Method and apparatus to provide multiple-mode spatial processing to a terminal unit

• US 7,277,679 B1
• Filed: 10/07/2002
• Issued: 10/02/2007
• Est. Priority Date: 09/28/2001
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: ArrayComm LLC (Ygomi LLC)
• Inventors: Kasapi, Athanasios A., Barratt, Craig H.
• Primary Examiner(s): Anderson, Matthew D.
• Assistant Examiner(s): PEREZ, ANGELICA
• Application Number:
  US10/265,896
• Time in Patent Office: 1,821 Days
• Field of Search: 455/101, 455132-138, 375/347
• US Class Current: 455/101
• CPC Class Codes: H04B 17/24 with feedback of measurements to the transmitter
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04B 7/084 Equal gain combining, only phase adjustments antenna beam scanning or forming by phase or amplitude control H01Q3/26, e.g. phased arrays
• CPC Class Codes: H04B 7/0842 Weighted combining
• CPC Class Codes: H04B 7/0851 using training sequences or error signal minimizing error signal H04B7/0854
• CPC Class Codes: H04B 7/0857 using maximum ratio combining techniques, e.g. signal-to- interference ratio [SIR], received signal strenght indication [RSS]
• CPC Class Codes: H04B 7/0868 Hybrid systems, i.e. switching and combining
• CPC Class Codes: H04B 7/0871 using different reception schemes, at least one of them being a diversity reception scheme
• CPC Class Codes: H04B 7/0874 using subgroups of receive antennas
• CPC Class Codes: H04B 7/0877 switching off a diversity branch, e.g. to save power
• CPC Class Codes: H04B 7/088 using beam selection
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity

Abstract

Methods and apparatuses, including computer program products, for spatial processing in a remote terminal unit. One embodiment is a wireless remote terminal receiver in a wireless terminal unit for operation in a wireless communication system. The wireless remote terminal receiver includes an antenna array, and a receive processing unit to process signals received by the antenna array by applying a selected spatial processing mode of a plurality of spatial processing modes. The modes include one or more modes of one or more spatial processing methods. The receiver also includes a selector to select the spatial processing mode from the plurality of spatial processing modes. The selecting includes selecting the spatial processing method in the case that the set of spatial processing modes are of more than one spatial processing method.

Claims

1. A wireless remote terminal receiver in a wireless terminal unit, the wireless remote terminal receiver comprising:

an antenna array;

a receive processing unit coupled to the antenna array to process signals received by the antenna array by applying a selected spatial processing mode of a plurality of spatial processing modes of one or more spatial processing methods; and

a selector coupled to the receive processing unit to select the spatial processing mode from the plurality of spatial processing modes, including selecting the spatial processing method in the case that the set of spatial processing modes are of more than one spatial processing method.

2. A wireless remote terminal receiver as recited in claim 1, wherein the set of spatial processing modes includes at least one of:

a group of one or more modes of a delay and add processing method;

a group of one or more modes of a switched antenna diversity spatial processing method;

a group of one or more modes of an adaptive smart antenna spatial processing method using a maximum ratio combining strategy determining method;

a group of one or more modes of an adaptive smart antenna spatial processing method using a known signal property strategy determining method;

a group of one or more modes of an adaptive smart antenna spatial processing method using a known training signal strategy determining method; and

a group of one or more modes of a switched beam smart antenna spatial processing method.

3. A wireless remote terminal receiver as recited in claim 2, wherein the set of spatial processing modes includes one or more modes of at least two spatial processing methods.

4. A wireless remote terminal receiver as recited in claim 2, wherein at least one of the groups includes different modes of a spatial processing method that has an associated frequency of determining the spatial processing strategy, and wherein the spatial processing modes in the group have different associated frequencies of determining the strategy, such that selecting from amongst the different modes in the group provides modes that consume different amounts of overall computational power.

5. A wireless remote terminal receiver as recited in claim 2, wherein the processing unit includes a plurality of receive paths, one coupled to each antenna to accept the signal from the antenna, at least some of the receive paths switchable between a first operating mode and a second operating mode according to a power control signal, the first operating mode consuming more power than the second operating mode, the received further including:

a switchable power supply responsive to the power control signal and coupled to the receive paths to provide power to each receive path in the processing unit according to the power control signal,

wherein the power control signal depends on the operating mode such that some of the spatial processing modes differ in the amount of power consumption by having the receive paths operate at different operating modes.

6. A wireless remote terminal receiver as recited in claim 5, wherein the first operating mode is on and the second operating mode is off such that the switchable power supply switches none or more of the switchable receive paths to off depending on the selected spatial processing mode.

7. A wireless remote terminal receiver as recited in claim 2,

wherein the set of spatial processing modes includes a group of one or more modes of a delay and add processing method,

wherein the antenna array includes a first antenna and one or more additional antennas,

wherein when the selector selects the delay and add method, the receive processing unit is further to delay and add process the signals received at the first antenna and at least one of the additional antennas, the delay and add processing forming a sum signal being the sum of the signal received at the first antenna and delayed versions of respective signals received at the one or more additional antennas, and

wherein the receive processing unit further includes a processor accepting the sum signal when the selector selects the delay and adding method, the processor having multipath combining capabilities.

8. A wireless remote terminal receiver as recited in claim 7,

wherein the set of spatial processing modes includes at least one additional group of one or more modes of an additional processing method, and

wherein the processing unit includes a plurality of receive paths, one coupled to each antenna to accept the signal from the antenna, at least some of the receive paths switchable between a first operating mode and a second operating mode according to a power control signal, the first operating mode consuming more power than the second operating mode, the received further including:

a switchable power supply responsive to the power control signal and coupled to the receive paths to provide power to each receive path in the processing unit according to the power control signal,

wherein the power control signal depends on the operating mode such that some of the modes differ in the amount of power consumption by having the receive paths operate at different operating modes, and

wherein the delay and add processing consumes less power than at least one of the other additional spatial processing mode groups.

9. A wireless remote terminal receiver as recited in claim 7, wherein the processing unit includes:

a plurality of receive paths, one coupled to each antenna to accept the signal from the antenna, each receive path including an intermediate frequency section, the receive paths accepting signals from the one or more additional antennas including a delay unit in the intermediate frequency section to delay each signal by a respective predetermined amount, and

an adder accepting signals from the first antenna and delayed signals from the one or more additional antennas, the adder to form the sum signal.

10. A wireless remote terminal receiver as recited in claim 7,

wherein the processing unit includes:

a plurality of receive paths, one coupled to each antenna to accept the signal from the antenna, each receive path including an analog to digital converter to form a digitized signal from the respective antenna,

one or more respective digital delay element having an input coupled to the digital output of each of the receive paths accepting signals from the one or more additional antennas, digital delay elements introducing a respective predetermined delay to each digitized signal from the one or more additional antennas, each digital delay element having an output, and

a digital adder having a set of inputs coupled to the outputs of each digital delay element and of the receive path of the first antenna, the adder to form the sum signal from the outputs of the receive paths.

11. A wireless remote terminal receiver as recited in claim 7, wherein the processing unit includes:

a plurality of receive paths, one coupled to each antenna to accept the signal from the antenna, each including a downconverter to convert a radio frequency signal from its respective antenna to an intermediate frequency signal, the receive paths accepting signals from the one or more additional antennas including a delay unit after the downconverter to delay each signal by a respective predetermined amount, the first receive path including an analog adder having a set of inputs, one input coupled to the output of the downconverter of the first receive path and to the outputs of the respective delay units, the adder forming the sum signal, such that the first receive path further processes the sum signal, and the receive paths other than the first need less power to operate than the first receive path.

12. A wireless remote terminal receiver as recited in claim 3, wherein the set of spatial processing modes includes a plurality of modes of a switched diversity method that periodically selects the best antenna, and wherein at least some of the different switched diversity modes differ by how often the best antenna is selected.

13. A wireless remote terminal receiver as recited in claim 3,

wherein the set of spatial processing modes includes one or more modes of a switched diversity method that periodically selects the best antenna,

wherein the processing unit includes a plurality of receive paths, one coupled to each antenna to accept the signal from the antenna, at least some of the receive paths switchable on or off, and

wherein all receive paths but one are switched off when the wireless remote terminal receiver operates under at least one of the switched diversity modes.

14. A wireless remote terminal receiver as recited in claim 2, wherein the set of spatial processing modes includes a plurality of modes of an adaptive smart antenna spatial processing method that periodically determines a smart antenna processing strategy, and wherein at least some of the different adaptive smart antenna modes differ by how often the smart antenna processing strategy is determined.

15. A wireless remote terminal receiver as recited in claim 3,

wherein the processing unit includes a plurality of receive paths, one coupled to each antenna to accept the signal from the antenna, at least some of the receive paths switchable on or off, and

wherein, for one or more of the provided methods, different modes for a selected method differ by how many receive paths are on.

16. A wireless remote terminal receiver as recited in claim 2, further comprising a memory to store instructions for spatial processing according to one or more of the spatial processing methods.

17. A wireless remote terminal receiver as recited in claim 2, further comprising:

a user interface including a manual mode selector to manually select the spatial processing mode or no spatial processing.

18. A wireless remote terminal receiver as recited in claim 2, wherein the selector is responsive to signals received at the remote terminal unit from a communicating remote device, such that the remote device remotely selects the spatial processing mode.

19. A wireless remote terminal receiver as recited in claim 2, wherein the selector automatically selects the spatial processing mode according to one or more selection criteria.

20. A wireless remote terminal receiver as recited in claim 19, wherein the spatial processing mode selected by the selector remains until the end of a communication with a remote device or until communication with the remote device fails.

21. A wireless remote terminal receiver as recited in claim 20, further comprising:

a circuit to measure the quality of reception,

wherein an indication of failure of communication is that the quality of reception falls below a predefined level.

22. A wireless remote terminal receiver as recited in claim 19, wherein the one or more criteria include one or more criteria from a set consisting of one or more protocol-based selection criteria, one or more performance-based selection criteria, and one or more operational-based selection criteria.

23. A wireless remote terminal receiver as recited in claim 19, wherein the one or more performance-based selection criteria include a measure of the quality of reception.

24. A wireless remote terminal receiver as recited in claim 19, wherein the one or more protocol-based selection criteria include the type of a wireless communication system the wireless terminal unit operates in.

25. A wireless remote terminal receiver as recited in claim 19, wherein the remote terminal unit and a wireless communication system the wireless terminal unit operates in operate according to a multi-state protocol, and wherein the one or more operational-based criteria include the current state of the protocol the remote terminal unit is in.

26. A wireless remote terminal receiver as recited in claim 19, further comprising:

a circuit to measure the quality of reception,

wherein the one or more criteria include the quality of reception.

27. A wireless remote terminal receiver as recited in claim 26, wherein the quality measure circuit measures one of the received signal strength indication (RSSI), the signal-to-noise (SNR) ratio, the carrier-to-interference ratio (CIR), the bit error rate (BER), the frame error rate (FER), and the spatial correlation between a transmitting remote transmitting device and an interfering remote transmitting device.

28. A wireless remote terminal receiver as recited in claim 19, wherein the one or more criteria include one or more protocol-based criteria including a type of wireless communication system the remote terminal unit operates in.

29. A wireless remote terminal receiver as recited in claim 19, wherein the remote terminal unit and a wireless communication system the wireless terminal unit operates in operate according to a multi-state protocol, and wherein one or more criteria include one or more operational-based criteria including the current state of the protocol the remote terminal unit is in.

30. A wireless remote terminal receiver as recited in claim 19, further comprising:

a memory coupled to the selector and storing a table, each entry containing a reference to one of the spatial processing modes and indexed by a function of the one or more criteria,

such that the automatic selecting indexes the table to select the spatial processing mode.

31. A wireless remote terminal receiver as recited in claim 19, wherein the one or more criteria include at least two criteria, the wireless remote terminal receiver further comprising:

a memory coupled to the selector and storing a set of tables, each entry containing a references to one of the tables or to one of the spatial processing modes and indexed by a function of the one of the criteria,

such that the selection indexes the set of table to select the spatial processing mode.

32. A wireless remote terminal receiver as recited in claim 19, wherein the selector adaptively selects the processing mode by selecting a first spatial processing mode to process received signals for a first time period, selecting a different second spatial processing mode for processing received signals for a second time period, comparing the performance of the first and second modes, and thereafter selecting the better performing spatial processing mode.

33. A wireless remote terminal receiver as recited in claim 32, wherein the selector selects the first spatial processing mode randomly from the available spatial processing modes.

34. A wireless remote terminal receiver as recited in claim 32, wherein the selector selects the first spatial processing mode according to a first criterion.

35. A wireless remote terminal receiver as recited in claim 34, wherein the first criterion is a performance criterion.

36. A wireless remote terminal receiver as recited in claim 34, wherein the first criterion is based at least on an operational state of the remote terminal unit.

37. A wireless remote terminal receiver as recited in claim 32, wherein the relative lengths of the first and second time periods, called the duty cycle, is pre-defined.

38. A wireless remote terminal receiver as recited in claim 32, wherein the relative lengths of the first and second time periods, called the duty cycle, is selected according one or more duty cycle selection criteria.

39. A wireless remote terminal receiver as recited in claim 32, wherein the relative lengths of the first and second time periods, called the duty cycle, is selected according to the type of error correcting coding used in the received signals such that communication is likely to continue even if one or more errors occur in one of the time periods.

40. A wireless remote terminal receiver as recited in claim 19, wherein the selector initially selects a primary spatial processing and then adaptively selects the processing mode according to a duty cycle process to compare one or more different spatial processing modes with the primary spatial processing mode at different times.

41. A wireless remote terminal receiver as recited in claim 40, wherein the duty cycle process includes repeating the steps of:

using the primary spatial processing mode to process received signals for a first time period,

selecting a different second spatial processing mode and processing received signals using the second mode for a second time period according to a selected relative length of the first and second time periods, called the duty cycle,

comparing the performance of the primary and second modes; and

selecting the better performing spatial processing mode as the primary mode.

42. A wireless remote terminal receiver as recited in claim 41, wherein the selected duty cycle is pre-defined.

43. A wireless remote terminal receiver as recited in claim 41, wherein the selected duty cycle is selected according to a duty cycle selection criterion.

44. A wireless remote terminal receiver as recited in claim 43, wherein the selected duty cycle is selected according to the type of error correcting coding used in the received signals such that communication is likely to continue even if one or more errors occur in one of the time periods.

45. A wireless remote terminal receiver as recited in claim 43, wherein the selected duty cycle is selected by a remote device in communication with the remote terminal unit.

46. A wireless remote terminal receiver as recited in claim 41, wherein the selector selects the first spatial processing mode according to a first criterion.

47. A wireless remote terminal receiver as recited in claim 41, wherein the selector selects the first spatial processing mode randomly from among available spatial processing modes.

48. A wireless remote terminal receiver as recited in claim 46, wherein the first criterion is a performance criterion.

49. A wireless remote terminal receiver as recited in claim 46, wherein the first criterion is based at least on an operational state of the remote terminal unit.

50. A wireless remote terminal receiver as recited in claim 46, wherein the selected duty cycle is selected according to one or more duty cycle selection criteria.

51. A wireless remote terminal receiver as recited in claim 50, wherein the duty cycle selection criteria initially include the same criterion as the first selection criterion, and thereafter include the relative performance in the first and second time periods, such that the duty cycle is varied according to the relative performance.

52. A wireless remote terminal receiver as recited in claim 50, wherein the duty cycle selection criteria include the type of error correcting coding used in the received signals such that communication is likely to continue even if one or more errors occur in the second time period.

53. A wireless remote terminal receiver as recited in claim 17, wherein the set of spatial processing modes includes one or more modes of at least two spatial processing methods.

54. A wireless remote terminal receiver as recited in claim 53, wherein activating manual mode selector selects a spatial processing method and mode that is known to provide better reception.

55. A wireless remote terminal receiver as recited in claim 17, wherein at least one of the groups includes different modes of a spatial processing method that has an associated frequency of determining the spatial processing strategy, and wherein the spatial processing modes in the group have different associated frequencies of determining the strategy, such that selecting from amongst the different modes in the group provides modes that consume different amounts of overall computational power.

56. A wireless remote terminal receiver as recited in claim 17, wherein the processing unit includes a plurality of receive paths, one coupled to each antenna to accept the signal from the antenna, at least some of the receive paths switchable between a first operating mode and a second operating mode according to a power control signal, the first operating mode consuming more power than the second operating mode, the received further including:

a switchable power supply responsive to the power control signal and coupled to the receive paths to provide power to each receive path in the processing unit according to the power control signal,

wherein the power control signal depends on the operating mode such that some of the spatial processing modes differ in the amount of power consumption by having the receive paths operate at different operating modes.

57. A wireless remote terminal receiver as recited in claim 19, wherein the set of spatial processing modes includes one or more modes of at least two spatial processing methods.

58. A wireless remote terminal receiver as recited in claim 19, wherein at least one of the groups includes different modes of a spatial processing method that has an associated frequency of determining the spatial processing strategy, and wherein the spatial processing modes in the group have different associated frequencies of determining the strategy, such that selecting from amongst the different modes in the group provides modes that consume different amounts of overall computational power.

59. A wireless remote terminal receiver as recited in claim 19, wherein the processing unit includes a plurality of receive paths, one coupled to each antenna to accept the signal from the antenna, at least some of the receive paths switchable between a first operating mode and a second operating mode according to a power control signal, the first operating mode consuming more power than the second operating mode, the received further including:

a switchable power supply responsive to the power control signal and coupled to the receive paths to provide power to each receive path in the processing unit according to the power control signal,

wherein the power control signal depends on the operating mode such that some of the spatial processing modes differ in the amount of power consumption by having the receive paths operate at different operating modes.

60. A wireless remote terminal receiver in a remote terminal unit, the wireless remote terminal receiver comprising:

a plurality of antennas, including a first antenna and one or more additional antennas;

a receive processing unit coupled to the antennas to process the signals received at the antennas, including a delay and add processing unit to process the signals received at the first antenna and at one or more of the additional antennas, the delay and add processing unit to form a sum signal being the sum of the signal received at the first antenna and delayed versions of respective signals received at the one or more additional antennas, the receive processor further including a processor accepting the sum signal, the processor having multipath combining capabilities and forming a received signal, the receive processing unit further including a receive electronics unit, the receive processing unit to apply a selected spatial processing mode to the signals, the selected spatial processing mode being of a plurality of spatial processing modes, including one or more modes of one or more spatial processing methods.

61. A wireless remote terminal receiver as recited in claim 60, wherein the electronics unit includes:

a plurality of receive paths, one coupled to each antenna to accept the signal from the antenna, each including a downconverter to convert a radio frequency signal from its respective antenna to an intermediate frequency signal, the receive paths accepting signals from the one or more additional antennas including a delay unit after the downconverter to delay each signal by a respective predetermined amount,

an adder with inputs coupled to the outputs of the first receive path and the receive paths accepting signals from the one or more additional antennas, the adder to form the sum signal.

62. A wireless remote terminal receiver as recited in claim 60,

wherein the electronics unit includes:

a plurality of receive paths, one coupled to each antenna to accept the signal from the antenna, each receive path including an analog to digital converter to form a digitized signal from the respective antenna,

one or more respective digital delay element having an input coupled to the digital output of each of the receive paths accepting signals from the one or more additional antennas, digital delay elements introducing a respective predetermined delay to each digitized signal from the one or more additional antennas, each digital delay element having an output, and

a digital adder having a set of inputs coupled to the outputs of each digital delay element and of the receive path of the first antenna, the adder to form the sum signal from the outputs of the receive paths.

63. A wireless remote terminal receiver as recited in claim 60, wherein the electronics unit includes:

a plurality of receive paths, one coupled to each antenna to accept the signal from the antenna, each including a downconverter to convert a radio frequency signal from its respective antenna to an intermediate frequency signal, the receive paths accepting signals from the one or more additional antennas including a delay unit after the downconverter to delay each signal by a respective predetermined amount, the first receive path including an analog adder having a set of inputs, one input coupled to the output of the downconverter of the first receive path and to the outputs of the respective delay units, the adder forming the sum signal,

such that the first receive path further processes the sum signal, and the receive paths other than the first need less power to operate than the first receive path.

64. A wireless remote terminal receiver as recited in claim 60, wherein the electronics unit includes:

a delay and add processor including;

one or more radio frequency delay elements having an input coupled to the one or more additional antennas, and

an analog adder with inputs coupled to the outputs of the first antenna and of the delay elements, the adder to form the sum signal,

a receive path having an input coupled to the output of the adder to accept the sum signal, the receive path including a downconverter to convert the radio frequency sum signal to an intermediate frequency signal, and an analog to digital converter to form a digitized sum signal for further processing by the processor.

65. A wireless remote terminal receiver comprising:

a plurality of antennas;

a receive processing unit coupled to the antennas to apply a selected spatial processing mode to the signals received at the antennas, the selected spatial processing mode being of a plurality of spatial processing modes, including one or more modes of one or more spatial processing methods.

66. A wireless remote terminal receiver in a remote terminal unit, the wireless remote terminal receiver including a plurality of antennas, the wireless remote terminal receiver comprising:

means for providing a plurality of spatial processing modes, including one or more modes of one or more spatial processing methods;

means for selecting a spatial processing mode from the provided plurality of antennas; and

means for processing the signals received at the antennas by the selected spatial processing mode.

67. A wireless remote terminal receiver as recited in claim 66,

wherein the means for selecting selects the spatial processing method in the case that more than one spatial processing method is provided, and

wherein the means for processing the received signals applies a spatial processing method and a spatial processing mode thereof selected from the plurality of modes.

68. A wireless remote terminal receiver as recited in claim 67, wherein the set of spatial processing modes includes at least one of:

a group of one or more modes of a delay and add processing method;

a group of one or more modes of a switched antenna diversity spatial processing method;

a group of one or more modes of an adaptive smart antenna spatial processing method using a maximum ratio combining strategy determining method;

a group of one or more modes of an adaptive smart antenna spatial processing method using a known signal property strategy determining method;

a group of one or more modes of an adaptive smart antenna spatial processing method using a known training signal strategy determining method; and

a group of one or more modes of a switched beam smart antenna spatial processing method.

69. A wireless remote terminal receiver as recited in claim 68, wherein the set of spatial processing modes includes one or more modes of at least two spatial processing methods.

70. A wireless remote terminal receiver as recited in claim 68, wherein at least one of the groups includes different modes of a spatial processing method that has an associated frequency of determining the spatial processing strategy, and wherein the spatial processing modes in the group have different associated frequencies of determining the strategy, such that selecting from amongst the different modes in the group provides modes that consume different amounts of overall computational power.

71. A wireless remote terminal receiver as recited in claim 68,

wherein the remote terminal unit further comprises:

a plurality of receive paths, one coupled to each antenna to accept the signal from the antenna, and

means to switch at least some of the receive paths between a first operating mode and a second operating mode, the first operating mode consuming more power than the second operating mode,

such that one or more of the spatial processing modes can include operating one or more of the receive paths in the second operating mode, and one or more receive paths at the first operating mode.

72. A wireless remote terminal receiver as recited in claim 71, wherein the first operating mode is on and the second operating mode is off such that none or more of the switchable receive paths are switched off depending on the selected spatial processing mode.

73. A wireless remote terminal receiver as recited in claim 68,

wherein the set of spatial processing modes includes a group of one or more modes of a delay and add processing method,

wherein the plurality of antennas includes a first antenna and one or more additional antennas, and

wherein operating under delay and add processing method includes forming a sum of the signal received at the first antenna and delayed versions of respective signals received at the one or more additional antennas.

74. A wireless remote terminal receiver as recited in claim 73,

wherein the set of spatial processing modes includes at least one additional group of one or more modes of an additional processing method, and

wherein the delay and add processing consumes less power than at least one of the other additional spatial processing mode groups.

75. A wireless remote terminal receiver as recited in claim 69, wherein the set of spatial processing modes includes a plurality of modes of a switched diversity method that periodically selects the best antenna, and wherein at least some of the different switched diversity modes differ by how often the best antenna is selected.

76. A wireless remote terminal receiver as recited in claim 69,

wherein the set of spatial processing modes includes one or more modes of a switched diversity method that periodically selects the best antenna,

wherein the remote terminal unit includes a plurality of receive paths, one coupled to each antenna to accept the signal from the antenna, at least some of the receive paths switchable on or off, and

wherein all receive paths but one are switched off when the wireless remote terminal receiver operates under at least one of the switched diversity modes.

77. A wireless remote terminal receiver as recited in claim 68, wherein the set of spatial processing modes includes a plurality of modes of an adaptive smart antenna spatial processing method that periodically determines a smart antenna processing strategy, and wherein at least some of the different adaptive smart antenna modes differ by how often the smart antenna processing strategy is determined.

78. A wireless remote terminal receiver as recited in claim 68, wherein the means for selecting includes means for the user to manually select the spatial processing mode.

79. A wireless remote terminal receiver as recited in claim 68, wherein the means for selecting includes means for selecting according to signals received at the remote terminal unit from a communicating remote device.

80. A wireless remote terminal receiver as recited in claim 68, wherein the means for selecting includes means for automatically selecting according to one or more selection criteria.

81. A wireless remote terminal receiver as recited in claim 80, wherein the spatial processing mode remains until the end of a communication with a remote device or until communication with the remote device fails.

82. A wireless remote terminal receiver as recited in claim 81, wherein an indication of failure of communication is that the quality of reception falls below a predefined level.

83. A wireless remote terminal receiver as recited in claim 80, wherein the one or more criteria include one or more criteria from a set consisting of one or more protocol-based selection criteria, one or more performance-based selection criteria, and one or more operational-based selection criteria.

84. A wireless remote terminal receiver as recited in claim 80, wherein the one or more criteria include the quality of reception.

85. A wireless remote terminal receiver as recited in claim 84, wherein the quality of reception is one of the received signal strength indication (RSSI), the signal-to-noise (SNR) ratio, the carrier-to-interference ratio (CIR), the bit error rate (BER), the frame error rate (FER), and the spatial correlation between a transmitting remote transmitting device and an interfering remote transmitting device.

86. A wireless remote terminal receiver as recited in claim 80, wherein the one or more criteria include one or more protocol-based criteria including a type of wireless communication system the remote terminal unit operates in.

87. A wireless remote terminal receiver as recited in claim 80, wherein the remote terminal unit and a wireless communication system the remote terminal unit operates in operate according to a multi-state protocol, and wherein one or more criteria include one or more operational-based criteria including the current state of the protocol the remote terminal unit is in.

88. A wireless remote terminal receiver as recited in claim 80, wherein the means for selecting includes means for adaptively selecting the processing mode, including selecting a first spatial processing mode to process received signals for a first time period, selecting a different second spatial processing mode for processing received signals for a second time period, comparing the performance of the first and second modes and thereafter selecting the better performing spatial processing mode.

89. A wireless remote terminal receiver as recited in claim 80, wherein the means for selecting includes means for initially selecting a primary spatial processing and then adaptively selecting the processing mode according to a duty cycle process to compare one or more different spatial processing modes with the primary spatial processing mode at different times.

90. A wireless remote terminal receiver as recited in claim 89, wherein the duty cycle process includes repeating the steps of:

using the primary spatial processing mode to process received signals for a first time period,

selecting a different second spatial processing mode and processing received signals using the second mode for a second time period according to a selected relative length of the first and second time periods, called the duty cycle,

comparing the performance of the primary and second modes; and

selecting the better performing spatial processing mode as the primary mode.

91. A wireless remote terminal receiver as recited in claim 78, wherein the set of spatial processing modes includes one or more modes of at least two spatial processing methods.

92. A wireless remote terminal receiver as recited in claim 91, wherein activating the means for manually selecting selects a spatial processing method and mode that is known to provide better reception.

93. A wireless remote terminal receiver as recited in claim 80, wherein the set of spatial processing modes includes one or more modes of at least two spatial processing methods.

94. A method of processing signals received at one or more antennas of a remote terminal, the remote terminal unit including a plurality of antennas, the method comprising:

providing a plurality of spatial processing modes to process the signals received at the antennas, the plurality of spatial processing modes including one or more modes of a set of one or more spatial processing methods;

selecting a spatial processing mode from the provided plurality; and

processing the signals received at the one or more antennas by the selected spatial processing mode.

95. A method as recited in claim 94,

wherein selecting includes selecting the spatial processing method in the case that more than one spatial processing method is provided, and

wherein processing the received signals includes applying a spatial processing method and a spatial processing mode thereof selected from the plurality of modes.

96. A method as recited in claim 95, wherein the set of spatial processing modes includes at least one of:

a group of one or more modes of a delay and add processing method;

a group of one or more modes of a switched antenna diversity spatial processing method;

a group of one or more modes of an adaptive smart antenna spatial processing method using a maximum ratio combining strategy determining method;

a group of one or more modes of an adaptive smart antenna spatial processing method using a known signal property strategy determining method;

a group of one or more modes of an adaptive smart antenna spatial processing method using a known training signal strategy determining method; and

a group of one or more modes of a switched beam smart antenna spatial processing method.

97. A method as recited in claim 96, wherein the set of spatial processing modes includes one or more modes of at least two spatial processing methods.

98. A method as recited in claim 96, wherein at least one of the groups includes different modes of a spatial processing method that has an associated frequency of determining the spatial processing strategy, and wherein the spatial processing modes in the group have different associated frequencies of determining the strategy, such that selecting from amongst the different modes in the group provides modes that consume different amounts of overall computational power.

99. A method as recited in claim 96,

wherein the remote terminal unit further includes a plurality of receive paths, one coupled to each antenna to accept the signal from the antenna, at least some of the receive paths switchable between a first operating mode and a second operating mode, the first operating mode consuming more power than the second operating mode, and

wherein some of the receive paths operate at different operating modes for at least some of the spatial processing modes, such that some of the spatial processing modes differ in power consumption of the remote terminal unit when operating under the spatial processing mode.

100. A method as recited in claim 99, wherein the first operating mode is on and the second operating mode is off such that none or more of the switchable receive paths are switched off depending on the selected spatial processing mode.

101. A method as recited in claim 96,

wherein the set of spatial processing modes includes a group of one or more modes of a delay and add processing method,

wherein the plurality of antennas includes a first antenna and one or more additional antennas, and

wherein operating under delay and add processing method includes forming a sum of the signal received at the first antenna and delayed versions of respective signals received at the one or more additional antennas.

102. A method as recited in claim 101,

wherein the set of spatial processing modes includes at least one additional group of one or more modes of an additional processing method, and

wherein the delay and add processing consumes less power than at least one of the other additional spatial processing mode groups.

103. A method as recited in claim 97, wherein the set of spatial processing modes includes a plurality of modes of a switched diversity method that periodically selects the best antenna, and wherein at least some of the different switched diversity modes differ by how often the best antenna is selected.

104. A method as recited in claim 97,

wherein the set of spatial processing modes includes one or more modes of a switched diversity method that periodically selects the best antenna,

wherein the remote terminal unit includes a plurality of receive paths, one coupled to each antenna to accept the signal from the antenna, at least some of the receive paths switchable on or off, and

wherein all receive paths but one are switched off when the wireless remote terminal receiver operates under at least one of the switched diversity modes.

105. A method as recited in claim 96, wherein the set of spatial processing modes includes a plurality of modes of an adaptive smart antenna spatial processing method that periodically determines a smart antenna processing strategy, and wherein at least some of the different adaptive smart antenna modes differ by how often the smart antenna processing strategy is determined.

106. A method as recited in claim 96, wherein the remote terminal unit includes a user interface with a manual mode selector to manually select the spatial processing mode, and wherein the selecting includes a user manually selecting using the manual mode selector.

107. A method as recited in claim 96, wherein the selecting is according to signals received at the remote terminal unit from a communicating remote device.

108. A method as recited in claim 96, wherein the selecting is automatic according to one or more selection criteria.

109. A method as recited in claim 108, wherein the spatial processing mode remains until the end of a communication with a remote device or until communication with the remote device fails.

110. A method as recited in claim 109, wherein an indication of failure of communication is that the quality of reception falls below a predefined level.

111. A method as recited in claim 108, wherein the one or more criteria include one or more criteria from a set consisting of one or more protocol-based selection criteria, one or more performance-based selection criteria, and one or more operational-based selection criteria.

112. A method as recited in claim 108, wherein the one or more criteria include the quality of reception.

113. A method as recited in claim 112, wherein the quality of reception is one of the received signal strength indication (RSSI), the signal-to-noise (SNR) ratio, the carrier-to-interference ratio (CIR), the bit error rate (BER), the frame error rate (FER), and the spatial correlation between a transmitting remote transmitting device and an interfering remote transmitting device.

114. A method as recited in claim 108, wherein the one or more criteria include one or more protocol-based criteria including a type of wireless communication system the remote terminal unit operates in.

115. A method as recited in claim 108, wherein the remote terminal unit and a wireless communication system the remote terminal unit operates in operate according to a multi-state protocol, and wherein one or more criteria include one or more operational-based criteria including the current state of the protocol the remote terminal unit is in.

116. A method as recited in claim 108,

wherein the remote terminal unit includes a memory coupled storing a table, each entry containing a references to one of the spatial processing modes and indexed by a function of the one or more criteria, and

wherein the automatic selecting includes indexing the table to select the spatial processing mode.

117. A method as recited in claim 108,

wherein the one or more criteria include at least two criteria,

wherein the remote terminal includes a memory storing a set of tables, each entry containing a references to one of the tables or to one of the spatial processing modes and indexed by a function of the one of the criteria, and

wherein the automatic selecting includes indexing the set of table to select the spatial processing mode.

118. A method as recited in claim 108, wherein the selecting adaptively selects the processing mode including selecting a first spatial processing mode to process received signals for a first time period, selecting a different second spatial processing mode for processing received signals for a second time period, comparing the performance of the first and second modes and thereafter selecting the better performing spatial processing mode.

119. A method as recited in claim 118, wherein the selecting includes selecting the first spatial processing mode randomly from the available spatial processing modes.

120. A method as recited in claim 118, wherein the selecting includes selecting the first spatial processing mode according to a first criterion.

121. A method as recited in claim 120, wherein the first criterion is a performance criterion.

122. A method as recited in claim 120, wherein the first criterion is based at least on an operational state of the remote terminal unit.

123. A method as recited in claim 118, wherein the relative lengths of the first and second time periods, called the duty cycle, is pre-defined.

124. A method as recited in claim 108, wherein the selecting includes initially selecting a primary spatial processing and then adaptively selecting the processing mode according to a duty cycle process to compare one or more different spatial processing modes with the primary spatial processing mode at different times.

125. A method as recited in claim 124, wherein the duty cycle process includes repeating the steps of:

using the primary spatial processing mode to process received signals for a first time period,

selecting a different second spatial processing mode and processing received signals using the second mode for a second time period according to a selected relative length of the first and second time periods, called the duty cycle,

comparing the performance of the primary and second modes; and

selecting the better performing spatial processing mode as the primary mode.

126. A method as recited in claim 125, wherein the selected duty cycle is pre-defined.

127. A method as recited in claim 125, wherein the selected duty cycle is selected according to a duty cycle selection criterion.

128. A method as recited in claim 127, wherein the selected duty cycle is selected by a remote device in communication with the remote terminal.

129. A method as recited in claim 125, wherein the selecting includes selecting the first spatial processing mode according to a first criterion.

130. A method as recited in claim 125, wherein the selecting includes selecting the first spatial processing mode randomly from among available spatial processing modes.

131. A method as recited in claim 129, wherein the first criterion is a performance criterion.

132. A method as recited in claim 129, wherein the first criterion is based at least on an operational state of the remote terminal unit.

133. A method as recited in claim 129, wherein the selected duty cycle is selected according to a duty cycle selection criterion.

134. A method as recited in claim 129, wherein the duty cycle selection criterion is initially the same as the first selection criterion, and thereafter is the relative performance in the first and second time periods, such that the duty cycle is varied according to the relative performance.

135. A method as recited in claim 106, wherein the set of spatial processing modes includes one or more modes of at least two spatial processing methods.

136. A method as recited in claim 135, wherein the manually selecting selects a spatial processing method and mode that is known to provide better reception.

137. A method as recited in claim 106, wherein at least one of the groups includes different modes of a spatial processing method that has an associated frequency of determining the spatial processing strategy, and wherein the spatial processing modes in the group have different associated frequencies of determining the strategy, such that selecting from amongst the different modes in the group provides modes that consume different amounts of overall computational power.

138. A method as recited in claim 106,

wherein the remote terminal unit further includes a plurality of receive paths, one coupled to each antenna to accept the signal from the antenna, at least some of the receive paths switchable between a first operating mode and a second operating mode, the first operating mode consuming more power than the second operating mode, and

wherein some of the receive paths operate at different operating modes for at least some of the spatial processing modes, such that some of the spatial processing modes differ in power consumption of the remote terminal unit when operating under the spatial processing mode.

139. A method as recited in claim 138, wherein the first operating mode is on and the second operating mode is off such that none or more of the switchable receive paths are switched off depending on the selected spatial processing mode.

140. A method as recited in claim 108, wherein the set of spatial processing modes includes one or more modes of at least two spatial processing methods.

141. A method as recited in claim 108, wherein at least one of the groups includes different modes of a spatial processing method that has an associated frequency of determining the spatial processing strategy, and wherein the spatial processing modes in the group have different associated frequencies of determining the strategy, such that selecting from amongst the different modes in the group provides modes that consume different amounts of overall computational power.

142. A method as recited in claim 108,

wherein the remote terminal unit further includes a plurality of receive paths, one coupled to each antenna to accept the signal from the antenna, at least some of the receive paths switchable between a first operating mode and a second operating mode, the first operating mode consuming more power than the second operating mode, and

wherein some of the receive paths operate at different operating modes for at least some of the spatial processing modes, such that some of the spatial processing modes differ in power consumption of the remote terminal unit when operating under the spatial processing mode.

143. A method as recited in claim 142, wherein the first operating mode is on and the second operating mode is off such that none or more of the switchable receive paths are switched off depending on the selected spatial processing mode.