Wireless communication methods, systems, and signal structures

• US 20070105508A1
• Filed: 12/15/2006
• Published: 05/10/2007
• Est. Priority Date: 04/02/2004
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Jianglei Ma, Ming Jia, Peiying Zhu, Wen Tong
• Inventors: Tong, Wen, Ma, Jianglei, Zhu, Peiying, Jia, Ming
• Granted Patent: US 7,876,840 B2
• Time in Patent Office: Days
• US Class Current: 455/101
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04B 2001/6908 using time hopping
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04B 7/0667 of delayed versions of same signal using space-time coding H04L1/0618
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• CPC Class Codes: H04B 7/0697 using spatial multiplexing
• CPC Class Codes: H04J 11/00 Orthogonal multiplex systems, e.g. using WALSH codesH04J13/00 takes precedence
• CPC Class Codes: H04J 13/0074 Code shifting or hopping
• CPC Class Codes: H04J 13/18 Allocation of orthogonal codes
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0068 by puncturing
• CPC Class Codes: H04L 1/0069 Puncturing patterns
• CPC Class Codes: H04L 1/0072 Error control for data other than payload data, e.g. control data
• CPC Class Codes: H04L 1/0625 Transmitter arrangements
• CPC Class Codes: H04L 1/0668 Orthogonal systems, e.g. using Alamouti codes
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1819 with retransmission of additional or different redundancy
• CPC Class Codes: H04L 1/1845 Combining techniques, e.g. code combining
• CPC Class Codes: H04L 1/1867 : Arrangements specially adapted for the transmitter end
• CPC Class Codes: H04L 25/0204 : of multiple channels
• CPC Class Codes: H04L 25/0226 : sounding signals per se
• CPC Class Codes: H04L 25/0242 : using matrix methods
• CPC Class Codes: H04L 27/2602 : Signal structure
• CPC Class Codes: H04L 5/0023 : Time-frequency-space
• CPC Class Codes: H04L 5/0035 : Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04L 5/0044 : allocation of payload
• CPC Class Codes: H04L 5/0048 : Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/006 : Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/1469 : using time-sharing

Abstract

Systems and methods for performing OFDM MIMO communications are provided. These include a frame structure; methods of combining various types of MIMO such as STTD and SM; sub-channel definitions; sub-FFT channel constructions; fast control channels; additional modulations; and group antenna transmit diversity; new incremental redundancy schemes.

Claims

1-53. -53. (canceled)

54. A method of transmitting a TDD frame structure comprising:

defining a plurality of time slots each comprising at least two OFDM symbols;

defining at least one fixed switching point;

defining at least one flexible switching point,

wherein at each fixed switching point, a predetermined one of uplink or downlink transmission is performed;

at each flexible switching point, a direction of communications is optionally switched.

55. The method of claim 54 wherein all of the switching points are at slot boundaries.

56. The method of claim 54 wherein at least one of the flexible switching points is not on a slot boundary.

57. The method of claim 54 wherein each period of uplink transmission is delineated by a TTG (transmit transition gap) and a RTG (receive transition gap) that are collectively substantially equal in duration to an OFDM symbol pair, wherein for pairs of consecutive slots during which no TTG and RTG is necessary, an OFDM symbol pair is transmitted instead.

58. A MIMO OFDM transmitter adapted to implement the method of claim 54.

59-61. -61. (canceled)

62. A method of transmitting a TDD frame structure comprising:

defining a plurality of TDD slots each comprising at least two OFDM symbols;

at TDD slot boundaries, defining at least one fixed switching point and at least one flexible switching point;

wherein at each fixed switching point, a predetermined one of uplink or downlink transmission is performed;

wherein at each flexible switching point, uplink or downlink transmission can be scheduled;

wherein the fixed switching point(s) are common across a network, and the flexible switching point(s) are selected on a cell/beam specific basis.

63. The method of claim 62 further comprising:

transmitting the frame structure at each of a plurality of base stations forming a network such that the fixed switching point(s) are common across the network, and the flexible switching point(s) are selected on a cell/beam specific basis.

64. The method of claim 62 wherein each TDD slot comprises a plurality of pairs of OFDM symbols and a tail symbol, the method further comprising at each transition point performing one of:

if there is an DL/UL (downlink/uplink) switch scheduled at that transition point, separating the tail symbol into two parts, one serving as TTG (transmit transition gap), and the other serving as RTG (receive transition gap);

if there is no DL/UL switch scheduled at that transition point, using the tail symbol as a regular traffic OFDM symbol.

65. The method of claim 64 wherein using the tail symbol as a regular traffic OFDM symbol comprises combining the tail symbol with another tail symbol in an adjacent TDD slot to generate an OFDM symbol pair.

66. The method of claim 65 wherein each TDD frame has a duration of 10 ms.

67. The method of claim 66 wherein each TDD frame comprises five TDD slots each with a duration of 2 ms, and each consisting of 9 OFDM symbol pairs and one tail symbol.

68. The method of claim 67 wherein each pair of OFDM symbols is space time coded.

69. The method of claim 62 wherein the fixed switching points are at slot boundaries, and the flexible switching points are at slot boundaries or within specific slots.

70. A MIMO OFDM transmitter adapted to implement the method of claim 62.

71. An OFDM receiver adapted to process signals generated in accordance with claim 62.

72. An OFDM communications system adapted to implement the method of claim 62.

73. A method comprising:

defining TDD slots each comprising a plurality of OFDM symbols for traffic and a tail symbol;

for at least some slots, using the tail symbol as a TTG or RTG to facilitate switching between uplink and downlink transmission or vice versa;

for at least some slots during which there is to be no switch between uplink and downlink transmission or vice versa allocating the tail symbol for traffic.

74. The method of claim 73 wherein allocating the tail symbol for traffic comprises combining the tail symbol with another tail symbol in an adjacent TDD slot to generate an OFDM symbol pair.