MULTIPLEXING SCHEMES FOR OFDMA

• US 20090022098A1
• Filed: 10/23/2006
• Published: 01/22/2009
• Est. Priority Date: 10/21/2005
• Status: Abandoned Application

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Zhu, Pelying, Novak, Robert, Vrzic, Sophie, Zhang, Hang, Tong, Wen, Ma, Jianglei, Fong, Mo-Han, Au, Kelvin Kar-Kin
• Application Number:
  US12/090,964
• Publication Number:
  US 20090022098A1
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 1/0013 Rate matching, e.g. puncturing or repetition of code symbols
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0067 Rate matching H04L1/0013 and H04L1/08 take precedence
• CPC Class Codes: H04L 1/14 in which the signals are sent back to the transmitter to be checked ; echo systems
• CPC Class Codes: H04L 1/1614 using bitmaps
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0042 intra-user or intra-terminal allocation
• CPC Class Codes: H04L 5/0046 Determination of how many bits are transmitted on different sub-channels
• CPC Class Codes: H04L 5/0064 Rate requirement of the data, e.g. scalable bandwidth, data priority
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04L 65/80 Responding to QoS

Abstract

Methods and systems are provided for allocating resources including VoIP (voice over Internet Protocol) and Non-VoIP resources. In some embodiments, multiplexing schemes are provided for use with OFDMA (orthogonal frequency division multiplexing access) systems, for example for use in transmitting VoIP traffic, in some embodiments, various HARQ (Hybrid Automatic request) techniques are provided for use with OFDMA systems. In various embodiments, there are provided methods and systems for dealing with issuea such as Handling non-full rate vocoder frames, VoIP packet jitter handling, VoIP capacity increasing schemes, persistent and non-persistent assignment of resources in OFDMA systems.

Claims

1-40. -40. (canceled)

41. A method comprising:

for nominal operating conditions, transmitting an ACK-NAK-echo bitmap or any type of ACK/NAK echo echoing the NAK(s) or ACK(s) sent by one or more wireless stations;

in some instances, transmitting the ACK-NAK-echo bitmap with an ACK to echo a NAK transmitted by the wireless station, or with an NAK to echo an ACK transmitted by the wireless station for the purpose of signalling something to the wireless station.

42. A method of performing resource assignment comprising:

sending a bitmap (or other signalling) containing a respective location for each of a plurality of wireless stations, with each wireless station'"'"'s relative position in the bitmap (or other signalling) being associated with some OFDM resource allocation;

wherein a value at a position in the bitmap (or other signalling), indicates whether or not a resource has been assigned to the receiver associated with that bitmap (or other signalling) position.

43. The method of claim 42 wherein for at least some wireless stations, the bitmap (or other signalling) allows each wireless station that has been assigned a non-persistent resource to derive what resource has been non-persistently assigned.

44. The method of claim 42 wherein a persistent allocation is used for a first transmission for each wireless station.

45. The method of claim 42 wherein the relative wireless station'"'"' positions in the bitmap (or other signalling) are also associated with a group of wireless stations, such that wireless stations belonging to a specific group can be uniquely identified by their position in the bitmap (or other signalling).

46. The method of claim 45 wherein the wireless stations of a given group include wireless stations that have their first HARQ sub-packet transmission occurring in the same slot within a HARQ interlace.

168. The method of claim 42 wherein a persistent allocation is used for a one or more HARQ transmissions for a wireless station.

47-83. -83. (canceled)

84. A method comprising:

transmitting frames using OFDM, each frame occupying a plurality of OFDM symbols;

signalling resource allocation to multiple groups of wireless stations using multiple bitmaps (or other signalling);

re-assigning unused resources available for at least one of the bitmap (or other signalling)s to another of the bitmaps (or other signalling).

85. The method of claims 84, wherein the frames are VoIP frames.

86. The method of claim 85 further comprising wireless stations that are receiving such unused resources reading their own bitmap (or other signalling) and the bitmap (or other signalling) of others to determine where their resources are.

87. The method of claim 86 further comprising:

starting resource allocation with the bitmap (or other signalling) associated with wireless stations with the worse channel conditions, and then in sequence according to channel conditions until concluding with the allocation for the bitmap (or other signalling) associated with receives with the best channel conditions.

88. The method of claim 87 further comprising performing resource allocation of a next bitmap (or other signalling) beginning with unused resources of the previous bitmap (or other signalling).

89. The method of claim 88 wherein only those wireless stations not receiving persistent allocation are repacked into unused resources of another bitmap (or other signalling).

90. The method of claim 85 further comprising:

for some wireless stations, allocating resources that are repacked from resources available to be assigned by bitmap (or other signalling) of those wireless stations, and making available unused resources for assignment to non-persistent wireless stations that are not part of the bitmap (or other signalling) signalled by some other method.

91. The method of claim 85 further comprising:

allocating a first wireless station to a resource from which a subset is removed due to its having been assigned to other wireless stations by a bitmap (or other signalling)signalling;

the first wireless station deriving which resources are already assigned to other wireless stations from knowledge of the first resource allocation and the bitmap (or other signalling) that signals the subset to be removed.

92. The method of claim 91 further comprising:

signalling to the first wireless station to indicate whether or not the wireless station must also read the bitmap(s) (or other signalling) signalling intended for other wireless stations, in order to derive which resources have already been assigned to other wireless stations.

93. The method of claim 92 wherein signalling comprises sending a single bit to indicate either 1) the wireless station is allocated all resources specified excluding those allocated to other wireless stations or 2) the bitmap (or other signalling) does not need to be read as all resources specified are assigned to the wireless station.

94-97. -97. (canceled)

98. A method comprising:

transmitting frames using OFDM, each frame occupying a plurality of OFDM symbols;

sending a first bitmap (or other signalling) to indicate which wireless stations are being allocated an OFDM resource during a given scheduling period;

sending a second bitmap (or other signalling) to indicate the size of resources and/or MCS'"'"'s of wireless stations assigned by the first bitmap (or other signalling).

99. The method of claim 98, wherein the frames are VoIP frames.

100. The method of claim 99 wherein the second bitmap (or other signalling) contains an entry for each wireless station that is actively being assigned by the first bitmap (or other signalling).

101. The method of claim 100 wherein each entry is a single bit that indicates small or large resource assignment.

102. The method of claim 99 wherein the second bitmap (or other signalling) contains entries for persistently assigned wireless stations, regardless of whether or not they are assigned, the method further comprising other wireless stations deriving their resource allocations taking into account the second bitmap (or other signalling).

103. The method of claim 99 wherein the second bitmap (or other signalling) does not contain entries for persistently assigned wireless stations.

104. A method comprising:

transmitting frames using OFDM, each frame occupying a plurality of OFDM symbols;

transmitting a respective bitmap (or other signalling) for each of a plurality of HARQ interlaces.

105. The method of claim 104, wherein the frames are VoIP frames.

106. The method of claim 105 further comprising:

for at least some wireless station, assigning multiple positions in one or more bitmaps (or other signalling) in one or more user groups, a user group comprising a set of wireless stations having the same start position of the first HARQ transmission of a sub-packet for a given interlace.

107. The method of claim 106 comprising for at least some wireless stations:

assigning wireless stations to a bitmap (or other signalling), and possibly a user group, for a primary assignment, and another position on another or the same bitmap (or other signalling), in another or the same user group, for the purpose of a secondary assignment.

108. The method of claim 107 wherein the first transmission is persistently assigned for either the primary or secondary assignments, or both.

109. The method of claim 107 wherein the secondary assignment may be shared by more than one wireless station while the primary assignment is unique.

110. The method of claim 107 wherein start slots and interlaces may be different for the primary and secondary interlaces.

111. The method of claim 107 wherein:

a packet that begins transmission for the primary assignment continues all re-transmissions using the allocations for the primary assignment;

a packet that begins transmission for the secondary assignment continues all re-transmissions using the secondary assignment.

112. The method of claim 107 further comprising:

starting transmission of a packet using the primary assignment and switching to the secondary assignment after some number of re-transmissions.

113. The method of claim 107 further comprising persistently assigning resources to the first transmission of the primary and secondary assignments, where the first transmissions of the secondary assignment is not allowed to be the first transmission of the packet.

114. The method of claim 107 wherein resources are persistently assigned to the first transmission of the primary assignment but not the secondary assignments.

115. The method of claim 107 wherein:

some user groups of a given bitmap (or other signalling) refer to wireless stations with start positions of the first HARQ transmission of a sub-packet in a given slot, and may be persistently assigned, while other user groups in the same bitmap (or other signalling) may not be persistently assigned.

116. The method of claim 107 wherein the presence of a secondary first slot persistent assignment requires the wireless station to monitor the secondary channel.

117. The method of claim 107 wherein the secondary assignment is only used when needed due to re-transmissions being exhausted on the primary assignment.

118-167. -167. (canceled)

169. A method of performing resource assignment wherein a persistent allocation is used for a HARQ first transmission for a wireless station.

170. A method of performing resource assignment wherein a persistent allocation is used for one or more HARQ transmissions for a wireless station.