US-12628003-B2 - Multiple-antenna system for cell-specific and user-specific transmission

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.

Inventors

• Titus Lo
• Xiaodong Li

Assignees

• NEO WIRELESS LLC

Dates

Publication Date

20260512

Application Date

20231121

Claims (20)

1. 1 . A method performed by an apparatus for wireless transmission, the method comprising: transmitting control information associated with an orthogonal frequency division multiple access (OFDMA) transmission; and transmitting the OFDMA transmission including at least a first beam pattern that carries first unicast data and a second beam pattern that carries second unicast data that is transmitted at least in-part simultaneously with the first unicast data, wherein the OFDMA transmission is formed by: allocating a first set of subcarriers to a first recipient device and a second set of subcarriers to a second recipient device, wherein the first set of subcarriers includes first user-specific data subcarriers and first pilot subcarriers and the second set of subcarriers includes second user-specific data subcarriers and second pilot subcarriers; and applying a first set of complex weights to the first set of subcarriers to form the first beam pattern and applying a second set of complex weights to the second set of subcarriers to form the second beam pattern.
2. 2 . The method of claim 1 , wherein the control information includes downlink resource allocation information indicating the first set of subcarriers and the second set of subcarriers.
3. 3 . The method of claim 1 , wherein the control information allocates first groups of subcarriers to the first recipient device and allocates second groups of subcarriers to the second recipient device.
4. 4 . The method of claim 3 , wherein the control information includes a preamble.
5. 5 . The method of claim 4 , wherein the preamble is decodable by the first recipient device and the second recipient device.
6. 6 . The method of claim 1 , further comprising transmitting a mid-amble.
7. 7 . The method of claim 1 , wherein applying the first set of complex weights includes: applying a complex weight per subcarrier; or applying a subset of complex weights per a group of multiple subcarriers.
8. 8 . The method of claim 1 , wherein the first beam pattern is directionally different in azimuth than the second beam pattern.
9. 9 . The method of claim 1 , wherein the first beam pattern is directionally different in elevation than the second beam pattern.
10. 10 . The method of claim 1 , wherein the OFDMA transmission is based on modulation and coding using link adaptation.
11. 11 . The method of claim 1 , wherein a more robust modulation and coding is used for the control information than used for the first unicast data and used for the second unicast data.
12. 12 . The method of claim 1 , wherein the transmitting the OFDMA transmission further includes forward error correction encoding, interleaving, modulation, and mapping modulated data to subcarriers.
13. 13 . The method of claim 1 , wherein the transmitting the OFDMA transmission further includes: performing an inverse transform on the first set of subcarriers and the second set of subcarriers to generate time domain orthogonal frequency divisional multiplexing (OFDM) symbols; adding cyclic prefixes onto the time domain OFDM symbols; and transmitting the time domain OFDM symbols and cyclic prefixes via a plurality of antennas.
14. 14 . The method of claim 1 , wherein the transmitting the OFDMA transmission includes transmitting at least a portion of the first unicast data and at least a portion of the second unicast data in a same orthogonal frequency division (OFDM) symbol that includes both the first set of subcarriers and the second set of subcarriers.
15. 15 . The method of claim 1 , wherein the unicast data includes a frame control field.
16. 16 . An apparatus comprising: a controller and a transmitter; wherein the controller and the transmitter are collectively configured to: transmit control information associated with an orthogonal frequency division multiple access (OFDMA) transmission; and transmit the OFDMA transmission including at least a first beam pattern that carries first unicast data and a second beam pattern that carries second unicast data that is transmitted at least in-part simultaneously with the first unicast data, wherein the OFDMA transmission is formed by: allocating a first set of subcarriers to a first recipient device and a second set of subcarriers to a second recipient device, wherein the first set of subcarriers includes first user-specific data subcarriers and first pilot subcarriers and the second set of subcarriers includes second user-specific data subcarriers and second pilot subcarriers; and applying a first set of complex weights to the first set of subcarriers to form the first beam pattern and applying a second set of complex weights to the second set of subcarriers to form the second beam pattern.
17. 17 . The apparatus of claim 16 , wherein the control information allocates first groups of subcarriers to the first recipient device and allocates second groups of subcarriers to the second recipient device, and wherein the control information includes a preamble that is decodable by the first recipient device and the second recipient device.
18. 18 . The apparatus of claim 16 , wherein: a complex weight is applied per subcarrier; or a subset of complex weights is applied per a group of multiple subcarriers.
19. 19 . The apparatus of claim 16 , further comprising a plurality of antennas, wherein the controller and the transmitter are further collectively configured to: perform an inverse transform on the first set of subcarriers and the second set of subcarriers to generate time domain orthogonal frequency divisional multiplexing (OFDM) symbols; add cyclic prefixes onto the time domain OFDM symbols; and transmit the time domain OFDM symbols and cyclic prefixes via the plurality of antennas.
20. 20 . The apparatus of claim 16 , wherein the controller and the transmitter are further collectively configured to transmit at least a portion of the first unicast data and at least a portion of the second unicast data in a same orthogonal frequency division (OFDM) symbol that includes both the first set of subcarriers and the second set of subcarriers.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS(S) This application is a continuation of U.S. patent application Ser. No. 17/544,482, filed Dec. 7, 2021, which issued as U.S. Pat. No. 11,825,314 on Nov. 21, 2023, which is a continuation of U.S. patent application Ser. No. 16/788,872, filed Feb. 12, 2020, which issued as U.S. Pat. No. 11,197,172 on Dec. 7, 2021, which is a continuation of U.S. patent application Ser. No. 16/208,491, filed Dec. 3, 2018, which issued as U.S. Pat. No. 10,567,976 on Feb. 18, 2020, which is a continuation of U.S. patent application Ser. No. 15/155,975, filed May 16, 2016, which issued as U.S. Pat. No. 10,149,173 on Dec. 4, 2018, which is a continuation of U.S. patent application Ser. No. 14/725,254, filed May 29, 2015, which issued as U.S. Pat. No. 9,344,313 on May 17, 2016, which is a continuation of Ser. No. 13/668,102, filed Nov. 2, 2012, which issued as U.S. Pat. No. 9,048,540 on Jun. 2, 2015, which is a continuation of Ser. No. 13/396,487, filed Feb. 14, 2012, which issued as U.S. Pat. No. 8,326,366 on Dec. 4, 2012, which is a continuation of U.S. patent application Ser. No. 13/276,240, filed on Oct. 18, 2011, which issued as U.S. Pat. No. 8,116,822 on Feb. 14, 2012, which is a continuation of U.S. patent application Ser. No. 11/908,262, filed on Oct. 30, 2008, which issued as U.S. Pat. No. 8,041,395 on Oct. 18, 2011, which is the U.S. National Stage, under 35 U.S.C. § 371, of International Patent Application No. PCT/US06/060888, filed on Nov. 14, 2006, which claims the benefit of U.S. Provisional Application No. 60/736,500, filed on Nov. 14, 2005, the contents of which are hereby incorporated by reference herein. TECHNICAL FIELD The disclosed embodiments relate, in general, to wireless communication and, in particular, to antenna systems for use in cellular communication and broadcasting. BACKGROUND An antenna system is an indispensable component of any wireless communication network. Wireless communications is presently available in many forms, among which the most common one is cellular/mobile communications. In a cellular wireless network, the geographical region to be services by the network is normally divided into smaller areas called cells. Within each cell are mobile stations (MSs) that are used by users to access the network. A cell may be further divided into multiple sectors and in each sector the coverage is provided by a base station (BS). A BS also serves as a focal point to distribute information to and collect information from MSs that are located in the cell by radio signals that are transmitted by the BS antenna. There are different types of transmissions carried out by BSs. A BS can send specific data to an individual MS within its sector; a BS may also send a set of common data to all the MSs with its sector; a BS may also send data via a common channel to all the MSs within a cell; and a group of BSs may broadcast information via a common channel simultaneously to all MSs within a group of cells. Depending on the type of transmission, a distinctive set of requirements may be required for the BS antenna system in terms of radiation patterns, power settings; etc. In addition, a frequency-reuse scheme may impose constraints on the antenna system. The extent to which an antenna system meets the wide range of requirements and constraints directly impacts on the wireless network performance. Therefore, there is a need to create an antenna system that is reconfigurable, adjustable, and controllable to enable a BS to carry out transmissions from a type of application to the other. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates the coverage of a wireless communication network that is comprised of a plurality of cells. FIG. 2 is a block diagram of a receiver and a transmitter, such as might be used in a multi-carrier wireless communication network. FIG. 3 is a graphical depiction of a multi-carrier signal structure in the time domain. FIG. 4 is a block diagram of a particular realization of a transmitter for cellular communication and broadcast. FIG. 5 is a block diagram of a variant realization of a transmitter for cellular communication and broadcast. FIG. 6 is a block diagram of a distribution network used in a transmitter for cellular communication and broadcast. FIGS. 7A and 7B are block diagrams of alternate implementations of the distribution network. FIG. 8 is a graphical depiction of using different types of antenna beams for different types of transmissions. FIG. 9 is a graphical depiction of using a conformed elevation beam for unicast and sector-specific broadcast and an extended elevation beam for broadcast. FIGS. 10A and 10B are perspective views of examples of antenna systems. FIG. 11 is a block diagram of a beamforming process in an OFDMA system. FIG. 12 is a perspective view of an antenna that generates different elevation beams. FIG. 13 is a block diagram of a bank of N distribution networks used in beamforming, transmit-diversity, or MIMO applica