Multiple-antenna system for cellular communication and broadcasting

• US 8,116,822 B1
• Filed: 10/18/2011
• Issued: 02/14/2012
• Est. Priority Date: 11/14/2005
• Status: Active Grant

• Current Assignee: Neo Wireless LLC (f/k/a CFIP NCF LLC) (SoftBank Group Corp.)
• Original Assignee: Neocific Incorporated
• Inventors: Lo, Titus, Li, Xiaodong
• Primary Examiner(s): Nguyen, Duc
• Assistant Examiner(s): Jain, Ankur
• Application Number:
  US13/276,240
• Publication Number:
  US 20120034952A1
• Time in Patent Office: 119 Days
• Field of Search: 455/562.1
• US Class Current: 455/562.1
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04L 27/2605 Symbol extensions, e.g. Zero Tail, Unique Word [UW]
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 56/0005 synchronizing of arrival of multiple uplinks
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A multiple-antenna system for use in cellular communication and broadcasting. The multiple-antenna transmission system can be controlled, adjusted, configured, or reconfigured to produce desirable radiation beam patterns suitable for different types of applications. A signal distribution network may be provided in the multiple-antenna system. The signal distribution network is embedded in a transmitter and controls the distribution of signals to one or more antennas in accordance with application requirements. Various antenna radiation patterns suitable for different applications can be generated by reconfiguring the connections and gain settings in the signal distribution network. For example, narrow beams may be generated for use in unicast applications, whereas sector beams may be generated for use in broadcast applications. Certain techniques may be employed to manage the transition from one type of transmission mode to another type of transmission mode.

Claims

1. A multi-carrier antenna system for cellular communication and broadcasting in a plurality of transmission modes within a geographic area divided into a plurality of cells, the multi-carrier antenna system comprising:

a plurality of antennas, wherein each of the antennas is capable of generating a beam pattern that may be adjusted in azimuth and elevation for purposes of transmitting signals to mobile devices;

a signal distribution network coupled to the plurality of antennas, the signal distribution network enabling a plurality of input signals to be routed to one or more of the plurality of antennas; and

a controller coupled to the signal distribution network and the plurality of antennas, the controller enabling the multi-carrier antenna system to be switched between a first mode of operation wherein at least one of the plurality of antennas has a first beam pattern with a first azimuth pattern and a first elevation pattern, and a second mode of operation wherein the at least one of the plurality of antennas has a second beam pattern with a second azimuth pattern and a second elevation pattern;

wherein a transition period is inserted between transmissions to mobile devices to provide sufficient time to switch from the first mode of operation to the second mode of operation;

wherein the switch from the first mode of operation to the second mode of operation takes place between OFDM symbols in the transmissions so that at least a portion of a cyclic prefix or a cyclic postfix can be used for the transition period; and

wherein the first beam pattern is different than the second beam pattern in either an azimuth pattern or an elevation pattern.

2. The multi-carrier antenna system of claim 1, wherein the first mode of operation is selected from the group comprising a unicast, a cell-specific broadcast, or a multi-cell broadcast.

3. The multi-carrier antenna system of claim 1, wherein the second mode of operation is selected from the group comprising a unicast, a cell-specific broadcast, or a multi-cell broadcast.

4. The multi-carrier antenna system of claim 1, wherein the signal distribution network further enables the amplification of the input signal to be controlled.

5. The multi-carrier antenna system of claim 4, wherein the signal distribution network comprises:

a plurality of amplifiers, each of the plurality of amplifiers coupled to a line carrying one of the plurality of input signals;

a plurality of splitters, each of the plurality of splitters receiving an amplified signal from one of the plurality of variable-gain amplifiers and splitting the amplified signal into a plurality of split signals;

a plurality of switches associated with each of the plurality of splitters, each of the plurality of switches receiving a split signal from the corresponding splitter and generating a switched signal; and

a plurality of combiners, each of the combiners receiving a switched signal from a switch that is associated with each of the plurality of splitters, wherein the plurality of switches may be turned on or off in accordance with switch control signals to control the routing of the plurality of input signals to the combiners.

6. The multi-carrier antenna system of claim 5, wherein the gain levels of the plurality of amplifiers may be varied in accordance with gain control signals.

7. The multi-carrier antenna system of claim 1, wherein at least one of the plurality of antennas is a sector-antenna.

8. The multi-carrier antenna system of claim 1, wherein at least one of the plurality of antennas is an omni-directional antenna.

9. The multi-carrier antenna system of claim 1, wherein at least one of the plurality of antennas comprises:

a plurality of antenna elements that are controllable to create an elevation pattern; and

at least one beamformer that is coupled to the plurality of antenna elements, and is controllable to create the azimuth pattern, wherein the azimuth pattern is created independently of the elevation pattern.

10. The multi-carrier antenna system of claim 9, wherein the plurality of antenna elements are two-dimensional antenna elements.

11. The multi-carrier antenna system of claim 9, wherein the plurality of antenna elements are three-dimensional antenna elements.

12. The multi-carrier antenna system of claim 9, wherein the azimuth pattern is created by weighting subcarriers in the frequency domain within the beamformers.

13. The multi-carrier antenna system of claim 9, wherein each of the plurality of antenna elements comprises:

a plurality of radiation elements; and

a plurality of electronic circuits interspersed between the plurality of radiation elements, wherein an elevation beam pattern is created by activating at least some of the plurality of electronic circuits between the plurality of radiation elements.

14. The multi-carrier antenna system of claim 9, wherein an azimuth pattern and an elevation pattern is associated with each mode of operation.

15. The multi-carrier antenna system of claim 14, wherein a mode of operation is a unicast mode, and the azimuth pattern associated with the unicast mode is a beam pattern that is narrower than the width of a sector in which unicast transmissions are being made.

16. The multi-carrier antenna system of claim 14, wherein a mode of operation is a cell-specific broadcast mode, and the azimuth pattern associated with the cell-specific broadcast mode is a beam pattern that is the same width as the width of a sector in which the cell-specific broadcast transmissions are being made.

17. The multi-carrier antenna system of claim 14, wherein a mode of operation is a multi-cell broadcast mode, and the azimuth pattern associated with the multi-cell broadcast mode is a beam pattern that is greater than the size of a sector in which the multi-cell broadcasts are being made.

18. The multi-carrier antenna system of claim 1, further comprising a plurality of signal distribution networks coupled to the plurality of antennas.

19. The multi-carrier antenna system of claim 1, wherein a first configuration index is associated with a beam pattern associated with the first mode of operation and a second configuration index is associated the second mode of operation and wherein the controller switches between the first mode of operation and the second mode of operation after receiving a command containing the first or second configuration index.

20. The multi-carrier antenna system of claim 1, the controller further enabling the multi-carrier antenna system to be switched between a plurality of modes of operation.

21. A method of switching between at least two modes of operation in a multi-carrier antenna system for cellular communication and broadcasting, the method comprising:

identifying a first beam pattern suitable for a first application using a first group of OFDM symbols, the first beam pattern having an azimuth pattern and an elevation pattern;

configuring a signal distribution network to route and amplify first signals from one or more baseband processors to a plurality of antennas for transmission to a cell within a cellular communication system, wherein the routing and amplification is selected in order to generate the first beam pattern suitable for the first application;

identifying a second beam pattern suitable for a second application using a second group of OFDM symbols, the second beam pattern differing from the first beam pattern in either an azimuth pattern or an elevation pattern; and

re-configuring the signal distribution network to route and amplify second signals from the one or more baseband processors to the plurality of antennas for transmission to the cell within the cellular communication system, wherein the routing and amplification is selected in order to generate the second beam pattern suitable for the second application;

wherein a transition period is inserted between transmissions to mobile devices to provide sufficient time for re-configuring the signal distribution network;

wherein re-configuring the signal distribution network takes place between OFDM symbols in the transmissions so that at least a portion of a cyclic prefix or a cyclic postfix can be used for the transition period.

22. The method of claim 21, wherein the first beam pattern and second beam pattern are selected from the group comprising a unicast, a cell-specific broadcast, or a multi-cell broadcast.

23. The method of claim 21, wherein the routing in the signal distribution network is configured by turning on or off switches in the signal distribution network.

24. The method of claim 21, wherein a configuration index is associated with each beam pattern, and wherein the signal distribution network is configured using a control instruction containing a configuration index associated with a desired beam pattern.

25. The method of claim 21, further comprising inserting a transition period between the transmission of the first signals and the second signals in order to allow the multi-carrier antenna system to be re-configured.