Patent Description:
OFDMA and single carrier FDMA have been selected as the downlink and uplink multiple access schemes for the E-UTRA air interface currently been studied in 3GPP (which is a standard based collaboration looking at the future evolution of third generation mobile telecommunication systems). Under the E-UTRA system, a base station which communicates with a number of user devices allocates the total amount of time/frequency resource (depending on bandwidth) among as many simultaneous users as possible, in order to enable efficient and fast link adaptation and to attain maximum multi-user diversity gain. The resource allocated to each user device is based on the instantaneous channel conditions between the user device and the base station and is informed through a control channel monitored by the user device.

<CIT> discloses bandwidth signalling in a multicarrier wireless communication system.

In order to support a large number of users devices, an efficient mechanism of resource signalling utilizing the least possible time/frequency resource is necessary.

And thus there is much desired in the art to provide a novel method for signalling resource allocation data in a communication system, communication node (or station), user devices therefore, a computer-readable program for operating the method and apparatus, devices and/or system.

Aspects of the invention are provided by the appended independent claims.

These and various other aspects of the invention will become apparent, from the following detailed description of modes which are given by way of example only and which are described with reference to the accompanying Figures.

<FIG> schematically illustrates a mobile (cellular) telecommunication system I in which users of mobile telephones <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> can communicate with other users (not shown) via a base station <NUM> and a telephone network <NUM>. In this mode, the base station <NUM> uses an orthogonal frequency division multiple access (OFDMA) technique in which the data to be transmitted to the mobile telephones <NUM> is modulated onto a plurality of sub-carriers. Different sub-carriers are allocated to each mobile telephone <NUM> depending on the supported bandwidth of the mobile telephone <NUM> and the amount of data to be sent to the mobile telephone <NUM>. In this mode the base station <NUM> also allocates the sub-carriers used to carry the data to the respective mobile telephones <NUM> in order to try to maintain a uniform distribution of the mobile telephones <NUM> operating across the base station's bandwidth. To achieve these goals, the base station <NUM> dynamically allocates sub-carriers for each mobile telephone <NUM> and signals the allocations for each time point (sub-frame) to each of the scheduled mobile telephones <NUM>.

<FIG> illustrates an example of the way in which the base station <NUM> can allocate sub-carriers within its supported bandwidth to different mobile telephones <NUM> having different supported bandwidths. In this mode, the base station <NUM> has a supported bandwidth of <NUM> of which <NUM> is used for data transmission. In <FIG>, MT represents mobile terminal.

In order that each of the mobile telephones <NUM> can be informed about the scheduling decision within each sub-band, each mobile telephone <NUM> requires a shared control channel within its camped frequency band. The information signalled within this control channel will include;.

Since the number of bits available in the control channel is limited, efficient methods are needed to transport the required information with the lowest number of bits. The invention relates to the way in which the resource allocation information can be signalled in an efficient manner to each of the mobile telephones <NUM>.

<FIG> is a block diagram illustrating the main components of the base station <NUM> used in this mode. As shown, the base station <NUM> includes a transceiver circuit <NUM> which is operable to transmit signals to and to receive signals from the mobile telephones <NUM> via one or more antennae <NUM> (using the above described sub-carriers) and which is operable to transmit signals to and to receive signals from the telephone network <NUM> via a network interface <NUM>. The operation of the transceiver circuit <NUM> is controlled by a controller <NUM> in accordance with software stored in memory <NUM>. The software includes, among other things, an operating system <NUM> and a resource allocation module <NUM>. The resource allocation module <NUM> is operable for allocating the sub-carriers used by the transceiver circuit <NUM> in its communications with the mobile telephones <NUM>. As shown in <FIG>, the resource allocation module <NUM> also includes an encoder module <NUM> which encodes the allocation into an efficient representation which is then communicated to the respective mobile telephones <NUM>.

In this mode, the base station <NUM> can use three different types of sub-carrier allocation:.

A first encoding technique that the encoder module <NUM> can use to encode the above described resource allocation information will now be described with reference to <FIG>. <FIG> schematically illustrates the way in which the <NUM> sub-carriers within a <NUM> sub-band of the base station's operating bandwidth are divided into a sequence of twelve chunks (labeled: <NUM>, <NUM>, <NUM>, <NUM>,. <NUM>), each comprising <NUM> sub-carriers. Information defining this arrangement of chunks may be stored as data within the memory of the base station <NUM> (and in the mobile telephones <NUM>) or it may be defined in the software or hardware circuits running therein. <FIG> also illustrates the way in which the encoder module <NUM> partitions, in this mode, the chunks of sub-carriers into a sequence of groups (in this case five groups), depending on the current sub-carrier allocation. In the example illustrated in <FIG>, the first group comprises chunks <NUM> and <NUM>; the second group comprises chunk <NUM>; the third group comprises chunks <NUM> to <NUM>; the fourth group comprises chunks <NUM> and <NUM>; and the fifth group comprises chunks <NUM> and <NUM>.

<FIG> also illustrates a resource allocation bit pattern <NUM> that is generated by the encoder module <NUM> and that defines this grouping of the chunks. As shown, the resource allocation bit pattern <NUM> includes one bit for each of the twelve chunks within the sub-band, which is set to a value of "<NUM>" when the corresponding chunk is the first chunk in a new group and otherwise it is set to a value of "<NUM>". As those skilled in the art will appreciate, the first bit of the twelve bit pattern <NUM> is redundant and does not need to be signalled (transmitted) because the first chunk within the sub-band will always be the first chunk within the first group.

<FIG> also illustrates a resource ID <NUM> which is provided for each of the defined groups. As shown, in this mode, the resource ID for a group identifies the group by its position within the sequence of groups. In particular, the resource IDs arc implicitly numbered from left to right corresponding to the associated group's position within the sequence of groups.

Each mobile telephone <NUM> is then informed of its allocation within each <NUM> sub-band by signalling the corresponding resource allocation bit pattern <NUM> and one of the resource IDs <NUM>. In this mode, the resource allocation bit patterns <NUM> are signalled to the mobile telephones <NUM> over a common signalling channel in each <NUM> sub-band and the resource ID(s) <NUM> for each mobile telephone <NUM> are individually signalled in its dedicated control channel. In this mode, each resource ID <NUM> is signalled as a <NUM> bit number leading to a maximum number of eight mobile telephones <NUM> that can be scheduled per <NUM> sub-band. Mobile telephones <NUM> with larger bandwidths can combine multiple <NUM> sub-bands and decode their total resource allocation from the resource allocation bit pattern <NUM> and the resource ID <NUM> from each sub-band.

As those skilled in the art will appreciate, the way in which the encoder module35 generates the above described resource allocation bit patterns <NUM> and resource IDs <NUM> will vary depending on how the sub-carriers have been allocated (i.e. using localised chunk allocation, distributed chunk allocation or distributed sub-carrier allocation). Examples of these different types of allocations will now be described with reference to <FIG>.

<FIG> illustrates one example where the sub-carriers have been allocated to the three mobile telephones <NUM> shown in <FIG> using a loealised chunk allocation. In particular, in this example, mobile telephone <NUM>-<NUM> has a supported bandwidth of <NUM> and is allocated chunks <NUM> and <NUM> in the first sub-band and chunks <NUM> and I in the second sub-band. Similarly, in this example, mobile telephone <NUM>-<NUM> has a supported bandwidth of <NUM> and is allocated chunk <NUM> in the first sub-band and chunks <NUM>, <NUM>, and <NUM> in the second sub-band. Note, the first sub-band means the first <NUM> sub-carriers (labeled <NUM>-<NUM>) in <FIG>, and the second sub-band means the second <NUM> sub-carriers (labeled <NUM>-<NUM>) in <FIG>. Finally, in this example, mobile telephone <NUM>-<NUM> has a supported bandwidth of <NUM> and is allocated chunks <NUM>, <NUM>, <NUM>, <NUM> and <NUM> within the first sub-band. <FIG> shows the two different resource bit patterns <NUM>-<NUM> and <NUM>-<NUM> and the corresponding resource IDs generated by the encoder module <NUM> for the two illustrated sub-bands. <FIG> also illustrates at the bottom of the figure the resource ID that is signalled to the respective mobile telephones <NUM>, As each mobile telephone <NUM> receives only <NUM> resource ID for each <NUM> sub-band that it occupies, its sub-carrier allocation is contiguous within each sub-band. However, a mobile telephone <NUM>, having a <NUM> supported bandwidth can be assigned resources in each of the <NUM> sub-bands it occupies, and these resources need not be contiguous with each other, as illustrated in <FIG> for mobile telephone <NUM>-<NUM>.

As discussed above, in this mode, it is assumed that at most eight mobile telephones <NUM> can be scheduled within each <NUM> sub-band at each time point (sub-frame). It may therefore appear that there is some redundancy in the twelve bit resource allocation bit pattern <NUM> (which could allow up to twelve resource IDs to be defined within each sub-band). However, even in the case that the maximum number of eight mobile telephones <NUM> are scheduled within a sub-band, it is still possible some sub-carriers are not used. For example, if eight mobile telephones <NUM> are allocated one chunk of sub-carriers and the remaining <NUM> unused chunks are not in a contiguous block, then up to twelve bits (or eleven if you ignore the first bit as discussed above) are still needed to define the partitioning of chunks to achieve the desired allocation.

<FIG> illustrates the way in which the same type of resource allocation bit pattern <NUM> and resource ID <NUM> can be used when a distributed chunk allocation scheme is employed. <FIG> illustrates the actual chunk allocation <NUM> for <NUM> different mobile telephones <NUM>, identified by the different shadings. In the illustrated example, one mobile telephone <NUM> is allocated <NUM> chunks (namely chunks <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM>); one mobile telephone is allocated <NUM> chunks (namely chunks <NUM>, <NUM> and <NUM>); and the other <NUM> mobile telephones <NUM> are each allocated <NUM> chunk of sub-carriers. In this mode, to facilitate the decoding of the resource allocation data in the mobile telephones <NUM>, the partitioning of the chunks is arranged in decreasing order in terms of the number of chunks per group. For the example shown in <FIG> this means that the group comprising <NUM> chunks is positioned first, followed by the group comprising <NUM> chunks, followed by the <NUM> remaining groups each comprising <NUM> chunk. As the resource IDs for these groups of chunks are numbered from left to right, this means that the mobile telephone <NUM> with the largest number of allocated chunks is given the smallest ID, the user with the second largest number of allocated chunks is given the next smallest ID etc. As will be apparent to those skilled in the art, the number of chunks allocated to each mobile telephone <NUM> needs to be a consideration in the number of chunks allocated to other mobile telephones <NUM> with a lower resource ID, in order to avoid resource collision during resource signalling decoding.

<FIG> schematically illustrates an example of a distributed sub-carrier allocation that may be employed. As with the example illustrated in <FIG>, in the example shown in <FIG>, there are five mobile telephones, with the first mobile telephone <NUM> been allocated sub-carriers <NUM>, <NUM>, <NUM>,. , <NUM>; with the second mobile telephone <NUM> been allocated sub-carriers <NUM>, <NUM>, <NUM>,. <NUM>; with the third mobile telephone <NUM> been allocated sub-carriers <NUM>, <NUM>,. <NUM>; with the fourth mobile telephone <NUM> been allocated sub-carriers <NUM>, <NUM>,. <NUM>; and with the fifth mobile telephone <NUM> been allocated sub-carriers <NUM>, <NUM>,. In this illustrated example, the spacing between the sub-carriers allocated to the first mobile telephone <NUM> is two, that between the sub-carriers allocated to the second mobile telephone <NUM> equals <NUM> and that between the sub-carriers allocated to the <NUM> remaining mobile telephones equals <NUM>. In this illustrative example, all the mobile telephones <NUM> occupy the <NUM> available chunks but with different sub-carrier spacing. The allocation is identical to the distributed chunk allocation repeated to span the entire S MHz bandwidth with the chunk bandwidth replaced by the sub25 carrier bandwidth. <FIG> illustrates the resulting resource allocation bit pattern <NUM> and resource IDs <NUM> for this sub-carrier allocation.

As those skilled in the art will appreciate, in order that the mobile telephones <NUM> can determine the correct sub-carrier allocation, they must be informed of the type of sub-carrier allocation that has been made (i.e. localised chunk allocation, distributed chunk allocation or distributed sub-carrier allocation). This information is signalled to all of the mobile telephones <NUM> using the following two bit allocation type pattern:.

As will be described in more detail below, the mobile telephones <NUM> use this allocation type bit pattern to identify how they should interpret the group of chunks that has been assigned to it, using the resource allocation bit pattern <NUM> and the resource ID <NUM>.

<FIG> is a flow chart illustrating the main processing steps carried out by the encoder module <NUM> to determine the above described resource allocation bit patterns <NUM> and resource IDs <NUM> for the different mobile telephones <NUM> scheduled for a current time point. As shown, in step s1, the encoder module <NUM> receives the current sub-carrier allocation, which includes details as to whether or not the allocation is in accordance with the localised chunk allocation scheme, distributed chunk allocation scheme or distributed sub-carrier allocation scheme. In step s3, the encoder module <NUM> partitions the chunks of sub-carriers in each of the base station's four <NUM> sub-bands into groups, based on the received sub-carrier allocation. As those skilled in the art will appreciate the processing performed in step s3 will depend on the type of sub-carrier allocation that has been performed. In step s5, the encoder module <NUM> generates the above described resource allocation bit pattern <NUM> for each <NUM> sub-band, that represents the partition of chunks in that sub-band. Then, in step s7, the encoder module <NUM> generates a resource ID for each group of chunks in each sub-band for signalling to the corresponding mobile telephone <NUM>.

After the resource IDs <NUM> have been generated for the groups of chunks in each <NUM> sub-band, the processing proceeds to step s9 where the encoder module <NUM> signals (transmits) the generated resource allocation bit patterns <NUM> to all of the mobile telephones <NUM>. In particular, in this step, the encoder module <NUM> causes the transceiver circuit <NUM> to signal, within a common signalling channel in each <NUM> sub-band, the resource allocation bit pattern <NUM> representing the partitioning of the chunks within that sub-band. The mobile telephones <NUM> will therefore be able to receive the resource allocation bit patterns <NUM> for all the sub-bands in which they operate. For example, if mobile telephones <NUM>-<NUM> and <NUM>-<NUM> have an operating bandwidth of <NUM> and mobile telephone <NUM>-<NUM> has an operating bandwidth of <NUM>, then mobile telephones <NUM>-<NUM> and <NUM>-<NUM> will receive two resource allocation bit patterns <NUM> within their common signalling channels and mobile telephone <NUM>-<NUM> will receive one resource bit pattern <NUM> within its common signalling channel. The above described two bit resource allocation type pattern is also transmitted with each resource allocation bit pattern <NUM> in step s9. After step s9, the processing proceeds to step si <NUM> where the encoder module <NUM> signals the respective resource IDs <NUM> to each mobile telephone <NUM> within the mobile telephone's dedicated signalling channel in each <NUM> sub-band.

Therefore, with the first encoding technique for each <NUM> sub-band, a total of <NUM> common channel bits are signalled (<NUM> if the first bit of the resource allocation pattern is not signalled) and three resource ID bits for each user device are signalled.

<FIG> schematically illustrates the main components of each of the mobile telephones <NUM> shown in <FIG>. As shown, the mobile telephones <NUM> include a transceiver circuit <NUM> which is operable to transmit signals to and to receive signals from the base station <NUM> via one or more antennae <NUM>. As shown, the mobile telephone <NUM> also includes a controller <NUM> which controls the operation of the mobile telephone <NUM> and which is connected to the transceiver circuit <NUM> and to a loudspeaker <NUM>, a microphone <NUM>, a display <NUM>, and a keypad <NUM>. The controller <NUM> operates in accordance with software instructions stored within memory <NUM>. As shown, these software instructions include, among other things, an operating system <NUM> and a communications module <NUM>. In this mode, the communications module <NUM> includes a decoder module <NUM> which is operable to decode the resource allocation data signalled from the base station <NUM> to determine that mobile telephone's sub-carrier allocation for the current time point.

The way which the decoder module <NUM> decodes the resource allocation data received from the base station <NUM> will now be described with reference to the flowchart shown in <FIG>. As shown, in step s2 <NUM>, the decoder module <NUM> receives the resource allocation bit pattern <NUM> and the associated two bit allocation type pattern from each received common signalling channel. As will be apparent from the above discussion, the number of resource allocation bit patterns <NUM> and the number of allocation type patterns received depends on the supported bandwidth of the mobile telephone <NUM>. In step s23, the decoder module <NUM> receives the resource ID(s) <NUM> from its dedicated signalling channel(s). The number of resource IDs <NUM> received also depends on the supported bandwidth of the mobile telephone <NUM>. Then in step s25, the decoder module <NUM> identifies, for each supported <NUM> sub-band, the start and end chunks of the group of chunks associated with the resource ID <NUM> received for that sub-band. The decoder module <NUM> identifies these start and end chunks using the corresponding resource allocation bit pattern <NUM> received for that sub-band. For example, if the received resource ID <NUM> is the binary value "<NUM>" corresponding to the resource ID "<NUM>", then the decoder module <NUM> processes the corresponding resource allocation bit pattern <NUM> to identify the bit positions of the second and third "<NUM>" counting from the left (and ignoring the first bit within the resource allocation bit pattern <NUM> if it includes <NUM> bits as the first bit always corresponds to the start of the first group). The bit position of this second "<NUM>" identifies the beginning of the group having resource ID "<NUM>" and the bit position of the third "<NUM>" identifies the chunk that is at the start of the next group within the sequence of groups, from which the decoder module <NUM> can determine the end chunk of the group having resource ID "<NUM>". In the example illustrated in <FIG> for the first sub-band, the second "<NUM>" in the resource bit allocation pattern <NUM> (ignoring the first bit) is the fourth bit from the left hand end and the third "<NUM>" within the bit pattern <NUM><NUM> is the ninth bit from the left hand end. As can be seen from <FIG>, this means that the group of chunks corresponding to the received resource ID of "<NUM>" comprises chunks <NUM> to <NUM> within that <NUM> sub-band.

Once the start and end chunks of the group associated with the received resource ID <NUM> have been determined, the processing proceeds to s27, where the decoder module <NUM> uses the received two bit allocation type pattern to determine if the allocation is a localised chunk allocation. If it is, then the processing proceeds to step s29 where the decoder module <NUM> determines that the allocated sub-carriers correspond to the continuous set of sub-carriers within and between the identified start and end chunks. For the above example this will result in the decoder module <NUM> allocating the sub-carriers within chunks <NUM> to <NUM> (inclusive), for communications with the base station <NUM>.

If at step s27, the decoder module <NUM> determines that the two bit allocation type pattern does not correspond to a localised chunk allocation, then processing proceeds to step s3 I where the decoder module <NUM> determines if the two bit allocation type pattern corresponds to a distributed chunk allocation. If it does, then the processing proceeds to step s33 where the decoder module <NUM> uses the identified start and end chunks to determine the chunk spacing by dividing the total number of chunks within the sub-band by the number of chunks between the identified start and end chunks. For example, for the distributed chunk allocation illustrated in <FIG> and where the received resource ID <NUM> is "<NUM>", the total number of chunks within the sub-band equals <NUM> and the number of chunks between the identified start and end chunks is <NUM>. Therefore, <NUM> chunks are allocated within this sub-band that are spaced apart by <NUM> (<NUM>/<NUM> = <NUM>) chunks. The position of the first of these chunks within the sub-band depends on the sub-carrier allocation for other scheduled mobile telephones <NUM> within that sub-band. Consequently, when distributed chunk allocation has been selected, the decoder module <NUM> also considers the chunk allocation for the other mobile telephones <NUM> scheduled at that time. The decoder module <NUM> does this by identifying the positions of all of the "<NUM>" within the resource allocation bit pattern <NUM> to determine the total number of chunks allocated in other groups. For the allocation shown in <FIG>, the decoder module will identify that the group corresponding to resource ID "<NUM>" has <NUM> chunks; that the group corresponding to resource ID "<NUM>" has <NUM> chunks and that the remaining <NUM> groups corresponding to resource IDs "<NUM>", "<NUM>" and "<NUM>" each have <NUM> chunk. From this information, the decoder module <NUM> determines that the chunks associated with resource ID "<NUM>" will be spaced apart by <NUM> chunks.

In this mode, the distributed chunk allocation scheme is arranged so that the first chunk within the sub-band is always allocated to the first chunk allocated to resource ID "<NUM>". Therefore, for the above example, the allocated chunks for resource ID "<NUM>" will be chunks <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>. The decoder module <NUM> then considers the allocated chunks for resource "<NUM>". As discussed above, the chunk spacing for resource ID "<NUM>" is <NUM>. The decoder module <NUM> then assigns the first chunk for resource ID "<NUM>" as being the first available chunk after the chunks for resource ID "<NUM>" have been allocated. In this example, the first unallocated chunk is chunk <NUM> and therefore, the chunks allocated to resource ID "<NUM>" will be chunks <NUM>, <NUM> and <NUM>. In a similar manner, the first chunk that is available for allocation for resource ID "<NUM>" is chunk <NUM> etc..

As those skilled in the art will appreciate, as the groups of chunks have been ordered so that the largest groups have the lowest resource IDs <NUM> than its own, in this mode, the mobile telephone <NUM> only needs to consider the chunk allocations for the groups with a lower resource ID <NUM>, when determining the position of its first allocated chunk in the sub-band.

If at step s31, the decoder module <NUM> determines that the two bit allocation type pattern does not corresponded to a distributed chunk allocation, then the decoder module <NUM> determines that the allocation corresponds to a distributed sub-carrier allocation as illustrated in <FIG>. In this case the processing proceeds to step s35, where the decoder module <NUM> determines the number of sub-carriers assigned to the mobile telephone <NUM> by multiplying the number of chunks in the assigned group by the number of sub-carriers in each chunk (i.e. by twenty five). The decoder module <NUM> also calculates the spacing between the sub-carriers by dividing the total number of chunks in the sub-band by the number of chunks in the allocated group. The position of the first sub-carrier is then determined to be the first sub-carrier available after the sub-carriers have been assigned for groups associated with resource IDs having lower values, in a similar way to the way in which the starting chunk was determined in the distributed chunk allocation processing described above.

After the decoder module <NUM> has determined its sub-carrier allocation (either in step s29, step s33 or step s35), the decoder module <NUM> sends appropriate control signals to the transceiver circuit <NUM> to control the reception of data using the identified sub-carriers. The processing then ends.

A second encoding technique that the encoder module <NUM> within the base station <NUM> can use to encode the above described resource allocation information will now be described with reference to <FIG>, <FIG>. As illustrated in <FIG>, the <NUM> operating bandwidth of the base station <NUM> can be divided into sub-bands of different sizes, with the smallest sub-band corresponding to a bandwidth of <NUM>. The number of chunks available for each sub-band is given in the table below:.

In this second encoding technique, a triangular code tree is used with the number of chunks available for a particular bandwidth equal to the number of leaf nodes at the base of the code tree. For the example of a <NUM> sub-band shown in <FIG>, which has <NUM> chunks, the corresponding code tree is illustrated in <FIG>. As shown, the code tree <NUM> is formed from a tree of nodes having a depth of N nodes corresponding to the number of chunks within the sub-band and having N leaf nodes in the bottom row of the code tree <NUM>. In this example, there are six chunks and therefore, the tree has a depth of <NUM>. The total number of nodes within the tree equals N(N+<NUM>)/<NUM>. A node number from this tree can therefore be signalled using ceil(log<NUM>(N*(N+<NUM>)/<NUM>)) number of bits. The exact number of bits required for each bandwidth is shown in the table below:.

In this mode, the node numbering is designed to optimise the number of signalling bits required to signal a particular resource allocation. In the example illustrated in the <FIG>, for a <NUM> bandwidth, a five bit number is signalled to uniquely determine the starting chunk and the number of consecutive chunks allocated (which identifies the end chunk). In the general case where there are N chunks within the sub-band, the starting chunk (O) and the number of consecutive chunks (P) that are allocated can be signalled as an unsigned integer x as follows:
<IMG>
where <MAT>is the ceiling function, ie the smallest integer not less than r. At the receiver, the values of P and O can be then be extracted as follows:
<IMG>
where <MAT> is the floor function, ie the largest integer not greater than r.

One advantage with this encoding technique is that no look up table (or code tree structure) is required to carry out the encoding or decoding. Further, the division by N performed by the receiver can also be implemented by a simple multiplication and shift operation.

For localised chunk allocation, each mobile telephone <NUM> will be signalled a node number, which maps to a set of leaf chunks. As an example, if one mobile telephone <NUM> is allocated chunks <NUM> and <NUM>, another mobile telephone is allocated chunks <NUM>, <NUM> and <NUM> and a third mobile telephone <NUM> is allocated chunk <NUM> from the <NUM> bandwidth illustrated in <FIG>, then the first mobile telephone <NUM> will be signalled the value <NUM>, the second mobile telephone <NUM> will be signalled the value <NUM>, and the third mobile telephone <NUM> will be signalled the value <NUM>, These values are preferably determined using the first equation given above. Alternatively, these node numbers can be determined from the tree structure <NUM> by identifying the root node that is common to the allocated chunks. For example, for the first mobile telephone <NUM>, where the allocated chunks correspond to chunks <NUM> and <NUM>, the root node that is common to these nodes is the node numbered <NUM>. Similarly, for the second mobile telephone <NUM>, which has been allocated chunks <NUM>, <NUM> and <NUM>, the node which is the common root for the starting chunk <NUM> and the end chunk <NUM> is the node numbered <NUM>. Finally, for the third mobile telephone that has been allocated chunk <NUM>, since there is only <NUM> chunk, there is no common node and therefore the node number that is signalled corresponds to the allocated chunk number (i.e. <NUM>).

In the case of a distributed chunk allocation for the same bandwidth, the same equations can be used to signal the chunks that have been allocated. For example, if a mobile telephone <NUM> is allocated chunks <NUM> and <NUM>, then the number <NUM> is signalled together with a distributed chunk allocation indicator. At the mobile telephone, the P and O values are decoded in the same manner as discussed above, however, their interpretation is different. In particular, with distributed chunk allocation, the value of P denotes the chunk spacing and the value of O denotes the first chunk in the distributed allocation.

Multiplexing of distributed chunk allocation and localised chunk allocation at the same time point is also easily supported using this encoding method. For example, one mobile telephone <NUM> may allocated a localised allocation and signalled the value <NUM>, which maps to chunks <NUM>, <NUM>, and <NUM> whilst another mobile telephone is allocated a distributed chunk allocation and signalled the value <NUM>, which maps to chunks <NUM> and <NUM>.

Distributed sub-carrier allocation with different spacing for different mobile telephones can also be supported using the above encoding scheme. In this case, the values of O and P are also interpreted in a different way. In this case, as distributed sub-carrier allocation has been selected, the value of O will identify the allocated sub-carrier offset and the value of P will define the spacing between the sub-carriers. For example, if a mobile telephone <NUM> is signalled the value <NUM> and an indication that distributed sub-carrier allocation has been made, then the sub-carrier offset will be <NUM> and the sub-carrier spacing will be <NUM>. Similarly, a mobile telephone <NUM> signalled the value <NUM> and a distributed sub-carrier indicator will assume a sub-carrier offset of <NUM> and a sub-carrier spacing of <NUM>. As those skilled in the art will appreciate multiplexing of localised chunk and distributed sub-carrier is not possible with this encoding technique.

Although the above examples illustrate the situation for a <NUM> sub-band, this is for ease of illustration only. Resource allocation within the base station's total bandwidth can be accomplished in units of the downlink reception capability of the different mobile telephones <NUM>. For example, if all mobile telephones <NUM> can receive at least <NUM>, then the resource allocation at the base station <NUM> can be done in units of <NUM>. Larger bandwidth mobile telephones <NUM> can then combine control channels over multiple <NUM> bands to decide their resource allocation.

A number of detailed modes have been described above. As those skilled in the art will appreciate, a number of modifications and alternatives can be made to the above modes whilst still benefiting from the inventions embodied therein. By way of illustration only a number of these alternatives and modifications will now be described.

In the above modes, a mobile telephone based telecommunication system was described in which the above described signalling techniques were employed. As those skilled in the art will appreciate, the signalling of such resource allocation data can be employed in any communication system that uses a plurality of sub-carriers. In particular, the signalling techniques described above can be used in wire or wireless based communications either using electromagnetic signals or acoustic signals to carry the data. In the general case, the base station would be replaced by a communication node which communicates with a number of different user devices. User devices may include, for example, personal digital assistants, laptop computers, web browsers, etc..

In the above modes, the base station was assumed to have an operating bandwidth of <NUM> (which was divided into a number of sub-bands) and the chunks of carrier frequencies were defined to comprise <NUM> sub-carriers each. As those skilled in the art will appreciate, the invention is not limited to this particular size of bandwidth or chunk size or to the size of the sub-bands described.

In the first encoding technique described above, the base station partitioned the chunks within the sub-band into a number of groups. The beginning and end of these groups were then identified by bits within a resource allocation bit pattern. In the example, a "<NUM>" within this bit pattern represented the beginning of a new group. As those skilled in the art will appreciate, other encoding schemes could be used. For example, a "<NUM>" could be used to define the start of each group. Alternatively, a change in bit value may be used to define the start of each group.

In the first encoding technique described above, the resource ID allocated for each sub-band was transmitted to each mobile telephone over a dedicated signalling channel. As those skilled in the art will appreciate, this resource ID information may instead be signalled within the common signalling channel. In this case, the user devices ID corresponding to each resource ID will be signalled within the common signalling channel, so that each user device can identify the resource ID allocated to it.

In the first encoding technique described above, the base station and mobile telephone implicitly numbered the groups and the chunks from left to right within the sub-band. As those skilled in the art will appreciate, this is not essential. The numbering of the groups and chunks may be performed in other ways such as from right to left. Provided both the base station <NUM> and the mobile telephones <NUM> know the numbering scheme in advance, the above encoding can be carried out.

In the above encoding schemes, the base station <NUM> was able to allocate sub-carriers using a number of different allocation techniques. As those skilled in the art will appreciate, one or more of these allocation techniques may be dispensed with. Further, if only one allocation technique is used, then there is no need to signal a separate allocation type bit pattern.

In the second encoding technique described above, a mapping was defined between the chunks and a unique number which represented the combination of a start chunk and an end chunk within a sequence of chunks allocated to the user. As those skilled in the art will appreciate, this mapping may be defined in any appropriate way, such as using an equation or using a lookup table. The use of an equation is preferred as it removes the need to store a lookup table both in the base station <NUM> and in each of the mobile telephones <NUM>.

In the above modes, a number of software modules were described. As those skilled will appreciate, the software modules may be provided in compiled or un-compiled form and may be supplied to the base station or to the mobile telephone as a signal over a computer network, or on a recording medium. Further, the functionality performed by part or all of this software may be performed using one or more dedicated hardware circuits. However, the use of software modules is preferred as it facilitates the updating of base station <NUM> and the mobile telephones <NUM> in order to update their functionalities.

It should be noted that other objects, features and aspects of the present invention will become apparent in the entire disclosure and that modifications may be done without departing from the scope of the present invention as disclosed herein and claimed as appended herewith.

Claim 1:
A method in a user device (<NUM>) configured to communicate with a communication node (<NUM>), the method comprising:
receiving, from the communication node (<NUM>), downlink control information including information indicating a resource indication value for indicating a resource allocation, wherein the resource indication value is defined by either a first expression or a second expression, wherein:
the first expression is N(P-<NUM>)+O, and
the second expression is N(N-P+<NUM>)+(N-<NUM>-O),
where N is a number of resource blocks in a bandwidth, O is a starting resource block number and P is a length in terms of number of contiguously allocated resource blocks; and
interpreting the information indicating the resource indication value based on the downlink control information.