Multiple-antenna system for cell-specific and user-specific transmission

• US 9,344,313 B2
• Filed: 05/29/2015
• Issued: 05/17/2016
• 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): Jain, Ankur
• Application Number:
  US14/725,254
• Publication Number:
  US 20150263874A1
• Time in Patent Office: 354 Days
• Field of Search: 455/550.1
• US Class Current: 1/1
• 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 reception method and apparatus for use in a multi-cell orthogonal frequency division multiple access (OFDMA) wireless system. In a unicast receive mode during a first receive time period, a first group of orthogonal frequency division multiplexing (OFDM) symbols is received by a mobile device from multiple of a plurality of antennas at a serving base station. In a single-frequency-network (SFN) receive mode during a second receive time period, a second group of OFDM symbols is received by the mobile device from one of a plurality of antennas at the serving base station. The transition between the first receive time period and the second receive time period occurs during a cyclic prefix or a cyclic postfix between OFDM symbols, and the plurality of antennas produce a first beam pattern during the unicast receive mode and a second beam pattern during the SFN receive mode.

Claims

1. A transmission method for a base station in a cell of an orthogonal frequency division multiplexing (OFDM) wireless system, the base station including a plurality of antennas and a plurality of circuits coupled to the plurality of antennas, the method comprising:

generating a first set of signals by modulating a plurality of cell-specific subcarriers in a first transmission mode for transmission to mobile devices within the cell;

generating a second set of signals by modulating a plurality of user-specific subcarriers in a second transmission mode for transmission to a specific mobile device within the cell;

maintaining a mapping of a plurality of circuits coupled to the plurality of antennas and associated with the first transmission mode and the second transmission mode, the mapping causing the first set of signals to be routed to a first group of the plurality of antennas in the first transmission mode and causing the second set of signals to be routed to a second group of the plurality of antennas in the second transmission mode;

transmitting the first set of signals by activating a first group of the plurality of circuits reflected by the mapping; and

transmitting the second set of signals by activating a second group of the plurality of circuits reflected by the mapping;

wherein the first group of antennas produce a first beam pattern for the first transmission mode and the second group of antennas produce a second beam pattern for the second transmission mode, and wherein the first beam pattern is different than the second beam pattern in either an azimuth pattern or an elevation pattern.

2. The method of claim 1, wherein the plurality of cell-specific subcarriers comprise cell-specific data subcarriers and cell-specific pilot subcarriers.

3. The method of claim 1, wherein the plurality of user-specific subcarriers comprise user-specific data subcarriers and user-specific pilot subcarriers.

4. The method of claim 1, further comprising weighting the first or second set of signals in a digital or analog domain.

5. The method of claim 1, further comprising weighting the first or second set of signals in a time or frequency domain.

6. The method of claim 1, wherein transmitting the first and second sets of signals further comprises transmitting with beamforming, transmit diversity, or multiple-input multiple output (MIMO) transmission.

7. The method of claim 1, further comprising dividing a transmission time period associated with the first and second sets of signals into a plurality of frames, wherein each frame contains a plurality of subframes, each subframe contains a plurality of time slots, and each time slot contains a plurality of OFDM symbols.

8. A base station in a cell of an orthogonal frequency division multiplexing (OFDM) wireless system, the base station comprising:

a plurality of antennas;

a plurality of circuits coupled to the plurality of antennas;

a transmitter configured to generate a first set of signals by modulating a plurality of cell-specific subcarriers in a first transmission mode for transmission to mobile devices within the cell;

the transmitter configured to generate a second set of second signals by modulating a plurality of user-specific subcarriers in a second transmission mode for transmission to a specific mobile device within the cell;

a controller configured to maintain a mapping of a plurality of circuits coupled to the plurality of antennas and associated with the first transmission mode and the second transmission mode, the mapping causing the first set of signals to be routed to a first group of the plurality of antennas in the first transmission mode by activating a first group of the plurality of circuits, and causing the second set of signals to be routed to a second group of the plurality of antennas in the second transmission mode by activating a second group of the plurality of circuits; and

the transmitter configured to transmit the first set of signals associated with the first transmission mode and the second set of signals associated with the first transmission mode;

wherein the first group of antennas produce a first beam pattern for the first transmission mode and the second group of antennas produce a second beam pattern for the second transmission mode, and wherein the first beam pattern is different than the second beam pattern in either an azimuth pattern or an elevation pattern.

9. The base station of claim 8, wherein the plurality of cell-specific subcarriers comprise cell-specific data subcarriers and cell-specific pilot subcarriers.

10. The base station of claim 8, wherein the plurality of user-specific subcarriers comprise user-specific data subcarriers and user-specific pilot subcarriers.

11. The base station of claim 8, wherein at least one of the plurality of antennas is a sector-antenna.

12. The base station of claim 8, wherein at least one of the plurality of antennas is an omni-directional antenna.

13. The base station of claim 8, wherein the transmitter is further configured to perform beamforming, transmit diversity, or multiple-input multiple output (MIMO) transmission.

14. The base station of claim 8, wherein the transmitter comprises a channel encoding and modulation component, and an inverse fast Fourier transform (IFFT) component.

15. The base station of claim 8, wherein a transmission time period associated with the first and second sets of signals is divided into a plurality of frames and each frame contains a plurality of subframes, each subframe contains a plurality of time slots, and each time slot contains a plurality of OFDM symbols.