The present invention generally relates to allocation of radio resources for transmission in a wireless communication system. Specifically, the present invention relates to a novel method of signaling the allocation of radio resource for transmission in, e.g., orthogonal frequency division multiplexing (OFDM) and orthogonal frequency division multiple access (OFDMA) communication systems, and the resulting systems.
In an OFDMA communication system, the time-frequency resources of the system are shared among a plurality of mobile stations. The base station assigns resources to mobile stations using an assignment message, which is transmitted as part of a control channel. To minimize control channel overhead, it is known for the base station to make persistent assignments, wherein the assignment message is transmitted to the mobile station initially to indicate the assigned time-frequency resource, and then the base station uses the same time-frequency resource for subsequent transmissions to the mobile station. These transmissions can be hybrid automatic repeat request (HARQ) transmissions of the same packet or for subsequent transmissions of different packets. The initially assigned time-frequency resource is maintained by the base station for the mobile station until a timer elapses, a voice over internet protocol (VoIP) talk-spurt is completed, a VoIP call is completed, a certain number of negative acknowledgements is determined by the base station, or until the resource is explicitly or implicitly de-assigned by the base station.
During the period of the persistent allocation, there are times when the base station does not have any new packets to transmit to the mobile station. For example, if the mobile station has acknowledged a HARQ packet before the maximum number of HARQ transmission attempts is reached, the base station may not have a new packet for the mobile station. Alternatively, if the base station has determined a discontinuous transmission (DTX) state for a VoIP mobile station, the base station may not have a packet to transmit to the mobile station. During such times, it is desirable for the base station to temporarily allocate the persistently assigned resource for a first mobile station to a second mobile station without de-assigning the first mobile station. To meet the quality of service (QoS) requirements of the first mobile station, it is also desirable for the base station to be able to resume utilizing the persistently assigned resource for the first mobile station once it receives a new packet for the first mobile station. Such QoS requirements typically impose the restriction that the temporary assignment is not itself a persistent assignment, thereby requiring even more temporary assignments. These temporary assignments create additional control channel overhead. For an OFDMA communication system with a large number of VoIP mobile stations, the number of temporary assignments can be large, which can dramatically increase the control channel overhead. Thus, there is a need for making large numbers of temporary assignments, while efficiently controlling the control channel overhead, while maintaining the desired QoS for the mobile stations.
In one aspect, the present invention provides for a method of assigning a radio resource in a wireless communication system. The method includes transmitting an assignment message to at least one mobile station including an indication of a virtual resource assignment, the virtual resource assignment corresponding to one or more virtual resources, and transmitting a remapping bitmap to the at least one mobile station, the remapping bitmap containing a bitmap that maps virtual resources to real resources.
In another aspect, the invention provides for a method of receiving a radio resource assignment in a wireless communication system. The method includes receiving an assignment message including an indication of a virtual resource assignment, the virtual resource assignment corresponding to one or more virtual resources, and receiving a remapping bitmap, the remapping bitmap containing a bitmap that maps virtual resources to real resources. The method further includes determining if one or more assigned virtual resources is being remapped to a real resource based on the remapping bitmap, and determining a real resource assignment as one or more real resources by mapping the virtual resources that have been remapped to real resources.
In yet another aspect, the present invention provides for a method of controlling quality of service (QoS) requirements for a first mobile station having a first QoS requirement and a second mobile station having a second QoS requirement comprising assigning the first mobile station having the first QoS requirement to a real resource, and assigning the second mobile station having the second QoS requirement to a virtual resource. The method further includes transmitting a remapping bitmap to the second mobile station having the second QoS requirement, the remapping bitmap providing an index relating the virtual resource to a real resource.
An advantageous feature of embodiments of the present invention is the ability of a base station to indicate temporary assignments to mobile stations reliably while minimizing the control channel overhead.
Another advantageous feature of embodiments of the present invention is the ability to detect the temporary assignment from the base station reliably.
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which:
The present disclosure can be described by the embodiments given below. It is understood, however, that the embodiments below are not necessarily limitations to the present disclosure, but are used to describe a typical implementation of the invention.
The present invention provides a unique method and apparatus for sharing resources in a wireless system. It is understood, however, that the following disclosure provides many different embodiments, or examples, for implementing different features of the invention. Specific examples of components, signals, messages, protocols, and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to limit the invention from that described in the claims. Well known elements are presented without detailed description in order not to obscure the present invention in unnecessary detail. For the most part, details unnecessary to obtain a complete understanding of the present invention have been omitted inasmuch as such details are within the skills of persons of ordinary skill in the relevant art. Details regarding control circuitry described herein are omitted, as such control circuits are within the skills of persons of ordinary skill in the relevant art.
In this example, the fourth through eleventh DL OFDM symbols are allocated as a zone 300 inside which 15 distinct time-frequency resource assignments are possible. Each distinct time-frequency resource assignment is referred to as a node. The set of nodes is illustrated in
For the case when persistent assignments are made by the base station, there needs to be an efficient way of allocating holes left by the persistently assigned mobile stations to other mobile stations. For example, referring again to
To mitigate the control channel overhead associated with temporarily assigning resources to mobile stations,
To understand the interpretation of these bitmaps,
The tree structure is used to ensure than any assignment can be represented by a series of real base nodes. For example, the assignment of real node 3 is equivalent to the assignment of real base nodes 7 and 8. Virtual channel tree 904 mirrors real channel tree 902. Virtual parent node 930 corresponds to a virtual resource equivalent to the real resource which corresponds to real parent node 910 of real channel tree 902. Virtual base nodes 940 correspond to virtual resources equivalent to the real resources which correspond to real base nodes 920 of real channel tree 902. In some embodiments, the size of real channel tree 902 is different from the size of virtual channel tree 904. More particularly, the number of channel tree levels in real channel tree 902 can be different from the number of channel tree levels in virtual channel tree 904. For example, in some embodiments, virtual channel tree 904 only has only one level, the base node level. In some embodiments, virtual channel tree 904 is referred to as a leftover channel tree.
Returning to
In some embodiments, two or more of the resource availability bitmap 812, the virtual resource bitmap 814, and the offset field 816 are concatenated and encoded jointly for transmission by the base station. In this case, the base station may transmit an indication of which time-frequency resources will be used to transmit the concatenated packet, using a control channel, to the mobile station. This indication can be a layer three signaling message or can be transmitted as part of a periodic overhead message transmission. For example, the base station can indicate to the mobile station that a remapping bitmap 810 containing a resource availability bitmap 812, a virtual resource bitmap 814, and an offset field 816 is transmitted on control channel resource N using a layer three signaling message.
In an alternate embodiment, resource availability bitmap 812, if used, virtual resource bitmap 814, if used, and offset field 816, if used, are encoded separately for transmission by the base station. Alternatively, offset field 816 may be concatenated with either resource availability bitmap 812 or virtual resource bitmap 814 prior to encoding. As an example, for the case when there is a resource availability bitmap 812 and a virtual resource bitmap 814, resource availability bitmap 812 is encoded and transmitted on one control channel resource and virtual resource bitmap 814 is encoded on a different control channel resource. In some embodiments, the control channel resource for resource availability bitmap 812 determines the control channel resource for virtual resource bitmap 814. For example, if resource availability bitmap 812 is transmitted on control channel resource N, then virtual resource bitmap 814 is transmitted on resource N+1. In other embodiments, a type header is added to the control channel transmission to distinguish between resource availability bitmap 812 and virtual resource bitmap 814. For example, a 1 bit type header could be added to the control channel, where a ‘0’ indicates that the following information is a resource availability bitmap 812 and a ‘1’ indicates that the following information is a virtual resource bitmap 814. If downlink and uplink are simultaneously supported using remapping bitmap 810, as will be described in more detail below, a 2 bit type header could be added to the control channel, where ‘00’ indicates that the following information is a downlink resource availability bitmap 812, ‘01’ indicates that the following information is a downlink virtual resource bitmap 814, ‘10’ indicates that the following information is an uplink resource availability bitmap 812, and ‘11’ indicates that the following information is an uplink virtual resource bitmap 814.
In some embodiments, a base station implicitly indicates the type of bitmap based on the chosen control channel resource. For example, a base station can always transmit a resource availability bitmap 812 on odd control channel resources and can always transmit a virtual resource bitmap 814 on even control channel resources. If downlink and uplink are simultaneously supported using remapping bitmap 810, the base station can always transmit a DL resource availability bitmap 812 using a control channel resource X, such that mod(X,4)=0. Similarly, the base station can always transmit a DL virtual resource bitmap 814 using a control channel resource X, such that mod(X,4)=1, can always transmit an UL resource availability bitmap 812 using a control channel resource X, such that mod(X,4)=2, and can always transmit an UL virtual resource bitmap 814 using a control channel resource X, such that mod(X,4)=3.
In other alternate embodiments, the location of resource availability bitmap 812 and virtual resource bitmap 814 is indicated by a base station to a mobile station using an overhead message, which is transmitted periodically by the base station. For example, the overhead message can indicate that resource availability bitmap 812, when transmitted, is transmitted on control channel resource X, and virtual resource bitmap 814, when transmitted, is transmitted on control channel resource Y.
In another alternate embodiment, the base station distinguishes between resource availability bitmap 812 and virtual resource bitmap 814 using different scrambling for each bitmap. Similarly, a base station can distinguish between resource availability bitmap 812 and virtual resource bitmap 814 by using different cyclic redundancy check (CRC) sequences for each bitmap. For each case, a mobile station performs multiple hypothesis decoding assuming one of the known possibilities for scrambling or CRC. For example, the base station can transmit the resource availability bitmap 812 with CRC1 and can transmit the virtual resource bitmap 814 with CRC2. Upon receipt of a particular control channel resource, the mobile station decodes the packet and then performs a CRC using a known CRC. If the CRC check is successful for CRC1, the mobile station determines that a resource availability bitmap 812 was transmitted. Similarly, if the CRC check is successful for CRC2, the mobile station determines that a virtual resource bitmap 814 was transmitted.
Using the concept of a real channel tree 902 and a virtual channel tree 904, the base station can assign mobile stations either real resources or virtual resources using the assignment message. In the event that the mobile station is assigned a virtual resource, the mobile station processes the remapping bitmap 810 to determine its real resource assignment. Four types of virtual resource assignment are possible, as will be described below. Further below, the manner in which a mobile station determines the type of assignment it is receiving will be described, with regard to
Type 1: For type 1 assignments, the mobile station processes virtual assignments by examining the bits in resource availability bitmap 812, virtual resource bitmap 814, and offset field 816, if used. Consider the case where the bits in resource availability bitmap 812 and virtual resource bitmap 814 correspond to base nodes of their respective channel trees. A ‘1’ in resource availability bitmap 812 means the corresponding real base node is not available, and a ‘0’ in resource availability bitmap 812 means the corresponding real base node is available. A ‘1’ in virtual resource bitmap 814 means the corresponding virtual base node is being mapped to a real base node for the current frame, and ‘0’ in virtual resource bitmap 814 means the corresponding virtual base node is not being mapped to a real base node for the current frame. Note that the interpretation of ‘0’ and ‘1’ could be reversed for one or both of resource availability bitmap 812 and virtual resource bitmap 814. In this embodiment, the virtual base node corresponding to the Nth ‘1’ in virtual resource bitmap 814 is mapped to the real base node corresponding to the Nth ‘0’ in resource availability bitmap 812.
The enumeration from 1 to N can begin with the lowest numbered base node or the highest numbered base node depending on the application. Further, the enumeration can change from frame to frame. For example, the enumeration from 1 to N can begin with the lowest numbered base node in even frames and the highest numbered base node in odd frames. In some embodiments, a single bit indicator is added to the remapping bitmap to indicate whether the enumeration from 1 to N begins with the lowest numbered base node or the highest numbered base node. In some embodiments, an indication of the enumeration is transmitted from the base station to the mobile station using a different message, for example a layer three signaling message.
The offset field 816, if used, indicates an offset to this mapping. In particular, denote the value of the offset field as OS. In this case, the virtual base node corresponding to the Nth ‘1’ in virtual resource bitmap 814 is mapped to the real base node corresponding to the (N+OS)th ‘0’ in resource availability bitmap 812.
If a mobile station receives a type 1 virtual assignment via the assignment message, the mobile station determines its real assignment as follows. First, the mobile station determines which virtual base nodes make up the assigned virtual node. Second, the mobile station decodes remapping bitmap 810 and extracts resource availability bitmap 812 and virtual resource bitmap 814. Third, for each virtual base node in the assignment, the mobile station determines if the bit corresponding to the virtual base node in the virtual resource bitmap is set to ‘1’. If so, the mobile station maps the virtual base node to a real base node as described above. Fourth, the mobile station determines its real assignment as the collection of real base nodes.
MS0: MS0 determines that virtual node 8 is a virtual base node and therefore corresponds to the second bit position in the virtual resource bitmap 1014. MS0 determines that its assigned virtual resource is being remapped to a real resource, since the bit corresponding to virtual base node 8 is a ‘1’. MS0 determines its assigned real resource as real base node 8 based on the rule that Nth ‘1’ in the virtual resource bitmap 1014 corresponds to the Nth ‘0’ in the resource availability bitmap 1012.
MS1: MS1 determines that virtual node 9 is a virtual base node and therefore corresponds to the third bit position in the virtual resource bitmap. MS1 determines that its assigned virtual resource is not being remapped to a real resource, since the bit corresponding to virtual base node 9 is a ‘0’. Hence, MS1 need not monitor traffic for some period of time, e.g. four frames, as no resources have been assigned to MS1.
MS2: MS2 determines that virtual node 5 maps to virtual base nodes 11 and 12 (see virtual channel tree 904 of
MS4: MS4 determines that virtual node 14 is a virtual base node and therefore corresponds to the eighth bit position in the virtual resource bitmap 1014. MS4 determines that its assigned virtual resource is being remapped to a real resource, since the bit corresponding to virtual base node 14 is a ‘1’. MS4 determines its assigned real resource as real base node 13 based on the rule that Nth ‘1’ in the virtual resource bitmap 1014 corresponds to the Nth ‘0’ in the resource availability bitmap 1012.
Type 2: For type 2 assignments, the mobile station processes virtual assignments by examining the bits in the resource availability bitmap 812, the virtual resource bitmap 814, and the offset field 816, if used. Consider the case where the bits in resource availability bitmap 812 and virtual resource bitmap 814 correspond to base nodes of their respective channel trees.
If a mobile station receives a type 2 virtual assignment via the assignment message, the mobile station determines its real assignment as follows. First, the mobile station determines which virtual base nodes make up the assigned virtual node. Denote the total number of virtual base nodes in the assignment as BNV and the number of the first virtual base node as FBNV, where the numbering of virtual base nodes begins with 1 (i.e. virtual base node 7 corresponds to FBNV=1). Second, the mobile station decodes remapping bitmap 810 and extracts the resource availability bitmap 812, virtual resource bitmap 814, and offset field 816, if used. Third, the mobile station determines the number of ‘1’s in the virtual resource bitmap and adds this to the value in offset field 816, if used. This value is denoted as V. Fourth, the mobile station determines the number of ‘0’s in the resource availability bitmap. This value is denoted as R. If R is greater than or equal to V+FBNV+BNV−1, the mobile station then determines its assigned real base nodes as the real base nodes corresponding to the V+FBNVth to V+FBNV+BNV−1th ‘0’s in the resource availability bitmap. If R is less than V+FBNV, the mobile station determines that is not assigned any real base nodes. If R is greater than or equal to V+FBNV and less than V+FBNV+BNV−1, the mobile station determines its assigned real base nodes as the real base nodes corresponding to the V+FBNV to Rth ‘0’ in the resource availability bitmap.
MS0: MS0 determines that virtual node 3 maps to virtual base nodes 7 and 8 (see
Type 3: For type 3 assignments, the mobile station processes virtual assignments by examining the bits in virtual resource bitmap 814 and offset field 816, if used. For type 3 assignments, resource availability bitmap 812 is not used. Consider the case where the bits in virtual resource bitmap 814 correspond to base nodes of a virtual channel tree.
If a mobile station receives a type 3 virtual assignment via the assignment message, the mobile station determines its real assignment as follows. First, the mobile station determines which virtual base nodes make up the assigned virtual node. Second, the mobile station decodes the remapping bitmap 810 and extracts the virtual resource bitmap 814 and the offset field 816, if used. Third, for each virtual base node in the assignment, the mobile station determines if the bit corresponding to the virtual base node in the virtual resource bitmap is set to ‘1’. If so, the mobile station maps the virtual base node to a real base node using the rule that the virtual base node corresponding to the Nth ‘1’ in the virtual resource bitmap is mapped to the (N+OS)th real base node, where OS is the value of the offset field 816, if used. Fourth, the mobile station determines its real assignment as the collection of real base nodes. Note that type 3 assignments are equivalent to type 1 assignments under the assumption that the resource availability bitmap for the type 1 assignment is all zeros.
MS0: MS0 determines that virtual node 1 maps to virtual base nodes 7, 8, 9, and 10. Based on the virtual resource bitmap, MS0 determines that virtual base nodes 7 and 9 are being mapped to real base nodes. MS0 determines the value of the offset field to be 3 (decimal 3 equals ‘11’). MS0 then determines that virtual base node 7 corresponds to the 1st ‘1’ in the virtual resource bitmap and is therefore mapped to the 4th (4=1+3) real base node. The 4th real base node is base node 10. Similarly, MS0 determines that virtual base node 9 maps to real base node 11.
MS1: MS1 determines that virtual node 2 maps to virtual base nodes 11, 12, 13, and 14. Based on the virtual resource bitmap, MS1 determines that virtual base node 12 is being mapped to a real base node. MS1 determines the value of the offset field to be 3 (decimal 3 equals ‘11’). MS1 then determines that virtual base node 12 corresponds to the 3rd ‘1’ in the virtual resource bitmap and is therefore mapped to the 6th (6=3+3) real base node. The 6th real base node is base node 12.
Type 4: For type 4 assignments, the mobile station processes virtual assignments by examining the bits in the resource availability bitmap 812 and the offset field 816, if used. Consider the case where the bits in the resource availability 812 correspond to base nodes of the real channel tree.
If a mobile station receives a type 4 virtual assignment via the assignment message, the mobile station determines its real assignment as follows. First, the mobile station determines which virtual base nodes make up the assigned virtual node. Denote the total number of virtual base nodes in the assignment as BNV and the number of the first virtual base node as FBNV, where the numbering of virtual base nodes begins with 1 (i.e. virtual base node 7 corresponds to FBNV=1). Second, the mobile station decodes the remapping bitmap 810 and extracts the resource availability bitmap 812 and the offset field 816, if used. Third, the mobile station determines the value of the offset field 816, if used. This value is denoted as OS. Fourth, the mobile station determines the number of ‘0’s in the resource availability bitmap. This value is denoted as R. If R is greater than or equal to OS+FBNV+BNV−1, the mobile station then determines its assigned real base nodes as the real base nodes corresponding to the OS+FBNVth to OS+FBNV+BNV−1th ‘0’s in the resource availability bitmap. If R is less than OS+FBNV, the mobile station determines that is not assigned any real base nodes and hence need not monitor the frame for traffic directed to that mobile station. If R is greater than or equal to OS+FBNV and less than OS+FBNV+BNV−1, the mobile station determines its assigned real base nodes as the real base nodes corresponding to the OS+FBNV to Rth ‘0’ in the resource availability bitmap.
MS0: MS0 determines that virtual node 4 maps to virtual base nodes 9 and 10. Based on this, MS0 determines that the number of virtual base nodes in its assignment, BNV, is 2 and that the first virtual base node in the assignment, FBNV, is 3. Since no offset field is present, MS0 determines that OS is equal to 0. MS0 determines that the number of ‘0’s in the resource availability bitmap 1312 is 4. Since R is greater than or equal to OS+FBNV+BNV−1, MS0 determines that is assigned the real base nodes corresponding to the 3rd (OS+FBNV) to 4th (OS+FBNV+BNV−1) ‘0’ in the resource availability bitmap, which are real base nodes 11 and 131316.
In some embodiments, resource availability bitmap 812 and virtual resource bitmap 814 are divided into multiple sections, wherein each section corresponds to a particular band in the frequency domain. For example, in a 5 MHz system, there could be 4 bands, where each band represents 1.25 MHz. If there are 32 resources in the 5 MHz system, then there are 8 resources in each of the 4 bands. In this embodiment, the assignment logic operates independently on each band (it can be thought of as having a resource availability bitmap 812 and a virtual resource bitmap 814 for each band which are then concatenated for transmission over the air). For example, for type 1 assignments, the virtual resource corresponding to the Nth ‘1’ in the virtual resource bitmap for the Bth band is mapped to the real resource corresponding to the Nth ‘0’ in the resource availability bitmap for the Bth band. In this way, the base station can employ frequency selective scheduling within the constraints of a remapping bitmap.
Using the four types of virtual assignments, real persistent assignments, and combinations of the above, a base station can control the QoS requirements of associated mobile stations in a wireless communication system. For virtual assignments, a base station can meet the QoS requirements of mobile stations by setting the values of the bits in resource availability bitmap 812 and virtual resource bitmap 814. As an example, consider a system where there are at least two services types having different QoS requirements. Consider that service type 1 has a QoS requirement which is delay intolerant and service type 2 has a QoS requirement which is delay tolerant. The base station can assign mobile stations having service 1 type real persistent assignments and can assign mobile stations having service type 2 virtual assignments. The base station then uses remapping bitmap 810 to indicate which virtual resources are being remapped to real resources in the current frame. Since remapping bitmap 810 is used, the number and location of the real resources devoted to mobile stations having service type 2 change from frame to frame and do not interfere with the resources used for transmitting packets to mobile stations having service type 1. In general, the base station can utilize real assignments and the four types of virtual assignments to meet different QoS requirements. This is particularly advantageous because the amount of overhead required for transmitting virtual resources is significantly lower than would be required for transmitting full assignment of real resources messages.
Additionally, using virtual assignments, the base station can control the number of resources that are used for each mobile station for each HARQ transmission by setting the values in the remapping bitmap 810. For example, in some embodiments, it is desirable to maintain the same number of resources for each HARQ transmission. The base station can guarantee this functionality by setting the values in the remapping bitmap 810.
Once a virtual resource is transformed into a real resource, the real resource assignment can be a persistent assignment as described above, a non persistent assignment, or an assignment that is valid for a fixed period of time. To illustrate assignments that are valid for a fixed period of time,
To facilitate this desired flexibility, a new assignment message parameter is defined to accompany the existing assignment message parameters.
Channel ID field 1512 typically addresses the nodes of a channel tree. This is desirable, since it reduces the number of bits required to make time-frequency assignments. However, in some embodiments, channel ID field 1512 is itself a bitmap, wherein each bit of channel ID 1512 field corresponds to one of the nodes in the channel tree. This increases the number of bits required to make time-frequency assignments and, at the same time, increases the flexibility of the time-frequency assignments themselves. In this way, a base station can assign time-frequency resources that do not correspond to a single node from a channel tree. For example, a base station can assign a mobile station disjoint time-frequency resources with one assignment message. For example, for the channel trees of
MIMO field 1517 is used to indicate the type of MIMO used by a base station, precoding scheme, antenna configuration, etc.
In some embodiments, real/virtual indication 1514 is indicated by setting the type header of the assignment message. In other embodiments, real/virtual indication 1514 is transmitted separately from the assignment message, for example in a higher layer message. In still other embodiments, real/virtual indication 1514 is conveyed to the mobile station by setting a subtreeID field in an assignment message (not shown in 1510). For example, subtreeID=‘0’ can be used to convey real assignments and subtreeID=‘1’ can be used to convey virtual assignments. It should now be clear to those skilled in the art that there is a variety of ways of communicating the parameters delineated in
Frames field 1516 is a new assignment message parameter. The length of frames field 1516 is preferably equal to the period of the desired timing. In the example of
For virtual assignments, when a bit in the frames field 1516 is set to ‘1’ for a particular frame, the mobile station decodes the remapping bitmap to determine its real assignment. When a bit in the frames field 1516 is set to ‘0’ for a particular frame, the mobile station assumes the same resource that was determined the last time remapping bitmap was processed. The frames field can also be applied to real assignments. For real assignments, when a bit in the frames field is set to ‘1’ for a particular frame, the real assignment is valid for that frame. When a bit in the frames bitmap is set to ‘0’ for a particular frame, the real assignment is not valid for that frame. Combining the functionality of the frames bitmap for real and virtual assignments, the base station may assign a mobile station a real resource for some frames and a virtual resource for other frames for transmission of the same packet. In this case, real assignments take precedence over virtual assignments.
For example, the base station may assign real resource 4 with the frames field equal to ‘1000’ and virtual resource 6 with frames field equal to ‘0100’ to the same mobile station for the transmission of a series of VoIP packets. In this case, the real resource 4 can be reserved for transmitting the first HARQ transmission of each VoIP packet. If the mobile station is unable to decode the packet after the first HARQ transmission, the mobile station decodes the remapping bitmap to transform its assigned virtual resource to a new real resource for HARQ transmission 2, 3, and 4.
In some embodiments, the frames field is omitted to minimize control channel overhead. For example, the base station and mobile station can always interpret virtual assignments as having a frames field of ‘1000’ even if a frames field is not transmitted as part of the assignment message. In other embodiments, the frames field is included in a higher layer message, which is transmitted from the base station to the mobile station separately from the assignment message. In other embodiments, a subset of the possible values of the frames field is encoded. For example, the frames field could be a one bit indication, with ‘1’ representing ‘1111’ and ‘0’ representing ‘1000’.
Although specific embodiments of the present invention have been described, it will be understood by those of skill in the art that there are other embodiments that are equivalent to the described embodiments. Accordingly, it is to be understood that the invention is not to be limited by the specific illustrated embodiments, but only by the scope of the appended claims.
This application claims priority to U.S. Provisional Patent Application No. 60/942,324 filed Jun. 15, 2007, entitled “Method and Apparatus for Sharing Resources in a Wireless System” which application is hereby incorporated herein by reference. This application is related to the following provisional U.S. patent applications, each of which is incorporated herein by reference: U.S. Provisional Patent Application No. 60/944,466 filed Jun. 15, 2007; U.S. Provisional Patent Application No. 60/944,469 filed Jun. 15, 2007; and U.S. Provisional Patent Application No. 60/944,477 filed Jun. 15, 2007. Further, this application is related to the following non-provisional patent applications, each of which is incorporated herein by reference: U.S. patent application Ser. No. ______, filed ______ (Attorney Docket No. HW07FW050); U.S. patent application Ser. No. ______, filed ______ (Attorney Docket No. HW07FW051); and U.S. patent application Ser. No. ______, filed ______ (Attorney Docket No. HW07FW052).
Number | Date | Country | |
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60944462 | Jun 2007 | US |