US 20040248582 A1 Abstract This invention relates to a method for rate matching between at least two transport channels included within a composite channel. An object of this method is to minimize the number of the DTX symbols inserted the composite channel. This method comprises a rate matching step for each transport channel (i), a rate matching ratio (RF
_{i}) being applied to each transport channel. The inventive method comprises a step (301) for defining, for said composite channel, a ordered list of transport channels, a step (302) for determining at least two so-called global intervals for said ordered list of transport channels, and a step (303) for assigning a scale factor (LF) to each determined global interval. Claims(11) 1-10. (Canceled) 11. A method for configuring at least one transport channel of a Code Division Multiple Access type telecommunication system, said Code Division Multiple Access type telecommunication system implementing a phase of communicating data conveyed by said at least one transport channel, said phase of communicating data comprising at least one rate matching step for each of said at least one transport channel, each of said rate matching steps executing a transformation of an input block of an initial size into an output block of a final size by puncturing or repeating at least one data of said input block according to a rate matching ratio, said rate matching ratio being applied to each of said at least one transport channel, said rate matching ratio being equal to a product of a rate matching factor and a scale factor, said rate matching factor being specific to said transport channel, each of said at least one transport channel being transmitted for at least one associated transmission time interval, each of said transmission time intervals having a duration specific to each of said at least one transport channel, said method comprising successive steps of:
defining a list of at least one transport channel ordered in descending order of the duration of the at least one corresponding transmission time interval, said ordered list being able to include at least one transport channel not transporting any data for at least one associated transmission time interval, determining at least two so-called global intervals for said ordered list, said determined global intervals following each other in time, each of said determined global intervals coinciding:
either with the transmission time interval associated with the first transport channel of said ordered list transporting data for said associated transmission time interval,
or, in case none of said at least one transport channel of said ordered list is transporting any data, with the smallest transmission time interval,
assigning a scale factor to each of said determined global intervals, said scale factor being common to said at least one transport channel, said scale factor being constant for the duration of each corresponding determined global interval.
12. The method according to 13. The method according to defining, for said composite channel, a list of at least two transport channels ordered in descending order of the duration of their respective transmission time intervals, said ordered list being able to include at least one transport channel not transporting any data for at least one associated transmission time interval, determining, for said composite channel, at least two global intervals for said ordered list, said determined global intervals following each other in time, each of said determined global intervals coinciding:
either with the transmission time interval associated with the first transport channel of said ordered list transporting data for said associated transmission time interval,
or, in case none of said at least two transport channels of said ordered list is transporting any data, with the smallest transmission time interval,
assigning a scale factor to each of said determined global intervals, said scale factor being common to said at least two transport channels, said scale factor being constant for the duration of each corresponding determined global interval. 14. The method according to N
_{data }being a maximum data rate supplied to said composite channel by said at least one physical channel; k being a type of coded blocks;
I(k) being a transport channel generating said type k of coded blocks;
X
_{k }being the number of data of said transport channel generating said type k of coded blocks before said rate matching step ; F
_{I(k) }being a ratio between the duration of said transmission time interval of said transport channel generating said type k of coded blocks and the duration of a common period, said duration of said common period being a common divisor of the duration of each of the transmission time intervals associated with said plurality of transport channels included within said composite channel; MSB(j) being the plurality of coded block types for a transport format combination j; and
TFCSG(p) being a part of the plurality of transport format combinations, for a part p of a combination of transport formats for some considered transport channels among said plurality of transport channels included within said composite channel, including, for each transport format combination, the same transport formats for said considered transport channels and all the corresponding transport formats for the other transport channels having transmission time intervals with durations lower than or equal to the duration of said determined global interval.
15. The method according to 14, wherein a plurality of scale factor values are determined for a plurality of determined global intervals, said method further comprising the successive steps of:
defining a sub-list of at least one transport channel, said sub-list including a part of the plurality of the transport channels of said ordered list from the first transport channel to a given transport channel, said sub-list being ordered in descending order of the duration of the transmission time interval associated with each of said at least one transport channel of said sub-list, and
substituting said sub-list to said ordered list, in order to reduce, for said composite channel, the number of scale factor values to be determined for said plurality of said determined global intervals with respect to the number of the scale factor values to be determined with the defined ordered list.
16. The method according to any of 17. The method according to 18. A method for configuring at least one transport channel of a Code Division Multiple Access type telecommunication system implemented by a base station, said Code Division Multiple Access type telecommunication system comprising at least one base station and at least one mobile station, said Code Division Multiple Access type telecommunication system implementing a phase of communicating data conveyed by said at least one transport channel, said phase of communicating data comprising at least one rate matching step for each of said at least one transport channel, each of said rate matching steps executing a transformation of an input block of an initial size into an output block of a final size by puncturing or repeating at least one data of said input block according to a rate matching ratio, said rate matching ratio being applied to each of said at least one transport channel, said rate matching ratio being equal to a product of a rate matching factor and a scale factor, said rate matching factor being specific to said transport channel, each of said at least one transport channel being transmitted for at least one associated transmission time interval, each of said transmission time intervals having a duration specific to each of said at least one transport channel, said method comprising successive steps of:
defining a list of at least one transport channel ordered in descending order of the duration of the at least one corresponding transmission time interval, said ordered list being able to include at least one transport channel not transporting any data for at least one associated transmission time interval, determining at least two so-called global intervals for said ordered list, said determined global intervals following each other in time, each of said determined global intervals coinciding:
either with the transmission time interval associated with the first transport channel of said ordered list transporting data for said associated transmission time interval,
or, in case none of said at least one transport channel of said ordered list is transporting any data, with the smallest transmission time interval,
assigning a scale factor to each of said determined global intervals, said scale factor being common to said at least one transport channel, said scale factor being constant for the duration of each corresponding determined global interval. 19. A Code Division Multiple Access type telecommunication system comprising at least one sending entity and at least one receiving entity, said Code Division Multiple Access type telecommunication system implementing a phase of communicating data conveyed by said at least one transport channel, said phase of communicating data comprising at least one rate matching step for each of said at least one transport channel, each of said rate matching steps executing a transformation of an input block of an initial size into an output block of a final size by puncturing or repeating at least one data of said input block according to a rate matching ratio, said rate matching ratio being applied to each of said at least one transport channel, said rate matching ratio being equal to a product of a rate matching factor and a scale factor, said rate matching factor being specific to said transport channel, each of said at least one transport channel being transmitted for at least one associated transmission time interval, each of said transmission time intervals having a duration specific to each of said at least one transport channel, said Code Division Multiple Access type telecommunication system comprising:
means for defining a list of at least one transport channel ordered in descending order of the duration of the at least one corresponding transmission time interval, said ordered list being able to include at least one transport channel not transporting any data for at least one associated transmission time interval, means for determining at least two so-called global intervals for said ordered list, said determined global intervals following each other in time, each of said determined global intervals coinciding:
or, in case none of said at least one transport channel of said ordered list is transporting any data, with the smallest transmission time interval,
means for assigning a scale factor to each of said determined global intervals, said scale factor being common to said at least one transport channel, said scale factor being constant for the duration of each corresponding determined global interval. 20. A base station, wherein said base station is comprised within a Code Division Multiple Access type telecommunication system according to Description [0001] This invention relates to a method for rate matching between at least two transport channels included within a composite channel, said method comprising at least one rate matching step for each transport channel, a rate matching ratio being applied to each transport channel, said rate matching ratio being equal to the product of a rate matching factor specific to said transport channel and a scale factor, said scale factor being common to the set of said transport channels of said composite channel, each of said transport channels being transmitted for at least one associated transmission time interval, each of said transmission time intervals having a duration specific to each of said transport channels, at least two of said transport channels having transmission time intervals of distinct duration. This invention is implemented in particular in the field of third generation telecommunication systems for mobiles. [0002] The 3rd Generation Partnership Project is an organization whose purpose is the standardization of a third generation telecommunication system for mobiles. The technology considered for such systems is the CDMA (Code Division Multiple Access) technology. One of the fundamental aspects distinguishing third generation systems from second generation ones is that, in addition to making more efficient use of the radio spectrum, they provide very good service flexibility. [0003] One of the issues of third generation mobile radio systems is to efficiently multiplex at the radio interface services not having the same requirements in terms of quality of service (QoS). Such differences in quality of service imply in particular using respective transport channels with different channel coding and interleaving and also require different bit error rates (BER) for each transport channel. For a given channel coding, the bit error rate is sufficiently low when all coded symbols have a sufficiently high Eb/I ratio. The Eb/I ratio is the ratio of the average energy of each coded bit (Eb), and the average interference energy (I). In addition, the relationship providing the bit error rate obtained depending on the incoming Eb/I ratio depends on the coding. [0004] It is recalled that the term symbol designates a piece of information that can have a finite number of values within a given alphabet. E.g., a symbol that can have two values is the same as a bit in terms of information. [0005] Consequently, the different services, not having the same quality of service, do not have the same requirements in terms of the Eb/I ratio. And yet, in a CDMA-type system, the system's capacity is limited by the interference level. Thus, an increase in energy per bit of coded symbols for one user (Eb) contributes to an increase in interference (I) for the other users. Therefore, the Eb/I ratio must be set precisely for each service in order to limit interference generated by this service. An Eb/I ratio balancing operation between the different services is then required. [0006] Therefore, it is envisaged to balance the Eb/I ratio among the different services. This balancing is done at transmission by rate matching of the coded transport channels transporting different services. Rate matching either consists in repeating symbols (rate matching ratio greater than one), or in puncturing symbols (rate matching ratio less than one). When rate matching is done, at transmission, by repeating certain symbols, then, for each repeated symbol, a set is formed grouping the positions where the symbol is located after repetition. [0007] Also, when rate matching is done, at transmission, by puncturing certain symbols, then, a set is formed grouping the positions where a symbol has been removed. [0008] When the transport channels rate matched by repetition or puncturing are received, a reverse operation, called de-rate matching, is performed. In case the transport channels are rate matched by repetition, the amplitudes of the repeated symbols received are added, in order to form, after de-rate matching, a single symbol. The amplitude of this single symbol is then equal to the sum of the amplitudes of the repeated symbols. [0009] In case the transport channels are rate matched by puncturing, zero amplitude symbols are inserted, after de-rate matching, among the symbols received so that after this insertion, they are located at the symbol positions indicated by the set. [0010] The same rate matching ratio applies to sending and receiving. Upon transmission, the rate matching ratio, except for rounding, is equal to the ratio of the rate matched block size to the corresponding block size to be rate matched. Upon receipt, the rate matching ratio, except for rounding, is equal to the ratio of the block size before de-rate matching to the corresponding block size obtained after de-rate matching. [0011] In the OSI (Open System Interconnection) model of the ISO (International Standardization Organization), a telecommunication equipment is modeled by a layer model constituting a protocol stack wherein each layer is a protocol providing a service to the higher level layer. In the system of the 3GPP group, the service provided by the level [0012] Described hereafter is the known data processing technique in the downlink of the system of the 3GPP group with reference to FIGS. 1 and 2. [0013] The transmission chain of a composite channel for a downlink of a third generation telecommunication system, such as defined by the 3GPP group, is shown in FIG. 1.; [0014] For each transport channel with its own quality of service, referenced as [0015] An example of transport channels A, B, C, and D, respectively having TTI interval duration of 80 ms, 40 ms, 20 ms and 10 ms is shown in FIG. 2. In this figure, the transport block set received by each transport channel is represented by a bar chart bar. The length of bar chart bar represents a TTI interval of the associated transport channel and its surface corresponds to the payload of the transport block set. The horizontal dotted lines in the bar chart bars define the transport block(s) included in each transport block set. Thus, transport channel A receives, during a first transmission time interval, a first transport block set marked A [0016] It should be noted that a TTI interval of a given transport channel cannot overlap two TTI intervals of another-transport channel. This is enabled due to the possible duration of TTI intervals increasing geometrically (10 ms, 20 ms, 40 ms and 80 ms). In addition, the transport format designates information, representing the number of transport blocks contained in the transport block set received by a transport channel and their respective sizes. For a given transport channel, there is a finite set of possible transport formats one of which is selected at each TTI interval depending on the requirements of the higher level layers. For a constant bit rate transport channel, this set only comprises one element. In this figure, the transport format of the transport channels is indicated by a number. Thus, for the first TTI of transport channel A extending over frames [0017] In addition, a radio frame designates a periodical time interval numbered and synchronized according to a signal broadcast by the network. The duration of a radio frame is 10 ms in the system of the 3GPP group. In the example of FIG. 2, transport channel A has a first transport format for set A [0018] Hereafter, the expression transport format combination designates information defining, for each multiplexing frame, the transport formats associated with each transport channel, the term multiplexing frame designating a data block generated periodically, e.g. at each radio frame, and comprising data from the set of transport channels. Thus, with reference to FIG. 2, the time intervals associated with multiplexing frames being radio frames, the transport format combination for the radio frame numbered [0019] Referring again to FIG. 1, each transport channel, referenced as [0020] The coded transport channel is first rate matched in the step referenced as [0021] or
[0022] each of them being transmitted in one multiplexing frame. It should be noted that ┌x┐ et └x┘ respectively designate the smallest integer greater than or equal to x and the largest integer less than or equal to x. The multiplexing frame is the data block produced by step [0023] When at least one transport channel is in a flexible position, DTX symbols are inserted in a subsequent step referenced as [0024] The capacity of a physical channel being limited, it may happen that the number of physical channels required for conveying this composite channel is greater than one. In this case, a step [0025] The data segments obtained are then interleaved in ha step referenced as [0026] It is recalled that DTX symbols are dummy symbols that carry no information at all, and subsequently to step [0027] As mentioned above, the rate matching step [0028] During the rate matching step [0029] After the rate matching step [0030] Balancing the Eb/I ratio only establishes the proportion between the respective rate matching ratios RF [0031] and its upper limit is established by the available bit rate N [0032] In addition, the rate matching ratio RF [0033] where: [0034] the set {RM [0035] LF is the scale factor; it is the same for all coded transport channels; furthermore, it is determined when the composite channel is formed, so that the number of DTX symbols to be inserted is at a minimum when the composite channel bit rate is highest. [0036] It will now be described how the scale factor LF is determined in prior art. [0037] TFCS hereafter designates the set of transport format combinations. This set is finite because the number I of transport channels included in the composite channel is finite, moreover, each of them being only capable of having a finite number of transport formats. It should be noted that randomly choosing a transport format for each transport channel does not necessarily produce a combination of transport formats. Indeed, the combinations of transport formats in the TFCS set take into account in particular the available bit rate (N [0038] In addition, for any combination j of transport formats in the TFCS set, MBS(j) designates a set of coded block types for this combination of transport formats. A coded block type designates a piece of information defining: [0039] the transport channel that has produced the coded block under consideration, [0040] the transport format for which the coded block under consideration has been produced, and [0041] a sequence number representing the position of the coded block under consideration in the series of coded blocks produced by the transport channel for the corresponding transport format, when several coded blocks are produced for this transport format. [0042] It can then be understood that, a transport format combination defining a transport format for any transport channel, MBS(j) can be defined. In addition, k being a coded block type, I(k) designates the transport channel producing type k coded blocks and X [0043] Thus, in prior art, the scale factor LF is defined once for the set of transport channels of the composite channel by the formula (3) below so as to minimize the number of DTX symbols to be inserted ( [0044] This formula (3) is obtained as follows: if, for any transport format combination j, D(j) designates the size of the corresponding multiplexing frame and {circumflex over (D)}(j) an estimator of D(j), then {circumflex over (D)}(j) is given by the following formula (4):
[0045] Minimizing the number of DTX symbols to be inserted ( [0046] and equation (3) results from solving equation (5). It should be noted that D(j) and {circumflex over (D)}(j) respectively correspond to the bit rate of the composite channel and its estimator, when the composite channel bit rate is expressed as the number of symbols per radio frame. To solve (5), all that is required is to replace {circumflex over (D)}(j) by its expression (4), and in this expression to replace RF [0047] Formula (3) can then be written as:
[0048] However, this known solution has a major drawback. Indeed, it attempts to minimize the insertion of DTX symbols as the transmission power varies largely between transmitting a DTX symbol (zero power) and transmitting a real symbol (non-zero power). As a result the peak to average radio frequency power ratio increases as the proportion of inserted DTX symbols rises. And yet, the construction of a radio frequency amplifier is simpler when the peak to average radio frequency power ratio is low. [0049] In particular, it is an object of the invention to compensate for the above-mentioned major drawback. [0050] More particularly, the main object of this invention is to provide a rate matching method allowing to increase the minimization of the number of inserted DTX symbols, in comparison with the known solution, in particular for certain sets of transport format combinations. [0051] According to the invention, this main object, as well as others that will be apparent later on, are achieved by a rate matching method between at least two transport channels included within a composite channel, said method comprising at least one rate matching step for each transport channel, a rate matching ratio being applied to each transport channel, said rate matching ratio being equal to the product of a rate matching factor specific to said transport channel and a scale factor, said scale factor being common to the set of said transport channels of said composite channel, each of said transport channels being transmitted for at least one associated transmission time interval, each of said transmission time intervals having a duration specific to each of said transport channels, at least two of said transport channels having transmission time intervals of distinct duration, [0052] characterized in that it comprises successive steps of: [0053] defining, for said composite channel, a list of at least two transport channels ordered in descending order of the duration of their respective transmission time interval, said ordered list of transport channels being able to include at least one transport channel not transporting any data for at least one associated transmission time interval, [0054] determining, for said composite channel, at least two so-called global intervals for said ordered list of transport channels, said determined global intervals following each other in time, each of said determined global intervals corresponding: [0055] either to a transmission time interval associated with the first transport channel of said ordered list conveying data for said associated transmission time interval, [0056] or, in case none of the transport channels of said ordered list is transporting any data, to the smallest transmission time interval, [0057] assigning a scale factor to each determined global interval, said scale factor being constant for the duration of each determined global interval, at least two assigned scale factors having distinct values for at least two global intervals. [0058] According to the invention, in order to minimize the number of inserted DTX symbols, the scale factor LF may vary not only when the normalized estimator DN(j) of the composite channel bit rate is at a maximum for all transport format combinations, but also when the normalized estimator DN(j) is at a maximum for part of the transport format combinations. Thus, the number of inserted DTX symbols is minimized more often than with prior art. [0059] To this end, for minimizing the number of zero energy contribution symbols (DTX), the value of each of said assigned scale factors is determined according to the following formula:
[0060] N [0061] k being a coded block type; [0062] I(k) being a transport channel generating type k coded blocks; [0063] X [0064] F [0065] MSB(j) being the set of coded block types for the transport format combination j; and [0066] TFCSG(p) being the set of transport format combinations defining the same transport formats as a partial combination p of transport formats of the transport channels having transmission time intervals with duration lower than or equal to that of said determined global interval. [0067] According to another embodiment, the method further comprises the following successive steps of: [0068] defining a sub-list of at least one transport channel, said sub-list including the set of transport channels of the ordered list from the first transport channel to a given transport channel, said sub-list being ordered in descending order of the duration of the transmission time interval associated with each of said at least one transport channel of the sub-list, and [0069] substituting said sub-list to said ordered list, [0070] in order to reduce, for said composite channel, the number of scale factor values to be assigned to the set of said determined global intervals. [0071] This rate matching method is implemented advantageously within a telecommunication system using a CDMA type multiple access technology from a radio access network comprising at least one base station to at least one mobile station of said telecommunication system. [0072] If the method comprises a step of defining a sub-list of at least one transport channel, said at least one transport channel of the sub-list is selected by said radio access network of said telecommunication system. [0073] Another subject of the invention is a device for rate matching between at least two transport channels included within a composite channel, said device comprising at least rate matching means for each transport channel, a rate matching ratio being applied to each transport channel, said rate matching ratio being equal to the product of a rate matching factor specific to said transport channel and a scale factor, said scale factor being common to the set of said transport channels of said composite channel, each of said transport channels being transmitted for at least one associated transmission time interval, each of said transmission time intervals having a duration specific to each of said transport channels, at least two of said transport channels having transmission time intervals of distinct duration, characterized in that it comprises: [0074] means for defining, for said composite channel, a list of at least two transport channels ordered in descending order of the duration of their respective transmission time interval, said ordered list of transport channels being able to include at least one transport channel not transporting any data for at least one associated transmission time interval, [0075] means for determining, for said composite channel, at least two so-called global intervals for said ordered list of transport channels, said determined global intervals following each other in time, each of said determined global intervals corresponding: [0076] either to a transmission time interval associated with the first transport channel of said ordered list conveying data for said associated transmission time interval, [0077] or, in case none of the transport channels of said ordered list is transporting any data, to the smallest transmission time interval, [0078] means for assigning a scale factor to each determined global interval, said scale factor being constant for the duration of each determined global interval, at least two assigned scale factors having distinct values for at least two global intervals. [0079] Another subject of the invention is a base station of a telecommunication system comprising transmission means of at least two transport channels and a device as defined above. [0080] Another subject of the invention is a device for de-rate matching between at least two transport channels included within a composite channel, said device comprising at least de-rate matching means for each transport channel, a rate matching ratio being applied to each transport channel, said rate matching ratio being equal to the product of a rate matching factor specific to said transport channel and a scale factor, said scale factor being common to the set of said transport channels of said composite channel, each of said transport channels being transmitted for at least one associated transmission time interval, each of said transmission time intervals having a duration specific to each of said transport channels, at least two of said transport channels having transmission time intervals of distinct duration, [0081] characterized in that it comprises: [0082] means for defining, for said composite channel, a list of at least two transport channels ordered in descending order of the duration of their respective transmission time interval, said ordered list of transport channels being able to include at least one transport channel not transporting any data for at least one associated transmission time interval, [0083] means for determining, for said composite channel, at least two so-called global intervals for said ordered list of transport channels, said determined global intervals following each other in time, each of said determined global intervals corresponding: [0084] either to a transmission time interval associated with the first transport channel of said ordered list conveying data for said associated transmission time interval, [0085] or, in case none of the transport channels of said ordered list is transporting any data, to the smallest transmission time interval, [0086] means for assigning a scale factor to each determined global interval, said scale factor being constant for the duration of each determined global interval, at least two assigned scale factors having distinct values for at least two global intervals. [0087] Finally, another subject of the invention is a mobile station of a telecommunication system comprising means for receiving at least two transport channels and a de-rate matching device such as defined above. [0088] Other features and advantages of the invention will be apparent from reading the following description of two preferred embodiments of the invention, by way of example only and not to be restrictive, with reference to the accompanying drawings, wherein: [0089]FIG. 1, already described in the preamble, is a simplified flow chart of a known data processing technique for transmitting a composite channel over the downlink; [0090]FIG. 2, already described in the preamble, shows four timing charts of a first traffic example of four transport channels represented by their transport block sets, the transport channels being included in the same composite channel; [0091]FIG. 3 is a simplified flow chart of a first embodiment of the rate matching method according to the invention; [0092]FIG. 4 shows the global intervals of the transport channels of FIG. 2 for different embodiments of the invention; [0093]FIG. 5 is a simplified flow chart of a second embodiment of the rate matching method according to the invention; [0094]FIG. 6 illustrates a timing chart of a composite channel made of the four transport channels of FIG. 2, rate matched using the known technique; [0095]FIG. 7 illustrates a timing chart of a composite channel made of the four transport channels of FIG. 2 obtained when the first embodiment of the rate matching method according to the invention has been implemented; [0096]FIG. 8 illustrates a timing chart of a first composite channel made of the four transport channels of FIG. 2 obtained when the second embodiment of the rate matching method according to the invention has been implemented; [0097]FIG. 9 illustrates a timing chart of a second composite channel made of the four transport channels of FIG. 2 obtained when the second embodiment of the rate matching method according to the invention has been implemented. [0098] According to a first embodiment, a list is established comprising the set of transport channels of the composite channel by sequencing them in descending order of their respective TTI interval duration. This ordered list may be truncated, i.e. that only the n first transport channels of the list are maintained together with their sequence in a sub-list, for a given non-zero number n of transport channels. Establishing a sub-list is treated by a second embodiment to be described later on. The steps of the first embodiment are illustrated in FIG. 3. In a step referenced as [0099] The global intervals are defined as follows: [0100] a) The transmission start time for a given channel is considered. For all transport channels, this time is also the start time of its first associated TTI interval. [0101] b) For the time under consideration, the list is then scanned from the first transport channel on until a transport channel is found that transmits a non-zero data amount during its TTI interval starting at the time under consideration. If such a transport channel is found, then the new global interval coincides with the TTI interval of the transport channel of the list starting at the time under consideration. If such a transport channel is not found in the list, i.e., if simultaneously no transport channel of the list is transmitting data, then the global interval coincides with the TTI interval of the last transport channel of the list starting at the time under consideration. [0102] c) A global interval having thus been determined, the end time of this global interval is considered, and step b) is repeated iteratively, for this new time under consideration, in order to determine the next global interval. Thus, one by one, the set of global intervals, and consequently of corresponding scale factors, is determined for the composite channel under consideration. [0103] This step [0104] For this example, the successive global intervals are determined by following the line referenced as [0105] In step [0106] In order to determine the value of the scale factor, for each global interval, a transport channel set MG grouping the transport channels of the ordered list is defined, the TTI interval duration of which is at least the same as of the global interval under consideration. It should be noted that the transport channel set MG may vary depending on the global interval under consideration. A partial combination of transport formats can then be defined as the information defining the respective transport formats of each transport channel in the set MG. Assuming that the transport format ID numbers are as in FIG. 2, then the partial transport format combinations associated with global intervals are as follows, the ordered list being (A,B,C,D):
[0107] For each partial transport format combination p, a part marked TFCSG(p) of the TFCS set comprising all transport format combinations including the partial combination p can be defined. [0108] Referring again to FIGS. [0109] It should be noted that the transport format combination ((A,0),(B,0),(C,0),(D,3)) is never used in the example of FIGS. 2 and 4. Thus, considering the TFCS set of transport format combinations indicated as (7), the different TFCSG parts determined by the partial transport format combinations corresponding to each global interval are given below: [0110] For the global interval referenced as [0111] For the global interval referenced as TFCSG(((A,0),(B,0),(C,2)))=(((A,0),(B,0),(C,2),(D,1)), ((A,0),(B,0),(C,2),(D,2))} [0112] For the global interval referenced as TFCSG(((A,0),(B,0),(C,0),(D,2)))={((A,0),(B,0),(C,0),(D,2))} [0113] For the global interval referenced as TFCSG(((A,0),(B,0),(C,0),(D,0)))={((A,0),(B,0),(C,0),(D,0))} [0114] For the global interval referenced as [0115] The scale factor LFG [0116] The rate matching ratios RF [0117] In a second embodiment illustrated by FIG. 5, it is envisaged to establish a sub-list during a step referenced as [0118] E.g., in the list (A,B,C,D), the sub-lists (A,B,C) or (A) can be defined. When a sub-list is defined, the ordered list is substituted to the defined sub-list and the series of global intervals is determined through steps a), b), and c) described above. It is then found that for the sub-list (A,B,C), the global intervals [0119] The partial transport format combinations are then:
[0120] The TFCSG parts determined by the partial transport format combinations for the global intervals [0121] For the global interval referenced as [0122] Thus, for the TTI interval of transport channel D corresponding to the frame numbered [0123] In the case of sub-list (A), for the global interval referenced as [0124] The performance of the rate matching method according to the invention in terms of minimizing DTX bits is illustrated by FIGS. [0125] For the sake of simplicity, FCS sequences are zero length (no error detection), channel encoding is transparent (no channel encoding), and the rate matching factors RM [0126]FIG. 6 shows a timing chart of a composite channel composed of the four transport channels A, B, C, D of FIG. 2 rate matched using the known prior art technique. FIGS. [0127] The cross-hatched regions, referenced respectively as [0128] In FIG. 6, the maximum bit rate of the composite channel is reached for the frame numbered [0129] is at a maximum in the TFCS set given by item ( [0130] In FIG. 7, rate matching is performed according to the invention using the complete ordered list (A,B,C,D). Rate matching is then based on the global intervals [0131] In FIG. 8, rate matching is performed according to the invention using the sub-list (A,B,C). Rate matching is then based on the global intervals [0132] In FIG. 9, rate matching is performed according to the invention using sub-list (A). Rate matching is then based on the global intervals [0133] For the sake of simplicity, the scale factor computation will only be detailed for FIG. 9. Indeed, there are only two global intervals and therefore only two scale factors to be calculated. In-the first global interval [0134] these formulas being defined for all transport channels i of the set {A, B, C, D} of composite channel transport channels. [0135] For the second global interval [0136] In this FIG. 9, the composite channel reaches its maximum bit rate not only at the frame numbered [0137] is at a maximum for the set referenced as TFCSG(((A,0))). Thus, for the frames numbered [0138] It should be noted that the invention can be applied, without limitation, to a rate matching method wherein the rate matching factor RM [0139] RF [0140] RM [0141] RM [0142] Such a dependence may have certain advantages. Indeed, e.g. when a turbo code is used to perform the step referenced as Referenced by
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