Multiple-antenna system for cellular communication and broadcasting

• US 8,041,395 B2
• Filed: 11/14/2006
• Issued: 10/18/2011
• Est. Priority Date: 11/14/2005
• Status: Active Grant

• Current Assignee: Neo Wireless LLC (f/k/a CFIP NCF LLC) (FIG LLC (d/b/a Fortress Investment Group LLC))
• Original Assignee: Neocific Incorporated
• Inventors: Lo, Titus, Li, Xiaodong
• Primary Examiner(s): Nguyen; Duc
• Assistant Examiner(s): Jain; Ankur
• Application Number:
  US11/908,262
• Publication Number:
  US 20090280866A1
• Time in Patent Office: 1,799 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 base station system for cellular communication and broadcasting in a plurality of transmission modes within a geographic area divided into a plurality of cells, the base station system comprising:

a plurality of antennas capable of generating beam patterns adjustable in azimuth, elevation, or both 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 base station system to be switched between a first mode of operation used for a first application wherein at least one of the plurality of antennas has a beam pattern with a first azimuth pattern and a first elevation pattern, and a second mode of operation used for a second application wherein the at least one of the plurality of antennas has a beam pattern with a second azimuth pattern and a second elevation pattern, wherein

the first mode of operation used for the first application is associated with a first group of orthogonal frequency division multiplexing (OFDM) symbols to facilitate transmission to mobile devices within a cell;

wherein the first group of OFDM symbols is transmitted via an antenna by turning on one of multiple switches;

the second mode of operation used for the second application is associated with a second group of OFDM symbols to facilitate transmission to mobile devices in multiple cells over a single frequency network;

wherein the second group of OFDM symbols is transmitted via multiple antennas by turning on multiple switches;

the second azimuth pattern is wider than the first azimuth pattern, the second elevation pattern is more extended than the first elevation pattern, or the second azimuth pattern is wider than the first azimuth pattern and the second elevation pattern is more extended than the first elevation pattern; and

the mode switching takes place during a cyclic prefix or a cyclic postfix between OFDM symbols.

2. The base station system of claim 1, wherein the first application is a data unicasting application.

3. The base station system of claim 1, wherein the second application is a broadcasting application.

4. The base station system of claim 1, wherein the signal distribution network further enables the amplification of an input signal to be controlled.

5. The base station 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 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 base station system of claim 5, wherein the gain levels of the plurality of amplifiers may be varied in accordance with gain control signals.

7. The base station system of claim 5, wherein the signal distribution network enables different configurations for signal unicasting and broadcasting over multiple frequency channels by turning on or off a plurality of switches associated with the splitters.

8. The base station system of claim 7, wherein the switches in the signal distribution network are turned on or off during a cyclic prefix or a cyclic postfix of an OFDM symbol.

9. The base station system of claim 1, wherein at least one of the plurality of antennas is a sector-antenna.

10. The base station system of claim 1, wherein at least one of the plurality of antennas is an omni-directional antenna.

11. The base station 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;

or

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.

12. The base station system of claim 11, wherein the plurality of antenna elements are two-dimensional antenna elements.

13. The base station system of claim 11, wherein the plurality of antenna elements are three-dimensional antenna elements.

14. The base station system of claim 11, wherein the azimuth pattern is created by weighting subcarriers in the frequency domain within the beamformers.

15. The base station system of claim 11, 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.

16. The base station system of claim 1, further comprising a plurality of signal distribution networks coupled to the plurality of antennas.

17. The base station 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.

18. The base station system of claim 1, 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.

19. The base station system of claim 1, the controller further enabling the base station system to be switched between a plurality of modes of operation.

20. A method of transmitting signals to mobile devices with a base station system for cellular communication and broadcasting in a multi-cell orthogonal frequency division multiplexing (OFDM) wireless network, the method comprising:

identifying a first beam pattern suitable for transmitting signals to mobile devices within a cell 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 one of a plurality of antennas by turning on one of multiple switches for transmission to the cell, wherein the routing and amplification are selected in order to generate the first beam pattern suitable for transmitting signals to mobile devices within the cell for the first application;

identifying a second beam pattern suitable for transmitting signals to mobile devices in multiple cells for a second application using a second group of OFDM symbols, the second beam pattern being wider in azimuth than the first beam pattern, more extended in elevation than the first beam pattern, or wider in azimuth than the first beam pattern and more extended in elevation than the first beam pattern; and

reconfiguring the signal distribution network to route and amplify second signals from the one or more baseband processors to the plurality of antennas by turning on multiple switches for transmission to the multiple cells, wherein the routing and amplification are selected in order to generate the second beam pattern suitable for transmitting signals to mobile devices in multiple cells for the second application,

the reconfiguring taking place during a cyclic prefix or cyclic postfix between OFDM symbols.

21. The method of claim 20, wherein the first application is a unicasting application, and the second application is a broadcasting application.

22. The method of claim 20, wherein the routing in the signal distribution network is configured by turning on or off switches in the signal distribution network.

23. The method of claim 20, 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.

24. The method of claim 20, further comprising inserting a transition period between the transmission of the first signals and the second signals in order to allow the base station system to be reconfigured.