Distributed antenna system using time division duplexing scheme
A communication system includes a master host unit that communicates wireless spectrum with a service provider interface using analog spectrum. Master host unit communicates digitized spectrum in N-bit words over a digital communication link. Master host unit converts between analog spectrum and N-bit words of digitized spectrum. Communication system includes hybrid expansion unit coupled to master host unit by digital communication link. Hybrid expansion unit communicates N-bit words of digitized spectrum with master host unit across digital communication link. Hybrid expansion unit converts between N-bit words of digitized spectrum and analog spectrum. Hybrid expansion unit communicates analog spectrum across analog communication link to analog remote antenna unit. Analog remote antenna unit communicates wireless signals using first antenna. Communication system further includes a switch in a data path between service provider interface and antenna. The switch selects between transmit path and receive path in response to switching control signal.
1. A communication system, comprising:
a first master host unit configured to communicate first wireless spectrum with a first service provider interface using a first set of bands of analog spectrum;
a plurality of digital communication links coupled to the first master host unit, wherein the first master host unit is further configured to communicate a first digitized spectrum in first N-bit words over a first digital communication link of the plurality of digital communication links;
wherein the first master host unit is further configured to convert between the first set of bands of analog spectrum and the first N-bit words of digitized spectrum;
a first hybrid expansion unit communicatively coupled to the first master host unit by the first digital communication link of the plurality of digital communication links and configured to communicate the first N-bit words of digitized spectrum with the first master host unit across the first digital communication link, the first hybrid expansion unit further configured to convert between the first N-bit words of digitized spectrum and a second set of bands of analog spectrum;
a first analog communication link coupled to the first hybrid expansion unit, wherein the first hybrid expansion unit is further configured to communicate the second set of bands of analog spectrum across the first analog communication link;
a first analog remote antenna unit communicatively coupled to the first hybrid expansion unit by the first analog communication link and configured to communicate the second set of bands of analog spectrum across the first analog communication link, the first analog remote antenna unit further configured to communicate first wireless signals over a first air interface using a first antenna;
a first switch positioned in a first data path between the first service provider interface and the first antenna, wherein the first switch is selected between a transmit path and a receive path in response to a first switching control signal; and
wherein at least one of:
at least one of the first master host unit, the first hybrid expansion unit, and the first analog remote antenna unit is further configured to receive the switching control signal from an external source external to the communication system; and
at least one of the first master host unit, the first hybrid expansion unit, and the first analog remote antenna unit further includes a first switch signal controller that generates the first switching control signal.
2. The system of claim 1 , wherein the first switch is included in at least one of the first master host unit, the first hybrid expansion unit, and the first analog remote antenna unit.
3. The system of claim 1 , wherein the first analog remote antenna unit transmits the first wireless signals over the first air interface using the first antenna when the first switch is selected to the first transmit path.
4. The system of claim 1 , wherein the first analog remote antenna unit receives the first wireless signals over the first air interface using the first antenna when the first switch is selected to the first receive path.
5. The system of claim 1 , wherein the first switching control signal is a one bit binary value.
6. The system of claim 1 , wherein at least one of the first master host unit, the first hybrid expansion unit, and the first analog remote antenna unit further include a first switch signal controller that receives the first switching control signal from the first service provider interface.
7. The system of claim 1 , wherein at least one of the first master host unit, the first hybrid expansion unit, and the first analog remote antenna unit further include a first switch signal controller that derives the first switching control signal from a frame clock signal received from the first service provider interface.
8. The system of claim 1 , wherein at least one of the first master host unit, the first hybrid expansion unit, and the first analog remote antenna unit further include a first switch signal controller that generates the first switching control signal.
9. The system of claim 8 , wherein the first switch signal controller generates the first switching control signal by comparing a threshold power level with a downlink power level of downlink signals in the first data path.
10. The system of claim 8 , wherein the first switch signal controller generates the first switching control signal by correlating detected downlink power of downlink signals in the first data path with a downlink power reference.
11. The system of claim 8 , wherein the first switch signal controller generates the first switching control signal by comparing a threshold power level with an uplink power level of uplink signals in the first data path.
12. The system of claim 8 , wherein the first switch signal controller generates the first switching control signal by correlating detected uplink power of uplink signals in the first data path with an uplink power reference.
13. The system of claim 8 , wherein the first switch signal controller further:
demodulates a first signal in the first wireless spectrum; and
determines from the demodulated first signal when the first switching control signal should indicate transmitting or receiving.
14. The system of claim 1 , wherein the master host unit includes a first switch signal controller that generates the first switching control signal;
wherein the first master host unit is further configured to communicate the first switching control signal to the first hybrid expansion unit across the first digital communication link; and
wherein the first hybrid expansion unit is further configured to communicate the first switching control signal to the first analog remote antenna unit across the first analog communication link.
15. The system of claim 14 , wherein the first switching control signal is communicated across the first digital communication link in a control word of a frame of data communicated across the first digital communication link.
16. The system of claim 14 , wherein the first switching control signal is communicated across the first digital communication link in a sampled data word of a frame of data communicated across the first digital communication link.
17. The system of claim 16 , wherein the first switching control signal is communicated across the first digital communication link using at least one embedded control bit in the sampled data word.
18. The system of claim 14 , wherein the first switching control signal is communicated across the first digital communication link using at least one of an error detection code and a correction code.
19. The system of claim 14 , wherein the first switching control signal is communicated across the first digital communication link using an odd number of bits greater than two; and
wherein the first hybrid expansion unit is further configured to utilize a majority rule scheme to validate the first switching control signal.
20. The system of claim 1 , wherein the first hybrid expansion unit includes a first switch signal controller that generates the first switching control signal; and
wherein the first hybrid expansion unit is further configured to communicate the first switching control signal to the first analog remote antenna unit across the first analog communication link.
21. The system of claim 1 , wherein the first analog remote antenna unit includes a first switch signal controller that generates the first switching control signal.
22. The system of claim 21 , wherein the master analog remote antenna unit is the first analog remote antenna unit.
23. The system of claim 1 , wherein the first wireless signals are the first set of bands of analog spectrum.
24. The system of claim 1 , wherein the first analog remote antenna unit is part of a first analog remote antenna cluster that includes:
a master analog remote antenna unit configured to communicate the second set of bands of analog spectrum with the first hybrid expansion unit across the first analog communication link; and
wherein the master analog remote antenna unit distributes the second set of bands of analog spectrum to the first analog remote antenna unit.
25. The system of claim 1 , further comprising:
a first digital remote antenna unit communicatively coupled to the first master host unit by a second digital communication link of the plurality of digital communication links and configured to communicate second N-bit words of digitized spectrum with the first master host unit across the second digital communication link, the first digital remote antenna unit is further configured to communicate second wireless signals over a second air interface using a second antenna;
wherein the first digital remote antenna unit includes a second switch that is selected between a transmitter and a receiver in response to a second switching control signal; and
wherein the first master host unit is further configured to convert between the first set of bands of analog spectrum and the second N-bit words of digitized spectrum.
26. The system of claim 25 , wherein a first downlink portion of the first wireless signals is a second downlink portion of the second wireless signals.
27. The system of claim 25 , wherein the first digital remote antenna unit transmits the second wireless signals over the second air interface using the second antenna when the second switch is selected to the transmitter.
28. The system of claim 25 , wherein the first digital remote antenna unit receives the second wireless signals over the second air interface using the second antenna when the second switch is selected to the receiver.
29. The system of claim 25 , wherein the second switching control signal is the first switching control signal.
30. The system of claim 25 , wherein the master host unit includes a second switch signal controller that generates the second switching control signal;
wherein the first master host unit is further configured to communicate the second switching control signal to the first digital remote antenna unit across the second digital communication link.
31. The system of claim 30 , wherein the second switching control signal is the first switching control signal.
32. The system of claim 25 , wherein the first digital remote antenna unit includes a second switch signal controller that generates the second switching control signal.
33. The system of claim 25 , wherein first N-bit words of digitized spectrum is the second N-bit words of digitized spectrum in the downstream.
34. The system of claim 25 , wherein the second wireless signals are derived from the first set of bands of analog spectrum.
35. The system of claim 1 , wherein the first master host unit is further configured to communicate third wireless spectrum with a second service provider interface using a third set of bands of analog spectrum;
wherein the first master host unit is further configured to communicate a second digitized spectrum in second N-bit words over a second digital communication link of the plurality of digital communication links;
wherein the first master host unit is further configured to convert between the third set of bands of analog spectrum and the second N-bit words of digitized spectrum;
a second hybrid expansion unit communicatively coupled to the first master host unit by the second digital communication link of the plurality of digital communication links and configured to communicate the second N-bit words of digitized spectrum with the first master host unit across the second digital communication link, the second hybrid expansion unit further configured to convert between the second N-bit words of digitized spectrum and a fourth set of bands of analog spectrum;
a second analog communication link coupled to the second hybrid expansion unit, wherein the second hybrid expansion unit is further configured to communicate the fourth set of bands of analog spectrum across the second analog communication link;
a second analog remote antenna unit communicatively coupled to the second hybrid expansion unit by the second analog communication link and configured to communicate the fourth set of bands of analog spectrum across the second analog communication link, the second analog remote antenna unit further configured to communicate second wireless signals over a second air interface using a second antenna; and
wherein the second analog remote antenna unit includes a second switch that is selected between a transmitter and a receiver in response to a second switching control signal.
36. The system of claim 35 , wherein the first digital communication link is the second digital communication link.
37. The system of claim 35 , wherein the first hybrid expansion unit is the second hybrid expansion unit;
wherein the first analog remote antenna unit and the second analog remote antenna unit are each part of a first analog remote antenna cluster that includes:
a master analog remote antenna unit configured to communicate the second set of bands of analog spectrum with the first hybrid expansion unit across the first analog communication link and the fourth set of bands of analog spectrum with the first hybrid expansion link across the second analog communication link;
wherein the master analog remote antenna unit distributes the second set of bands of analog spectrum to the first analog remote antenna unit; and
wherein the master analog remote antenna unit distributes the fourth set of bands of analog spectrum to the second analog remote antenna unit.
38. The system of claim 37 , wherein the first analog communication link is the second analog communication link.
39. The system of claim 37 , wherein the master analog remote antenna unit is the first analog remote antenna unit.
40. A method comprising:
converting first wireless spectrum between a first set of bands of analog spectrum and first N-bit words of digitized spectrum using a first master host unit;
transporting the first N-bit words of digitized spectrum on a first digital medium between the first master host unit and a first hybrid expansion unit;
converting first wireless spectrum between the first N-bit words of digitized spectrum and a second set of bands of analog spectrum at the first hybrid expansion unit;
transporting the second set of bands of analog spectrum on a first analog medium between the first hybrid expansion unit and a first analog remote antenna unit;
switching the first analog remote antenna unit between a transmit mode and a receive mode based on a first switching control signal;
when the first analog remote unit is in the transmit mode, transmitting first wireless spectrum at the first analog remote antenna unit using a first antenna;
when the first analog remote antenna unit is in the receive mode, receiving a second wireless spectrum at the first analog remote antenna unit using a second antenna; and
at least one of:
receiving the first switching control signal from an external source using at least one of the first master host unit, the first hybrid expansion unit, and the first analog remote antenna unit; and
generating the first switching control signal using at least one of the first master host unit, the first hybrid expansion unit, and the first analog remote antenna unit.
41. The method of claim 40 , wherein the first wireless spectrum is the second wireless spectrum.
42. The method of claim 40 , wherein the first antenna is the second antenna.
43. The method of claim 40 , wherein the first switching control signal is a one bit binary value.
44. The method of claim 40 , further comprising generating the first switching control signal by at least one of:
comparing a first threshold power level with a power level of a downlink communication path in the first wireless spectrum; and
comparing a second threshold power level with a power level of an uplink communication path in the second wireless spectrum.
45. The method of claim 40 , further comprising generating the first switching control signal by at least one of:
correlating a downlink power reference with a detected downlink power of a downlink communication path in the first wireless spectrum; and
correlating an uplink power level with a power level of an uplink communication path in the second wireless spectrum.
46. The method of claim 40 , further comprising:
demodulating a signal in the first wireless spectrum;
determining when the first switching control signal should indicate transmitting or receiving based on the demodulated signal; and
generating the first switching control signal according to the determination of when the first switching control signal should indicate transmitting or receiving.
47. The method of claim 40 , further comprising:
receiving the first switching control signal from a first service provider interface using the first master host unit.
48. The method of claim 40 , further comprising:
generating the first switching control signal using the first master host unit;
communicating the first switching control signal to the first hybrid expansion unit across the first digital communication link;
converting the first switching control signal from digital to analog using the first hybrid expansion unit; and
communicating the first switching control signal to the first analog remote antenna unit across the first analog communication link.
49. The method of claim 48 , wherein communicating the first switching control signal to the first hybrid expansion unit across the first digital communication link comprises communicating the first switching control signal in a control word of a frame of data communicated across the first digital communication link.
50. The method of claim 48 , wherein communicating the first switching control signal to the first hybrid expansion unit across the first digital communication link comprises communicating the first switching control signal in a sampled data word of a frame of data communicated across the first digital communication link.
51. The method of claim 50 , wherein the first switching control signal is communicated across the first digital communication link using at least one embedded control bit in the sampled data word.
52. The method of claim 48 , wherein communicating the first switching control signal to the first hybrid expansion unit across the first digital communication link comprises communicating the first switching control signal across the first digital communication link using a code.
53. The method of claim 48 , wherein communicating the first switching control signal to the first hybrid expansion unit across the first digital communication link comprises communicating the first switching control signal using an odd number of bits greater than two; and
validating the first switching control signal received at the hybrid expansion unit using a majority rule scheme on the odd number of bits greater than two.
54. The method of claim 40 , further comprising:
generating the first switching control signal at the first hybrid expansion unit; and
communicating the first switching control signal to the first analog remote antenna unit across the first analog communication link.
55. The method of claim 40 , further comprising:
generating the first switching control signal at the first analog remote antenna unit.
56. The method of claim 40 , wherein the first wireless signals are derived from the first set of bands of analog spectrum.
57. The method of claim 40 , wherein the second set of bands of analog spectrum comprise intermediate frequencies.
58. The method of claim 40 , wherein the first wireless spectrum is communicated as a third band of analog spectrum.
59. The method of claim 58 , wherein the third band of analog spectrum is the first band of analog spectrum.
60. The method of claim 40 , further comprising:
converting third wireless spectrum between fourth set of bands of analog spectrum and second N-bit words of digitized spectrum at the first master host unit;
transporting the second N-bit words of digitized spectrum on a second digital medium between the first master host unit and a first digital remote antenna unit;
switching the first digital remote antenna unit between the transmit mode and the receive mode based on a second switching control signal;
when the first digital remote antenna unit is in the transmit mode, transmitting third wireless spectrum at the first digital remote antenna unit using a third antenna; and
when the first digital remote antenna unit is in the receive mode, receiving fourth wireless spectrum at the first digital remote antenna unit using a fourth antenna.
61. The method of claim 60 , wherein the first wireless spectrum is the third wireless spectrum.
62. A hybrid expansion unit comprising:
at least one digital communication interface configured to communicate first and second sets of N-bit words of digitized spectrum with an upstream device;
at least one analog communication interface configured to communicate first and second sets of bands of analog spectrum with a downstream device;
wherein the hybrid expansion unit is configured to convert between the first set of N-bit words of digitized spectrum and the first set of bands of analog spectrum;
wherein the hybrid expansion unit is further configured to communicate a switching control signal to the downstream device using the at least one analog communication interface, wherein the switching control signal indicates when a switch positioned in a first data path between the hybrid expansion unit and at least one downstream antenna should be selected between a transmitter and a receiver; and
wherein the hybrid expansion unit is further configured to at least one of:
generate the switching control signal using a switch signal controller within the hybrid expansion unit; and
receive a digital switching control signal from another device and convert the digital switching control signal to the switching control signal using a switch signal converter within the hybrid expansion unit.
63. The hybrid expansion unit of claim 62 , further comprising:
wherein the hybrid expansion unit is further configured to receive the switching control signal from the upstream device through the at least one digital communication interface.
64. The hybrid expansion unit of claim 62 , wherein the hybrid expansion unit is configured to receive the switching control signal from the upstream device in a control word of a frame of data communicated from the upstream device through the at least one digital communication interface.
65. The hybrid expansion unit of claim 62 , wherein the hybrid expansion unit is configured to receive the switching control signal from the upstream device through the at least one digital communication interface in a sampled data word of a frame of data communicated across the first digital communication link.
66. The hybrid expansion unit of claim 62 , wherein the hybrid expansion unit is configured to receive the switching control signal from the upstream device through the at least one digital communication interface using at least one embedded control bit in the sampled data word.
67. The hybrid expansion unit of claim 62 , wherein the hybrid expansion unit is configured to receive the switching control signal from the upstream device through the at least one digital communication interface using a multi-bit code.
68. The hybrid expansion unit of claim 62 , wherein the hybrid expansion unit is configured to receive the switching control signal from the upstream device through the at least one digital communication interface using an odd number of bits greater than two; and
wherein the hybrid expansion unit is further configured to utilize a majority rule scheme to validate the first switching control signal.
69. The hybrid expansion unit of claim 62 , further comprising a switch signal controller configured to generate the switching control signal based on a comparison between a threshold power level and at least one of:
a first power level of a downlink communication path in the digitized spectrum; and
a second power level of an uplink communication path in the digitized spectrum.
70. A method comprising:
communicating a first set of N-bit words of digitized spectrum between a hybrid expansion unit and an upstream device;
communicating a first set of bands of analog spectrum between the hybrid expansion unit and a downstream device;
converting between the first set of N-bit words of digitized spectrum and the first set of bands of analog spectrum at the hybrid expansion unit;
communicating a switching control signal to the downstream device from the hybrid expansion unit, wherein the switching control signal indicates when a switch positioned in a first data path between the hybrid expansion unit and at least one downstream antenna should be selected between a transmit path and a receive path; and
at least one of:
receiving the switching control signal from another device; and
generating the switching control signal at the hybrid expansion unit.
71. The method of claim 70 , further comprising:
receiving the switching control signal from the upstream device.
72. The method of claim 70 , further comprising generating the switching control signal based on a comparison between a threshold power level and at least one of:
a first power level of a downlink communication path in the digitized spectrum; and
a second power level of an uplink communication path in the digitized spectrum.