for serial cancellation. Namely, it determines whether a cancellation is necessary in each processing finger and in which order. Additionally, the parameter Info is provided that supplies either information on bits transmitted, relative power information or no information to control block 206 depending on the receiver architecture. Information on bits transmitted or relative power is necessary for certain cancellation methods where there is bit boundary misalignment and where cancellation is performed on segments longer than one Walsh symbol as disclosed in U.S. Provisional Patent Application No. 60/331,480, entitled �Construction of an Interference Matrix for a Coded Signal Processing Engine,� the entire contents and disclosure of which is hereby incorporated by reference herein.
∏ i , j ⁢ ⁢ P s i ( j ) ⊥ ⁢ s n - a product of the projection operators that remove the k interference signals and an estimate of the signal tracked in the baseline receiver where n specifies the signal index; and tk+1�time offset for the (k+1)th signal tracked in the baseline receiver. The outputs of correlator 240 include: Info�either bits transmitted or relative signal amplitude information, if required by the cancellation method; and Power�estimate of signal power that is used to determine the order of the serial cancellation and to determine whether signal cancellation is required for the acquisition and/or tracking of particular signals.
To track signal s1 from the original data y, the data is correlated with a reference signal for s1 in block 240. However, to track a signal sn after k interference signals have been removed, data is correlated with a reference signal sn (k), which is produced after multiplying the original sn by the k corresponding projection operators, or by the reference signal sn (k−1). The flexibility in being able to use two different reference signals, i.e. either sn (k) or sn (k−1), for the correlation operation with y(i), where i>0, is due to the idempotent nature of projection matrices, i.e., (PS ⊥)T(PS ⊥)=PS ⊥.
s 2 (1) T y (1)=(P S 1 ⊥ s 2)T(P S 1 ⊥ y)=s 2 T P S 1 ⊥ T P S 1 ⊥ y=s 2 T P S 1 ⊥ y=s 2 T(P S 1 ⊥ y)=s 2 T y (1) (9)
s m ( n ) ⁢ T ⁢ y ( n ) = ⁢ = ( P s n � P s n - 1 � � ⁢ � P s i ⁢ s m ) T ⁢ ( P s n � P s n - 1 � � ⁢ � P s 1 ⁢ y ) ⁢ = s m T ⁢ P s 1 T � � ⁢ � P s n - 1 T � P s n T ⁢ P s n � P s n - 1 � � ⁢ � P s 1 ⁢ y ⁢ = s m T ⁢ P s 1 T � � ⁢ � P s n - 1 T � P s n � P s n - 1 � � ⁢ � P s 1 ⁢ y ⁢ = ( P s n - 1 � P s n - 2 � � ⁢ � P s 1 ⁢ s m ) T ⁢ ( P s n � P s n - 1 � � ⁢ � P s 1 ⁢ y ) ⁢ = s m ( n - 1 ) T ⁢ y ( n ) ( 10 ) Both the correlation sm (n) T y(n) and the correlation sm (n−1) T y(n) are mathematically equivalent, though the latter is computationally more efficient since it requires the application of one fewer projection matrix.
P s ⊥ =I−S(S T S)−1 S T (11)
P s ⊥ y=y−S(S T S)−1 S T y (12)
∏ i , j ⁢ ⁢ P s i ( j ) ⊥ ⁢ s n - a product of the projection operators, used to remove the k interference signals, and the signal tracked in the baseline receiver where the n specifies the signal index; tk+1�time offset for the (k+1)th signal tracked in the baseline receiver; and, if required, Info�either bits transmitted or relative signal amplitude information. The outputs for CSPE include: sn (k)�an estimate (reference signal) of the signal currently tracked in the processing finger; y(k)�a processed data stream in which k interference signals have been removed; y(k+1)�a processed data stream in which k+1 interference signals have been removed including the signal currently being tracked; tk+1�time delay for the (k+1)th signal tracked in the baseline receiver; and Ps n (k) ⊥�projection operator for the removal of sn (k).
For a detailed description of the CSPE, the reader is referred to U.S. Provisional Patent Application No. 60/331,480, entitled �Construction of an Interference Matrix for a Coded Signal Processing Engine,� filed Nov. 16, 2001; U.S. patent application Ser. No. 09/988,218, entitled �Interference Cancellation In a Signal,� filed Nov. 19, 2001; U.S. patent application Ser. No. 09/988,219, entitled �A Method and Apparatus for Implementing Projections in Signal Processing Applications,� filed Nov. 19, 2001; U.S. Provisional Patent Application No. 60/326,199, entitled �Interference Cancellation in a Signal,� filed Oct. 2, 2001; U.S. Provisional Patent Application No. 60/325,215, entitled �An Apparatus for Implementing Projections in Signal Processing Applications,� filed Sep. 28, 2001; U.S. Provisional Patent Application No. 60/251,432, entitled �Architecture for Acquiring, Tracking and Demodulating Pseudorandom Coded Signals in the Presence of Interference,� filed Dec. 4, 2000; U.S. patent application Ser. No. 09/612,602, filed Jul. 7, 2000; and to U.S. patent application Ser. No. 09/137,183, filed Aug. 20, 1998. The entire disclosures and contents of these applications are hereby incorporated by reference.
(Ps 1 {tilde over ( )} ⊥s2)T(Ps 1 {tilde over ( )} ⊥y) (13)
where the �{tilde over ( )}� denotes that the projection operator is aligned to the symbol boundaries of s2 rather than with s1. As a result, Ps 1 {tilde over ( )} ⊥ is mathematically not a true projection operator. Instead, it is composed of portions of two adjacent Ps 1 ⊥ operators that comprise the upper and lower portions of the Ps 1 {tilde over ( )} ⊥ matrix. Since, in general, the resulting matrix is not a true projection matrix, it is not guaranteed to be idempotent. Therefore, in the case of demodulation with misalignment between what is being cancelled and what is being demodulated, the following statement is, in general, not true:
s m (n) T y (n) =s m (n−1) T y (n) (14)
s m (n) T y (n) =s m (n−1) T y (n) (15)
Processing the Data Suppose that the received data is composed of m signals ordered in terms of power from highest to lowest with additive white Gaussian noise (AWGN). The data y may be written as
y=s 1 1 +s 2 2 +s 3 3 + . . . +s m−1 m−1 +s m m +n (16)
where s1 denotes the ith signal, θ1 denotes the ith amplitude and n represents the noise term. Note a slight departure from previous convention in the prior art section where H, s, θ and φ were used. This change eliminates the need for H to be re-defined after each serial cancellation operation.
First Processing Finger Control block 206 sends the raw received signal data y, but no Ps ⊥ information or time t information to the finger processing block 260 and y to CSPE block 250. Baseline block 230 calculates an estimate of the parameters corresponding to the signal of interest by correlating with a generated reference signal s1 and the signal, offset delay t1 and potentially the phase and doppler frequency to CSPE block 250 and correlator block 240. CSPE block 250 generates the projection operator Ps 1 ⊥ and operates on the data y to produce the processed data y(1) with the first signal removed.
P s 1 ⊥ =I−s 1(s 1 T s 1)−1 s 1 T (17) y (1) =P s 1 ⊥ y (18) y (1) =P s 1 ⊥ s 1θ1 +P s 1 ⊥ s 2θ2 +P s 1 ⊥ s 3θ3 + . . . +P s 1 ⊥ s m-1θm-1 +P s 1 ⊥ s mθm +P s 1 ⊥ n (19) y (1) =P s 1 ⊥ s 2θ2 +P s 1 ⊥ s 3θ3 + . . . +P s 1 ⊥ s m-1θm-1 +P s 1 ⊥ s mθm +P s 1 ⊥ n (20)
For simplicity, any nonzero multiplicative operation on the noise term n will produce a product n, i.e., Xn=n. Moreover, si (1) is defined as s1 (1)=Ps 1 ⊥si.
y (1) =s 2 (1)θ2 +s 3 (1)θ3 + . . . +s m−1 (1)θm−1 +s m (1)θm +n (21)
Second Processing Finger According to an embodiment of the present invention, without loss of generality, the control block sends the processed data y(1), Ps 1 ⊥ and the time offset information t1 to the baseline finger processing block and y(1) to the CSPE block to effectively find a second signal with the strongest signal cancelled. The baseline finger processing block calculates an estimate of the next strongest signal by correlating with either the generated reference signal s2 (1)=Ps 1 ⊥s2 or s2 and sends the signal and offset delay t2 to the CSPE and correlator blocks. The CSPE block generates the projection operator Ps 2 (1) ⊥ and operates on the data y(1) to produce the processed data y(2) that has the second signal removed.
P s 2 (1) ⊥ =I−s 2 (1)(s 2 (1) T s 2 (1))−1 s 2 (1) T (22) y (2) =P s 2 (1) ⊥ y (1) =P s 2 (1) ⊥ P s 1 ⊥ y (23) y (2) =P s 2 (1) ⊥ s 2 (1)θ2 +P s 2 (1) ⊥ s 3 (1)θ3 +P s 2 (1) ⊥ s 4 (1)θ4 + . . . +P s 2 (1) ⊥ s m−1 (1)θm−1 +P s 2 (1) ⊥ s m (1)θm +P s 2 (1) ⊥ n (24) y (2) =s 3 (2)θ3 +s 4 (2)θ4 + . . . +s m−1 (2)θm−1 +s m (2)θm +n (25)
Third Processing Finger According to an embodiment of the present invention, without loss of generality, the second signal does not need to be removed and the control block sends the processed data y(1), Ps 1 ⊥ and the time delay information t2 to the baseline receiver block and y(1) to the CSPE block to effectively find the third strongest signal with the signal in processing finger 1 removed. The baseline finger processing block calculates an estimate of the next strongest signal by correlating with a generated reference signal s3 (1)=Ps 1 ⊥ s3 or s3 and sends the reference signal and offset delay t3 to the CSPE and correlator blocks. The CSPE block generates the projection operator Ps 3 (1) ⊥ and operates on the data y(1) to produce the processed data y(2′) that has the first and third signals removed. The prime denotes that different signals were cancelled than in the previous processing finger case, i.e., (2) refers to the cancellation of processing fingers 1 and 2 whereas (2′) refers to the cancellation of processing fingers 1 and 3.
P s 3 (1) ⊥ =I−s 3 (1)(s 3 (1) T s 3 (1))−1 s 3 (1) T (26) y (2′) =P s 3 (1) ⊥ y (1) =P s 3 (1) ⊥ P s 1 ⊥ y (27) y (2′) =P s 3 (1) ⊥ s 2 (1)θ2 +P s 3 (1) ⊥ s 3 (1)θ3 +P s 3 (1) ⊥ s 4 (1)θ4 + . . . +P s 3 (1) ⊥ s m−1 (1)θm−1 +P s 3 (1) ⊥ s m (1)θm +P s 3 (1) ⊥ n (28) y (2′) =s 2 (2′)θ2 +s 4 (2′)θ4 + . . . +s m−1 (2′)θm−1 +s m (2′)θm +n (29 )
Nth Processing Finger According to an embodiment of the present invention, without loss of generality, the control block sends the processed data y(k) with k (k<n) signals removed, the product of the corresponding k projection operators
∏ i , j ⁢ ⁢ P s i ( j ) ⊥ and the time offset information tn−1 to the baseline receiver block and y(k) to the CSPE block to effectively find the nth strongest signal with k signals removed. The baseline block calculates an estimate of the tracking parameters of the next strongest signal by correlating with a generated reference signal
s n ( k ) = ∏ i , j ⁢ ⁢ P s i ( j ) ⊥ ⁢ s n and sends the signal and offset delay tn to the CSPE and correlator blocks. The CSPE block generates the projection operator Ps n (k) ⊥ and operates on the data y(k) to produce the processed data y(k+1) that has the nth signal removed.
P s n ( k ) ⊥ = I - s n ( k ) ⁡ ( s n ( k ) T ⁢ s n ( k ) ) - 1 ⁢ s n ( k ) T ( 30 ) y ( k + 1 ) = P s n ( k ) ⊥ ⁢ y ( k ) = ∏ i , j ⁢ ⁢ P s i ( j ) ⊥ ⁢ y ( 31 ) y ( k + 1 ) = P s n ( k ) ⊥ ⁢ s 1 ( k ) ⁢ θ 1 + � ⁢ + P s n ( k ) ⊥ ⁢ s n - 1 ( k ) ⁢ θ n - 1 + P s n ( k ) ⊥ ⁢ s n ( k ) ⁢ θ n + P s n ( k ) ⊥ ⁢ s n + 1 ( k ) ⁢ θ n + 1 + � ⁢ + P s n ( k ) ⊥ ⁢ s m ( k ) ⁢ θ m + P s n ( k ) ⊥ ⁢ n ( 32 ) where k signals have been removed from the first n signals.
y (k+1) =s 1 (k+1)θ1 + . . . +s n−1 (k+1)θn−1 +s n+1 (k+1)θn+1 + . . . +s m (k+1)θm +n (33)
The CSPE block sends the signal sn (k) and y(k) to the Viterbi decoder while y(k+1), Ps (k) ⊥ and tn are sent to the control block. The correlator block calculates a power measurement P and the info term that is subsequently sent to the control block.
EXAMPLE I The following embodiment is the cdmaOne (IS-95) forward link receiver. The cdmaOne serial cancellation CSPE receiver incorporates the coded signal-processing engine (CSPE) into a cdmaOne receiver architecture in which interference cancellation is performed in a serial manner as described above. Specifically, interference cancellation operations of single fingers, e.g., one or more channels from a LOS or multipath signal, are performed in a serial, or cascading, manner, typically ordered in terms of power from highest to lowest. Each processing finger may operate on the received data y or on processed data in which one or more interference signals have been cancelled. The benefit of this serial approach is that a serial receiver processing-finger may track and demodulate a signal that may otherwise be buried beneath the interference and may be undetectable by a baseline receiver. A master control module controls data flow and control signals for all processing fingers. Depending on the power of the signals that are to be acquired, the CSPE may or may not cancel the interference of the previous signal(s).
The generation of S module 780 has a lot of flexibility in terms of its implementation. The channels to be canceled from the data signal may be pre-set as a fixed-size subset of channels or the complete set of channels or it may be dynamically determined from the relative channel amplitude output from Hadamard transform module 770 or another criteria. For example, a threshold may be set, such that all channels above this particular threshold are selected or a fixed number of channels may be chosen such that those channels with the greatest power are selected to be included in the generation of the S matrix. A control module, such as shown in FIG. 5, element 530, also determines which method of cancellation is to be used, i.e., sign information, relative power information for the composite method, no information, or the cancellation method may be fixed by the architecture. Reference signals are generated and used as vectors in the construction of the S matrix. If the input data is processed data, then a projection matrix or product of projection matrices 772 may be applied to the reference signals. The output of module 780 is the S matrix and the projection operator constructed from S that projects a signal onto a subspace orthogonal to the subspace of S. Module 790 applies the new projection operator (denoted by �*�) to the data signal. Processing finger 700 feeds the new projection operator and the processed data y(1) to a control module, such as shown in FIG. 5, element 530.
EXAMPLE II The following embodiment is of the cdma2000 forward link receiver. Modifications have to be made to the cdmaOne embodiment to accommodate features and enhancements made in cdma2000. Quasi-orthogonal (QOF) and concatenated functions may be used to achieve a smaller impact on the number of orthogonal codes available for traffic channels. Variable length Walsh codes are also used to attain higher data rates. Specifically, shorter Walsh codes down to 4 chips in length are used to increase the data rate. The limitation on Walsh codes is a length limit of 128 for 1� rates and 256 for 3� rates, except for the auxiliary pilot and auxiliary transmit diversity pilot channels.
The generation of S, modules 1411 and 1431, have a lot of flexibility in terms of their implementation. The channels to be canceled from the data signal can be pre-set as a fixed-size subset of channels or the complete set of channels or it may be dynamically determined from the relative channel amplitude output from the amplitude estimator modules 1409 and 1429. For example, a threshold may be set, such that all channels above this particular threshold are selected or a fixed number of channels may be chosen such that those with the greatest power are selected to be included in the generation of the S matrix. The control module also determines which method of cancellation is to be used, i.e., sign information, relative power information for the composite method or no information, or it may be fixed in the architecture. Reference signals are generated and used as vectors in the construction of the S matrices. If the input data is processed data, then a projection matrix or product of projection matrices is applied to each of the reference signals. The output of modules 1411 and 1431 is the S matrix and the projection operator constructed from the S matrices that project the signals onto a subspace orthogonal to the subspace of each of the S matrices respectively. Modules 1413 and 1433 apply the new projection operators (denoted by �*�) to the data signals. The processing finger feeds the new projection operators and the processed data yI (1) and yQ (1) to the control module.
FIGS. 16A, 16B, 17A, 17B, 18A and 18B depict several examples of �generation of S� modules. FIGS. 16A and 16B depict the generation of S matrix modules 1600 and 1650 that use no information of bits transmitted or relative signal amplitude. Each channel has a respective selector 1601, 1611, 1651 and 1661 that determines which symbols (channels) will be removed from the data signal. If the data has been processed, i.e., has had interference signals removed, then the appropriate projection matrix or product of projection matrices is applied to each symbol by respective multipliers 1603, 1613, 1653 and 1663. The reference vector output from each selected channel is included as a vector in the interference matrices SI and SQ, 1620 and 1670, respectively. The ordering of the vectors in the S matrices does not matter.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS3742201Feb 22, 1971Jun 26, 1973Raytheon CoTransformer system for orthogonal digital waveformsUS4088955Apr 7, 1975May 9, 1978Baghdady Elie JInterference rejection techniqueUS4309769Feb 25, 1980Jan 5, 1982Harris CorporationMethod and apparatus for processing spread spectrum signalsUS4359738Aug 9, 1977Nov 16, 1982The United States Of America As Represented By The Secretary Of The NavyClutter and multipath suppressing sidelobe canceller antenna systemUS4601046May 15, 1984Jul 15, 1986Halpern Peter HSystem for transmitting data through a troposcatter mediumUS4665401Oct 10, 1980May 12, 1987Sperry CorporationMillimeter wave length guidance systemUS4670885Feb 26, 1985Jun 2, 1987Signatron, Inc.Spread spectrum adaptive antenna interference cancellerUS4713794Feb 22, 1982Dec 15, 1987Raytheon CompanyDigital memory systemUS4780885Jul 15, 1985Oct 25, 1988Paul Haim DFrequency management systemUS4856025Dec 29, 1986Aug 8, 1989Matsushita Electric Industrial Co., Ltd.Method of digital signal transmissionUS4893316Jul 24, 1986Jan 9, 1990Motorola, Inc.Digital radio frequency receiverUS4922506Jan 11, 1988May 1, 1990Sicom CorporationCompensating for distortion in a communication channelUS4933639Feb 13, 1989Jun 12, 1990The Board Of Regents, The University Of Texas SystemAxis translator for magnetic resonance imagingUS4965732Nov 2, 1987Oct 23, 1990The Board Of Trustees Of The Leland Stanford Junior UniversityMethods and arrangements for signal reception and parameter estimationUS5017929Sep 6, 1989May 21, 1991Hughes Aircraft CompanyAngle of arrival measuring techniqueUS5099493Aug 27, 1990Mar 24, 1992Zeger-Abrams IncorporatedMultiple signal receiver for direct sequence, code division multiple access, spread spectrum signalsUS5105435Dec 21, 1990Apr 14, 1992Motorola, Inc.Method and apparatus for cancelling spread-spectrum noiseUS5109390Nov 7, 1989Apr 28, 1992Qualcomm IncorporatedDiversity receiver in a cdma cellular telephone systemUS5119401Nov 19, 1990Jun 2, 1992Nec CorporationDecision feedback equalizer including forward part whose signal reference point is shiftable depending on channel responseUS5136296Jan 2, 1991Aug 4, 1992Max-Planck-Gesellschaft Zur Foerderung Der Wissenschaften E.V.Oblique spaced antenna method and system for measuring atmospheric wind fieldsUS5151919Dec 17, 1990Sep 29, 1992Ericsson-Ge Mobile Communications Holding Inc.Cdma subtractive demodulationUS5218359Jul 28, 1992Jun 8, 1993Kokusai Denshin Denwa Co., Ltd.Adaptive array antenna systemUS5218619Aug 2, 1991Jun 8, 1993Ericsson Ge Mobile Communications Holding, Inc.CDMA subtractive demodulationUS5220687May 28, 1991Jun 15, 1993Pioneer Electronic CorporationRadio receiver having switch for switching between a wide filter and a narrow filterUS5224122Jun 29, 1992Jun 29, 1993Motorola, Inc.Method and apparatus for canceling spread-spectrum noiseUS5237586Mar 25, 1992Aug 17, 1993Ericsson-Ge Mobile Communications Holding, Inc.Rake receiver with selective ray combiningUS5263191Dec 11, 1991Nov 16, 1993Westinghouse Electric Corp.Method and circuit for processing and filtering signalsUS5280472Mar 9, 1992Jan 18, 1994Qualcomm IncorporatedCDMA microcellular telephone system and distributed antenna system thereforUS5305349Apr 29, 1993Apr 19, 1994Ericsson Ge Mobile Communications Inc.Quantized coherent rake receiverUS5325394Mar 3, 1993Jun 28, 1994Motorola, Inc.Method and apparatus for canceling spread-spectrum noiseUS5343493Mar 16, 1993Aug 30, 1994Hughes Aircraft CompanyPersonal assistance system and method for use with a cellular communication systemUS5343496Sep 24, 1993Aug 30, 1994Bell Communications Research, Inc.Interference suppression in CDMA systemsUS5347535Mar 3, 1993Sep 13, 1994Kokusai Denshin Denwa Co., Ltd.CDMA communication systemUS5353302Feb 3, 1993Oct 4, 1994At&T Bell LaboratoriesSignal despreader for CDMA systemsUS5377183Apr 11, 1994Dec 27, 1994Ericsson-Ge Mobile Communications Inc.Calling channel in CDMA communications systemUS5386202Nov 3, 1993Jan 31, 1995Sicom, Inc.Data communication modulation with managed intersymbol interferenceUS5390207Mar 24, 1994Feb 14, 1995Novatel Communications Ltd.Pseudorandom noise ranging receiver which compensates for multipath distortion by dynamically adjusting the time delay spacing between early and late correlatorsUS5394110Feb 2, 1994Feb 28, 1995Nec CorporationDemodulation system having adaptive matched filter and decision feedback equalizerUS5396256Oct 27, 1993Mar 7, 1995Atr Optical & Radio Communications Research LaboratoriesApparatus for controlling array antenna comprising a plurality of antenna elements and method thereforUS5437055Jun 3, 1993Jul 25, 1995Qualcomm IncorporatedAntenna system for multipath diversity in an indoor microcellular communication systemUS5440265Sep 14, 1994Aug 8, 1995Sicom, Inc.Differential/coherent digital demodulator operating at multiple symbol pointsUS5448600Aug 12, 1994Sep 5, 1995Matra CommunicationMethod for selecting propagation paths retained for receiving messages transmitted by CDMA radiocommunicationUS5481570Oct 20, 1993Jan 2, 1996At&T Corp.Block radio and adaptive arrays for wireless systemsUS5506865Nov 21, 1994Apr 9, 1996Qualcomm IncorporatedPilot carrier dot product circuitUS5513176Aug 27, 1993Apr 30, 1996Qualcomm IncorporatedDual distributed antenna systemUS5533011Dec 23, 1994Jul 2, 1996Qualcomm IncorporatedDual distributed antenna systemUS5553098Apr 12, 1994Sep 3, 1996Sicom, Inc.Demodulator with selectable coherent and differential dataUS5602833Dec 19, 1994Feb 11, 1997Qualcomm IncorporatedMethod and apparatus for using Walsh shift keying in a spread spectrum communication systemUS5644592Apr 24, 1995Jul 1, 1997California Institute Of TechnologyParallel interference cancellation for CDMA applicationsUS5736964Feb 16, 1996Apr 7, 1998Motorola, Inc.In a wireless communication systemUS5787130Dec 10, 1996Jul 28, 1998Motorola Inc.Method and apparatus for canceling interference in a spread-spectrum communication systemUS5844521Dec 2, 1996Dec 1, 1998Trw Inc.Geolocation method and apparatus for satellite based telecommunications systemUS5859613Aug 30, 1996Jan 12, 1999Harris CorporationSystem and method for geolocating plural remote transmittersUS5872540Jun 26, 1997Feb 16, 1999Electro-Radiation IncorporatedDigital interference suppression system for radio frequency interference cancellationUS5872776Nov 22, 1996Feb 16, 1999Yang; Lin-LangInformation processing systemUS5894500Jun 13, 1997Apr 13, 1999Motorola, Inc.Method and apparatus for canceling signals in a spread-spectrum communication systemUS5926761Jun 11, 1996Jul 20, 1999Motorola, Inc.Method and apparatus for mitigating the effects of interference in a wireless communication systemUS5930229Mar 10, 1997Jul 27, 1999Nec CorporationInterference canceller for CDMAUS5953369Jun 10, 1997Sep 14, 1999Nec CorporationDS-CDMA receiver with multi-stage serial interference cancelers using power level information appended to data blocksUS5978413Aug 28, 1995Nov 2, 1999Bender; Paul E.Method and system for processing a plurality of multiple access transmissionsUS5995499Oct 5, 1995Nov 30, 1999Nokia Telecommunications OySignal detection in a TDMA systemUS6002727Oct 16, 1997Dec 14, 1999Matsushita Electric Industrial Co., Ltd.Interference signal cancellation systemUS6014373Sep 29, 1997Jan 11, 2000Interdigital Technology CorporationSpread spectrum CDMA subtractive interference canceler systemUS6018317Nov 22, 1996Jan 25, 2000Trw Inc.Cochannel signal processing systemUS6032056Jun 9, 1998Feb 29, 2000Metawave Communications CorporationCellular system signal conditionerUS6088383Mar 5, 1997Jul 11, 2000Kokusai Denshin Denwa Kabushiki KaishaSpread-spectrum signal demodulatorUS6101385Oct 9, 1997Aug 8, 2000Globalstar L.P.Satellite communication service with non-congruent sub-beam coverageUS6104712Feb 22, 1999Aug 15, 2000Robert; Bruno G.Wireless communication network including plural migratory access nodesUS6115409Jun 21, 1999Sep 5, 2000Envoy Networks, Inc.Integrated adaptive spatial-temporal system for controlling narrowband and wideband sources of interferences in spread spectrum CDMA receiversUS6127973Apr 18, 1997Oct 3, 2000Korea Telecom Freetel Co., Ltd.Signal processing apparatus and method for reducing the effects of interference and noise in wireless communication systemsUS6131013Jan 30, 1998Oct 10, 2000Motorola, Inc.Method and apparatus for performing targeted interference suppressionUS6137788Jun 12, 1996Oct 24, 2000Ntt Mobile Communications Network, Inc.CDMA demodulating apparatusUS6141332Mar 29, 1999Oct 31, 2000Interdigital Technology CorporationOrthogonal code synchronization system and method for spread spectrum CDMA communicationsUS6154443Aug 11, 1998Nov 28, 2000Industrial Technology Research InstituteFFT-based CDMA RAKE receiver system and methodUS6157685Dec 19, 1997Dec 5, 2000Fujitsu LimitedInterference canceller equipment and interference cancelling method for use in a multibeam-antenna communication systemUS6157842Oct 16, 1997Dec 5, 2000Telefonaktiebolaget Lm EricssonSystem and method for positioning a mobile station in a CDMA cellular systemUS6157847Jun 29, 1999Dec 5, 2000Lucent Technologies Inc.Base station system including parallel interference cancellation processorUS6163696Dec 31, 1996Dec 19, 2000Lucent Technologies Inc.Mobile location estimation in a wireless communication systemUS6166690Jul 2, 1999Dec 26, 2000Sensor Systems, Inc.Adaptive nulling methods for GPS reception in multiple-interference environmentsUS6172969Jan 28, 1998Jan 9, 2001Oki Electric Industry Co., Ltd.CDMA receiver employing successive cancellation of training-signal interferenceUS6175587Dec 30, 1997Jan 16, 2001Motorola, Inc.Communication device and method for interference suppression in a DS-CDMA systemUS6192067Dec 19, 1997Feb 20, 2001Fujitsu LimitedMultistage interference cancellerUS6201799May 1, 1997Mar 13, 2001Lucent Technologies, IncPartial decorrelation for a coherent multicode code division multiple access receiverUS6215812Dec 16, 1999Apr 10, 2001Bae Systems Canada Inc.Interference canceller for the protection of direct-sequence spread-spectrum communications from high-power narrowband interferenceUS6219376Feb 21, 1998Apr 17, 2001Topcon Positioning Systems, Inc.Apparatuses and methods of suppressing a narrow-band interference with a compensator and adjustment loopsUS6222828Oct 30, 1996Apr 24, 2001Trw, Inc.Orthogonal code division multiple access waveform format for use in satellite based cellular telecommunicationsUS6230180Oct 14, 1998May 8, 2001Conexant Systems, Inc.Digital signal processor configuration including multiplying units coupled to plural accumlators for enhanced parallel mac processingUS6233229Nov 27, 1995May 15, 2001Nokia Telecommunications OyMethod of allocating frequency bands to different cells, and TDMA cellular radio systemUS6233459Mar 18, 1998May 15, 2001The Atlantis Company, Limited, JapanSystem for providing Geolocation of a mobile transceiverUS6240124Nov 2, 1999May 29, 2001Globalstar L.P.Closed loop power control for low earth orbit satellite communications systemUS6252535Aug 20, 1998Jun 26, 2001Data Fusion CorporationMethod and apparatus for acquiring wide-band pseudorandom noise encoded waveformsUS6256336Jun 13, 1997Jul 3, 2001Siemens AktiengesellschaftMethod and apparatus for detecting items of information transmitted according to the DS-CDMA principle in a receiver apparatusUS6259688Mar 25, 1999Jul 10, 2001Interdigital Technology CorporationSpread spectrum CDMA subtractive interference canceler systemUS6263208May 28, 1999Jul 17, 2001Lucent Technologies Inc.Geolocation estimation method for CDMA terminals based on pilot strength measurementsUS6266529May 13, 1998Jul 24, 2001Nortel Networks LimitedMethod for CDMA handoff in the vicinity of highly sectorized cellsUS6275186Dec 10, 1999Aug 14, 2001Samsung Electronics Co., Ltd.Device and method for locating a mobile station in a mobile communication systemUS6278726Sep 11, 2000Aug 21, 2001Interdigital Technology CorporationInterference cancellation in a spread spectrum communication systemUS6282231Dec 14, 1999Aug 28, 2001Sirf Technology, Inc.Strong signal cancellation to enhance processing of weak spread spectrum signalUS6282233Apr 6, 1999Aug 28, 2001Nec CorporationMulti-user receiving apparatus and CDMA communication systemUS6771988 *Dec 26, 2000Aug 3, 2004Kabushiki Kaisha ToshibaRadio communication apparatus using adaptive antenna* Cited by examinerNon-Patent CitationsReference1Affes et al., Interference Subspace Rejection: A Framework for Multiuser Detection in Wideband CDMA, IEEE Journal on Selected Areas in Communications, Feb. 2002, vol. 20, No. 2.2Alexander et al., A Linear Receiver for Coded Multiuser CDMA, IEEE Transactions on Communications, May 1997, vol. 45, No. 5.3Behrens et al., Parameter Estimation in the Presence of Low Rank Noise, pp. 341-344, Maple Press, 1988.4Behrens et al., Signal Processing Applications of Oblique Projection Operators, IEEE Transactions on Signal Processing, Jun. 1994, vol. 42, No. 6.5Behrens, Subspace Signal Processing in Structured Noise, UMI Dissertation Services, Jun. 1990, Ann Arbor, MI, US.6Best, Phase-Locked Loops-Design, Simulation, and Applications, pp. 251-287, McGraw-Hill, 1999.7Cheng, et al., Spread-Spectrum Code Acquisition in the Presence of Doppler Shift and Data Modulation, IEEE Transactions on Communications, Feb. 1990, vol. 38, No. 2.8Frankel et al., High-performance photonic analogue digital converter, Electronic Letters, Dec. 4, 1997, vol. 33, No. 25.9Garg, et al., Wireless and Personal Communications Systems, 1996, pp. 79-151, Prentice Hall, Upper Saddle River, NJ, US.10Halper et al., Digital-to-Analog Conversio n by Pulse-Count Modulation Methods, IEEE Transactions on Instrumentation and Measurement, Aug. 1996, vol. 45, No. 4.11Iltis, Multiuser Detection of Quasisynchronous CDMA Signals Using Linear Decorrelators, IEEE Transactions on Communications, Nov. 1996, vol. 44, No. 11.12Kaplan, Understanding GPS-Principles and Applications, 1996, pp. 83-236, Artech House, Norwood, MA, US.13Kohno, et al., Cancellation Techniques of Co-Channel Interference in Asynchronous Spread Spectrum Multiple Access Systems, May 1983, vol. J 56-A. No. 5.14Lin et al., Digital Filters for High Performance Audio Delta-sigma Analog-to-digital and Digital-to-analog Conversions, Proceedings of ICSP, Crystal Semiconductor Corporation, 1996, Austin, TX, US.15Lupas, et al. Near-Far Resistance of Multiuser Detectors in Asynchronous Channels, IEEE Transactions on Communications, Apr. 1990, vol. 38, No. 4.16Lupas, et al., Linear Multiuser Detectors for Synchronous Code-Division Multiple-Access Channels, IEEE Transactions on Information Theory, Jan. 1989, vol. 35, No. 1.17Mitra, et al., Adaptive Decorrelating Detectors for CDMA Systems, Accepted for Wireless Communications Journal, Accepted May 1995.18Mitra, et al., Adaptive Receiver Algorithms for Near-Far Resistant CDMA, IEEE Transactions of Communications, Apr. 1995.19Ortega et al., Analog to Digital and Digital to Analog Conversion Based on Stochastic Logic, IEEE 0-7803-3026-9/95, 1995.20Price et al., A Communication Technique for Multipath Channels, Proceedings to the IRE, 1958, vol. 46, The Institute of Radio Engineers, New York, NY, US.21Rappaport, Wireless Communications-Principles & Practice, 1996, pp. 518-533, Prentice Hall, Upper Saddle River, NJ, US.22Scharf, et al., Matched Subspace Detectors, IEEE Transactions on Signal Processing, Aug. 1994, vol. 42, No. 8.23Scharf, Statistical Signal Processing-Detection, Estimation, and Time Series Analysis, 1990, pp. 23-75 and 103-178, Addison-Wesly, Reading, MA, US.24Schlegel et al., Coded Asynchronous CDMA and Its Efficient Detection, IEEE Transactions on Information Theory, Nov. 1998, vol. 44, No. 7.25Schlegel et al., Multiuser Projection Receivers, IEEE Journal on Selected Areas in Communications, Oct. 1996, vol. 14, No. 8.26Schlegel et al., Projection Receiver: A New Efficient Multi-User Detector, IEEE, 1995, 0-7803-2509-5/95.27Schneider, Optimum Detection of Code Division Multiplexed Signals, IEEE Transactions on Aerospace and Electronic Systems, Jan. 1979, vol. AES-15 No. 1.28Stimson, Introduction to Airborne Radar 2nd edition, 1998, pp. 163-176 and 473-491, SciTech Publishing, Mendham, NJ, US.29Thomas, Thesis for the Doctor of Philosophy Degree, UMI Dissertation Services, Jun. 1996, Ann Arbor, MI, US.30Verdu, Mimimum Probability of Error for Asynchronous Gaussian Multiple-Access Channels, IEEE Transactions on Information Theory, Jan. 1986, vol. IT-32, No. 1.31Viterbi, CDMA-Principles of Spread Spectrum Communication, 1995, pp. 11-75 and 179-233, Addison-Wesley, Reading, MA, US.32Viterbi, Very Low Rate Convolutional Codes for Maximum Theoretical Performance of Spread Spectrum Multiple-Access Channels, IEEE Journal on Selected Areas in Communications, May 1990, vol. 8, No. 4.33Xie et al. , A family of Suboptimum Detectors for Coherent Multiuser Communications, IEEE Journal on Selected Areas in Communications, May 1990, vol. 8, No. 4.Classifications U.S. Classification375/346, 375/E01.025, 375/E01.024, 375/E01.032International ClassificationH04J11/00, G01S5/10, G01S1/00, G01S19/48, G01S5/02, G01S5/14Cooperative ClassificationH04B1/7105, H04B2201/70701, H04B2001/70706, G01S5/0215, H04B1/7103, G01S5/10, H04B1/7075, H04B2201/70715, H04B1/709, G01S19/22, H04B1/7117European ClassificationH04B1/7103, H04B1/7105, G01S19/22, G01S5/02A2Legal EventsDateCodeEventDescriptionApr 9, 2014ASAssignmentFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:RAMBUS INC.;REEL/FRAME:032642/0115Effective date: 20140317Owner name: III HOLDINGS 1, LLC, DELAWAREMar 14, 2014SULPSurcharge for late paymentOct 17, 2011FPAYFee paymentYear of fee payment: 4Jul 19, 2010ASAssignmentFree format text: CORRECTIVE ASSIGNMENT TO CORRECT THE ASSIGNEE INFORMATION PREVIOUSLY RECORDED ON REEL 024202 FRAME0630. 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