Method and apparatus for controlling transmission of packets in a wireless communication system

Method and apparatus for controlling the transmission of packets in a wireless communications system.

Field of the Invention

The present invention relates to wireless communications, such as those provided by systems as specified in version 5 of the Broadband Code Multiple Division Access (WCDMA) of the 3GPP (Third Generation Association Project), Packet Access High Speed ​​Downlink (HSDPA), but also those provided by other types of wireless communications systems that provide for packet transmission. More particularly, the present invention relates to the search for mobile stations that communicate with a base station in said communication systems.

Background of the invention

FIG. 1 illustrates a radio frame that includes a series of complex segments (in phase and quadrature) divided into fifteen intervals. The radio frame may have a duration of ten milliseconds (10 ms) and include 38,400 segments. In the Third Generation Association Project (3GPP), each of these frames is called the Transmission Time Interval (TTI) that defines the periodicity with which Transport Block Sets are transferred to the physical layer over the interface Radiocommunications Thus, each interval includes 2,560 segments, which can represent, for example, ten symbols of 256 segments (with an SF of 256). A frame / interval / segment structure of this type is one of the characteristics of the broadband CDMA communications system, 3GPP, which is currently being considered. The radiocommunication signal transmitted by a BS in such a communications system is the sum of data and control bits modulated by widening and randomization and a synchronization channel without randomization. The data and control bits are typically modulated by widening by replacement, either at the bit level (in DS-CDMA systems) or at the block level, by an orthogonal sequence or sequences, such as the Walsh-Hadamard sequences . (Occasionally, this option is called orthogonal modulation m-aria). As indicated above, then the results modulated by broadening are usually randomized by a bit-level module 2 addition of a pseudo-noise (PN) randomization sequence.

It will be appreciated that the data bits include user information, such as audio, video and text information, and that the information of different users is made to be differentiable, according to the operating principles of the CDMA, through the use of modulation sequences by differentiable widening, such as mutually orthogonal Walsh-Hadamard sequences. In this case, in a way the Walsh-Hadamard sequence (s) of each user defines the communication channel of that user, and therefore it is said that this differentiable sequences channel the user's information. Sequence construction according to its correlation properties is described in US Patent No. 5,353,352 issued to P. Dent et al by Multiple Access Coding for Radio Communications and in US Patent No. 5,550,809 issued to G. Bottomley et al by Multiple Access Coding Using Bent Sequences for Mobile Radio Communications.

It is desirable to provide various types of communication services that meet various consumer demands, such as voice telephony, facsimile, email, video, Internet access, and so on. On the other hand, it is expected that users may wish to access different types of services at the same time. For example, a videoconference between two users would involve both voice and video support. Some services require higher data rates than others, and certain services would benefit from a data rate that may vary during communication.

FIG. 2 represents a typical tree structure for sequences, or codes, of Walsh-Hadamard. The levels in the code tree define channeling codes of different lengths, which correspond to different spreading modulation factors. In FIG. 2, the root of the tree is indicated by the C1,1 code that has a spreading modulation factor SF = 1, the level 1 of the tree includes the C2,1 and C2,2 codes that each have some factors of broadening modulation of 2, and so on. In each of the levels, corresponding illustrative sequences or codes are indicated. For the root level, the example shown is [1], for level 1, the sample codes shown are [1 1] and [1 -1], and so on. In the notation Ck, i illustrated, k is the spreading modulation factor SF and the index i simply differentiates the codes at the same level. It will be appreciated that the tree continues to branch as it moves to the right in FIG. two and that it is not necessary that the code sequence at the root level have only one element as illustrated.

Not all codes in a code tree can be used simultaneously in the same cell or other environment susceptible to mutual interference since not all codes are mutually orthogonal; A code can be used if and only if no other code is used in the path from the specific code to the root of the tree or in the subtree that is below the specific code. This means that the number of available channeling codes is not fixed but depends on the speed and the spread modulation factor of each one.

of channels in the group of channels that may potentially present mutual interference.

The channelization codes that can be chosen can be randomly assigned from the codes that can be chosen available in the structure of the code tree for different speed channels and modulation factors by spreading, which means that the codes that can be selected Choose can be assigned without any coordination between the different connections, while maintaining orthogonality. In the uplink, different users (connections) use different spreading modulation codes, so that all the spreading modulation codes of a tree can be used for each of the users without coordination between the different users. The downlink situation could be different since the BS typically uses only a randomization code for all users (connections). In this way, widening modulation codes cannot be assigned as freely; Coordination between users is necessary.

In WCDMA-based systems, high-speed data transmission can be enabled, for example, by means of the technique called high-speed downlink packet access (HSDPA). High speed downlink packet access (HSDPA) may include functions such as automatic hybrid repeat request (HARQ), adaptive coding and modulation (AMC) and / or rapid cell selection (FCS). These functions are known to those skilled in the art and therefore will not be explained in more detail. A more detailed description of these and other functions of the HSDPA can be found, for example, in a technical report of the third generation partnership project No. 3G TR25.848 version 2000 entitled "Physical Layer Aspects of UTRA High Speed ​​Downlink Packet Access" . It will be appreciated that although the HSDPA has been specified for use in the WCDMA, similar basic principles can be applied to other access techniques.

At present it is considered that in the access by high-speed downlink packets (HSDPA) each user equipment that receives data on a shared high-speed downlink channel (HS-DSCH) also has a dedicated channel (DCH) ) associated and assigned. A dedicated channel map can be established with a dedicated physical channel (DPCH) in the physical layer. Typically, the DPCH is divided into a dedicated physical data channel (DPDCH) and a dedicated physical control channel (DPCCH) in both the uplink and the downlink. Data such as power control orders, transport format information, and dedicated pilot symbols are transmitted in the DPCCH. On the DPCCH, in the uplink, information such as diversity feedback information can also be transmitted. The HS-DSCH can be mapped with one or more high-speed physical downlink shared channels (HS-PDSCH) in the physical layer.

Typically, the associated dedicated channel is provided on both the downlink and uplink. Typically, the dedicated channel is used to carry information / signaling associated with the HSDPA as well as other dedicated data such as voice and control data. The user equipment can communicate with several base stations at the same time. For example, the associated dedicated channel can be found in a uniform handover.

In addition to the associated dedicated channels, the HS-DSCH can also be associated with a shared control channel (SCCH). The SCCH can be used to transport specific information / signaling from the HS-DSCH to those users who receive data about the HS-DSCH.

One of the current proposals is to use the dedicated channel to inform the user team that it has data to read on the HS-DSCH and the SCCH. That is, only those users who receive data at a given time will receive an indication about the dedicated channel. The dedicated channel can be called the pointer channel as it points to the shared channels. The dedicated channel may also contain information on modulation and coding schemes, power levels and similar parameters used for shared channels. This information can also be sent on the shared channel. On the other hand, the shared control channel is used to carry information that is specific to the data transmitted over the shared data channel (HS-DSCH). This information may contain, for example, packet numbers for the HARQ and similar aspects. The shared control channel can be sent over a separate code channel (code multiplexed) or using the same code channels as the HS-PDSCH (time multiplexed).

Unlike the dedicated channel, it is considered that the HS-DSCH is not in uniform handover. That is, each base station is considered to have its own shared channel and it is considered that the user equipment receives data only from one base station at a time. The so-called rapid cell selection (FCS) technique can be used to switch data transmission from one base station to another. However, shared channels do not use power control. It is proposed, however, that shared channels be transmitted with a fixed or semi-fixed power. The expression "semi-fixed" means in this case that the power is not changed frequently. The power could be, for example, a specific parameter of each cell.

In the currently proposed arrangements, the high-speed downlink shared channel (HS-DSCH) is planned to be associated with a dedicated channel which would transport on the downlink

less information regarding the timing at which the receiving station will receive over a shared channel. Possibly, the associated dedicated channel can also carry other information. In the uplink, the associated dedicated channel can carry, for example, the acknowledgments (ACK) required for a quick HARQ.

The Transmission Time Interval (TTI) for the HSDPA will be shorter than for the WCDMA Version 99. TTI lengths of 1, 3, 5 and 15 intervals, corresponding respectively, to 0.67 ms, 2 ms, have been proposed. 3.33 ms and 10 ms. Currently, a TTI of 3 intervals, that is, 2 ms, is the most likely option and is considered as the preferred solution in this text.

Problem contemplated by the invention

In a packet access system, such as HSDPA, a user typically accesses the communications link (channel) and the media only when the user has data to be transmitted or received. To effectively use the communications link, several users normally share the same link.

So that each user knows when there is data to receive and therefore knows when to access the communications link, in some systems a link master module notifies the user that there is a data packet about to be transmitted. Therefore, in systems of this type, each of the users must listen more or less continuously to a package search channel.

As a communications link can be statistically multiplexed among a large number of users, there will also be a multitude of search channels per required packages, one for each of the users. To make the number of search channels as large as possible (ie, to maximize the number of codes and code channels available), in some systems a widening modulation factor is used for the search channel, and it is done that the widening modulation factor be as high as possible with a view to allowing the greatest possible number of users to use the same part of a code tree.

A high spread modulation factor for a search channel implies a very low bit rate in the channel. On the other hand, a highly flexible and adaptive system, such as the proposed HSDPA, may require the transmission of a multitude of parameters to a mobile station along with each of the packets.

For this reason, the prior art has proposed that another set of code channels, other than the search channel, be used for signaling the parameters. (When another set of code channels is used for the signaling of the parameters, the search channel can also be referred to as either a search indicator channel or a pointer channel, since it or indicates that there is data to be received on the parameter signaling channel, or points to a certain parameter signaling channel). The number of such code channels should be the same as the number of users multiplexed by code for any specific transmission interval. Since this number is usually much smaller than the number of active users, the prior art has proposed that the parameter signaling channels be shared among the active users. See, for example, chapter 6.3.2.1.2 (two-stage signaling approach) of 3GPP TR 25.855 v1.1.0.

As mentioned earlier, in the HSDPA, a fixed spread modulation factor is used for the data code channels and at this time it has a value of 16. Therefore, at most there are sixteen data code channels. Full speed available. At least one of the channels, that is, one of the branches of the code tree, must be assigned for the common pilot channel (CPICH) used, for example, for the estimation of the channels in the mobile station and other common channels as well as for dedicated channels (packet search) and parameter signaling channels (also called shared control channels). The remaining fifteen code branches, according to the prior art, are temporarily assigned either to a user, or they are assigned at most to fifteen independent users. In the first case, a parameter signaling channel is necessary; and in the second case, fifteen parameter signaling channels are necessary. Typically, it is considered that the shared data channel is shared within a given TTI by a number of users, which are multiplexed by code. In Fig. 3, an example with four shared control channels is shown. In either case, there may be more than fifteen active users who share the data channels (through multiple time division access).

According to the prior art, each active mobile station decodes its own search channel. When there is a transmission for a specific mobile station, the search channel corresponding to the mobile station indicates it. Additionally, the search channel corresponding to the mobile station indicates the code channel (parameter signaling) in which the parameters for the transmission interval are signaled. Next, the mobile station decodes the assigned parameter signaling channel, which enables the mobile station to then decode the specific data transmission.

The main problem of the previous protocol is that if the content of the search channel, the content of the parameter signaling channel, and the content of the data channel (s) are sent sequentially, in that case

three frames or transmission time intervals (TTI intervals) are necessary to complete a data transmission. For this reason, the prior art further provides that the entire content of the three different channels in full be sent simultaneously, that is, in a single TTI.

If all the content of all three different channels is sent simultaneously, the mobile station must temporarily store all the channels that must be decoded, that is, all the channels of parameter signaling code and all the data channels; In the worst case scenario for HSDPA, this amounts to a total of thirty independent channels. The provision, in the mobile station, of a buffer large enough to manage thirty channels would be complicated and expensive. As an alternative to the provision of the buffer memory in the mobile station, the prior art also provides for the channels to be demolished in widening and then stored temporarily, instead of temporarily storing them at the level of the segments (i.e., before demodulate them in widening, so that the channels are temporarily stored with the widening modulation code, which requires more memory). An alternative of this type requires less memory, although it needs a larger number of spreading modulators.

A way of sending the content of the three types of channels to a mobile station (the search channel, the parameter signaling channel, and the data channel) is required without requiring as many spreading demodulators as in the prior art. three channels at a time, and without requiring three TTIs as in the prior art of one channel at a time.

Summary of the invention

Accordingly, the present invention provides a packet issuing entity, such as a base station, and a packet receiving entity, such as a mobile station, also provides methods by which the packet issuing entity and the packet receiving entity operate. so that the packet issuing entity communicates a packet to the packet receiving entity, and a corresponding system that includes both the packet issuing entity and the packet receiving entity, so that the methods intended to be used in a context in which the packet issuing entity and the packet receiving entity communicate via a packet communication system uses a plurality of parameter signaling channels (SCCH), and they also use a plurality of shared data channels (SDCH) and operate according to a protocol in which when packet data is to be transmitted from the packet sending entity to the packet receiving entity, communication between the packet issuing entity and the packet receiving entity is produced through one or more transmission time intervals (TTI intervals). The methods are such that once a parameter signaling channel is assigned to the packet receiving entity to communicate a packet, the assigned parameter signaling channel is used by the packet receiving entity in each subsequent TTI provided that it exists by at least a part of the package in the subsequent TTI, and when there is at least a part of the package in the subsequent TTI, for the subsequent TTI the packet receiving entity demodulates in broadening and decodes only one parameter signaling channel together with the data channels, and when there is not at least a part of the package in the subsequent TTI, for the subsequent TTI the entity packet receiver demodulates in widening all the parameter signaling channels, and decodes either all, or one, or none of the parameter signaling channels.

In a first aspect of the invention, a method for the operation of the packet issuing entity is provided, including said method: a parameter transmission stage, which achieves that the packet emitting entity transmits at least some of the parameters to the packet receiving entity to decode some or all of the shared data channels using at least one of the channels of parameter signaling, a stage of data provision, which achieves that the packet issuing entity provides the packet receiving entity with the data to be communicated using at least one of the shared data channels according to the parameters provided on the at least one parameter signaling channel; and an additional parameter transmission stage, which ensures that the packet issuing entity continues to use at least one parameter signaling channel to transmit parameters with a view to decoding any additional data transmitted on at least one of the channels of data shared for the same packet receiving entity in subsequent consecutive TTIs.

In a further aspect of the first aspect of the invention, in the parameter transmission stage, the packet emitting entity transmits to the packet receiving entity, within a TTI, at least some of the parameters to decode some or all of the shared data channels within the following TTI. Still in a further aspect, at the data provision stage, the packet issuing entity provides the packet receiving entity, in the TTI that comes immediately after the TTI in which the parameter signaling channel is transmitted, the data to be communicated using at least one of the shared data channels according to the parameters provided in the at least one parameter signaling channel.

In a second aspect of the invention, a method is provided for the operation of the packet receiving entity, said method including the steps in which: until the packet issuing entity assigns a channel

of signaling parameters to the packet receiving entity, the packet receiving entity is demolished in widening all the parameter signaling channels and to decode a predetermined subset of the parameter signaling channels, in which the predetermined subset of the parameter signaling channels is either all, either one, or none of the parameter signaling channels, once a parameter signaling channel is assigned to the packet receiving entity for the first time, the packet receiving entity is made to interpret the assignment as an assignment of a parameter signaling channel for the current TTI, and the packet receiving entity is demolished in broadening and decoding the parameter signaling channel assigned in the current TTI with a view to obtaining parameter data from the parameter signaling channel; the packet receiving entity is made to use the parameter data in reading the content of the shared data channels in the subsequent TTI; The packet receiving entity is made to monitor information communicated by the packet issuing entity to determine whether the following TTI includes at least a part of the package; in each of the TTIs up to the TTI prior to the last TTI in which a part of the packet is transmitted through the data channels, the packet receiving entity is demolished in widening only the assigned parameter signaling channel and that also decode the assigned parameter signaling channel; and for the last TTI in which a part of the packet is transmitted through the shared data channels, the packet receiving entity is demolished in widening only the assigned parameter signaling channel and also temporarily storing the channel of assigned signaling of parameters.

Thus, the invention provides a method and an arrangement for searching a mobile station, method and arrangement that minimize the complexity of the mobile and maximize the processing time of the base station if a hybrid automatic repeat (HARQ) request is used.

Brief description of the drawings

These and other objectives, features and advantages of the invention will become apparent when considering the following detailed description, referring to the attached drawings, in which:

Fig. 1 is a scheme illustrating a radio frame comprising CDMA segments divided between fifteen intervals, according to the prior art;

Fig. 2 is a diagram illustrating a code tree defining channelization codes of length k, according to the prior art; and

Fig. 3 is a scheme illustrating the search for a mobile station (alternatively known as user equipment, or mobile station), according to one of the embodiments of the invention;

Fig. 4 is a scheme illustrating the search for a mobile station, according to another embodiment of the invention;

Fig. 5 is a scheme illustrating the search for a mobile station, still according to another of the embodiments of the invention; and

Fig. 6 is a scheme illustrating the search for a mobile station, still according to another of the embodiments of the invention.

Best way to carry out the invention

The invention will now be described in an application to a communications system that implements the hybrid automatic repeat (H-ARQ) request with high speed downlink packet access (HSDPA), as set forth in version 5 of the Multiple Access by Division of Broadband Code (WCDMA) of the 3GPP (Third Generation Association Project), HSDPA. However, it should be understood that the invention is usable in wireless communication systems with or without the HARQ. The invention offers the advantage of not requiring three transmission time intervals (TTI intervals), which is especially beneficial in the case of systems using HARQ.

Invention

The invention provides a protocol that amounts to a compromise between the two approaches described above in the prior art, namely, the approach of three channels at a time and the approach of one channel at a time. With the invention, the transmission of the start of a data packet to a specific mobile station is staggered (divided) into two successive transmission intervals, instead of one or three, as in the prior art.

According to the invention, while waiting for the transmission of a packet, a mobile station temporarily stores all the parameter signaling channels and decodes the search channel assigned to the mobile station. In this phase, the mobile station must temporarily store up to fifteen channels, although most likely

Store a lot less. As in the prior art, when the search channel assigned to the mobile station indicates that a packet is to be transmitted, it also indicates which parameter signaling channel will be used.

According to the invention and unlike the prior art, once a parameter signaling channel has been transported to a mobile station for the first time, that same parameter signaling channel (which means the same channelization code) is used in all other consecutive transmission time intervals in which data is sent to the mobile station (ie, data belonging to the same packet transmission burst). Therefore, at this stage, according to the invention, the mobile station may have to temporarily store fifteen data channels, but it does not need to temporarily store additional parameter signaling channels, since the same parameter signaling channel is used throughout a continuous data transmission corresponding to a user, such as, for example, in Fig. 4, the data being provided in the SDCH in columns 2 to 4.

With the present invention, the broadening demodulation of the code (the number of rake branches) is optimized: when there is no data being transmitted to a mobile station, all the “data” branches are free and can be used to demodulate in shared control channels. When the data channel (or part thereof) is assigned to a mobile station, the mobile station is informed of this fact during the previous TTI on one of the shared control channels. If more data is to be sent to the same mobile station in the following TTIs, in that case the parameters will be sent using the same shared control channel as for the first transmission. Thus, when data is received on a shared data channel, the mobile station only needs to demodulate in widening (and decode) a shared control channel.

Referring now to Fig. 3, which illustrates the invention for use with a communications system that implements the HSDPA, the dedicated physical channel DPCH is used as the search channel. In the illustration in Fig. 3, there are four SCCH shared control code channels used as parameter signaling channels, and ten SDCH shared data code channels used as shared data channels. The limits of the TTI 15 are indicated by vertical lines of data that extend from the row corresponding to the DPCH through all the rows corresponding to the SDCH. The DPCH for the different TTIs, called DPCH intervals in this case, are shown in such a way that they have numbers that have one of the following values: 0, 1, 2, 3 or 4, which act as channel indicators (indicating a SCCH specific). The non-zero numbers shown are a subset of the set of numbers 1 to 4 of the SCCH shared code channel, which indicate the SCCH number to be used by the mobile station for the current TTI. A value of 0 in a DPCH interval indicates that no data is available for the mobile station in the next TTI and therefore no parameter information is available on any of the control channels shared in the current TTI. A block with a stroke outline means that the mobile station demodulates in widening and temporarily stores the received code channel (shared control channel) although it is not necessary to decode it (read). A block with a continuous contour means that the mobile station demodulates in widening and decodes (reads) the code channel. (All blocks shown in gray with a continuous border are blocks that must be demodulated in widening and decoded by the mobile station. Blocks with oblique lines are blocks not intended for the mobile station, that is, a gray block with a continuous edge and oblique lines is a block not intended for the mobile station although it must be demodulated in widening and decoded by the mobile station , while a white block with a border of dashes and oblique lines is a block not intended for the mobile station, however, it must be demodulated in widening and temporarily stored by the mobile station. For other mobile stations, TTI intervals without frames may be used).

(Note that it is possible to change the order of modulation by widening and randomization and the demodulation in corresponding widening and randomization. However, in the transmitter the coding must be carried out before the widening and randomization modulation, and in the receiver, the decoding must be done last).

Thus, as indicated in Fig. 3 according to the invention, in those TTIs during which the mobile station does not receive data on an SDCH shared data channel, the mobile station demodulates on widening and temporarily stores all (or a predefined set of) SCCH shared code channels.

When the SCCH shared control channel is assigned to the mobile station (to receive data in the next TTI with the correct parameters), the network, according to the invention, will only use the same SCCH in all of the following consecutive TTIs during the which data will be subsequently transported (the continuation of a packet burst), so that the mobile station only needs to demodulate in widening and decode an SCCH when they are demodulated in widening and data is decoded on the SDCH (the). When the data transmission has been completed (for a packet burst), the mobile station demodulates all SCCHs once again until a SCCH is reassigned (which may be different from the SCCH assigned previously) ; the mobile station uses the newly assigned SCCH not only for the current TTI, but for all subsequent consecutive TTIs during which

They transmit data. As illustrated in Fig. 3, according to the invention, the data channels are demodulated in widening only when there is data to be received, and all control channels are received only when there is no simultaneous data.

Figs. 4 to 6 show two other arrangements corresponding to the DPCH and the SCCHs according to the invention. Referring next to Fig. 4, the DPCH is considered to carry an individual indicator bit, that is, either a 0 or a 1. (Those skilled in the art will understand that in order to transport a bit of information, in practice it may be necessary to transmit several physical bits by air, that is, the bit can be repeated or alternatively protected using known channel coding techniques) . The indicator bit indicates whether the mobile station is going to receive data in the next TTI and therefore if the mobile station must read (decode) the shared control channels to obtain the parameter information. The mobile station must decode all (or a predefined subset of) the SCCHs to find out on which SCCH the corresponding parameter information is transmitted . To transport to the mobile station which SCCH to use, on that SCCH the mobile station will use, one or the other identifier of the mobile station can be sent; alternatively, the CRC (cyclic redundancy check) can be specific to each mobile station (that is, so that the other mobile stations obtain a decoding fault when they attempt to decode the SCCH). In subsequent TTIs, the same SCCH is used as in the previous case, that is, it should be demodulated in widening and decode only one SCCH simultaneously with the received data channels. When the DPCH with a 0 for the indicator bit indicates that no data is available for the mobile station in the next TTI, in that case the SCCH (T) of the current TTI is not decoded (s) but rather the (the) it (s) must be demodulated in widening and temporarily stored, as indicated in Fig. 4. For the first TTI in which the binary indicator changes from one to zero, only the assigned SCCH is demodulated, and then it is stored temporarily, not decoded (knowing the mobile station, from the binary indicator, that the SCCH does not contain parameter information for it in the current TTI).

Referring now to Fig. 5, in another of the arrangements according to the invention, the DPCH does not carry any indicator bit (such as in Fig. 4) or a channel indicator (such as in Fig. 3); In some implementations, not even a DPCH is used. Therefore, when the mobile station is not receiving data, it must demodulate in widening and decode all (or a predefined set of) SCCH channels to find out if one of them is destined for it. Again, the SCCH must either expressly transport a mobile station identifier or indicate the mobile station indirectly, for example using a specific CRC of each mobile station, as explained above in relation to Fig. 4. Once the mobile station finds control information for it on one of the SCCHs, reads the parameters and receives data in the following TTIs according to the parameters. In subsequent consecutive TTIs, control information on the same SCCH is sent, and the mobile station only needs to read an SCCH simultaneously with the data reception.

Referring now to Fig. 6, still in another of the arrangements according to the invention, the DPCH is again used to transport an individual indicator bit (either a 0 or a 1), as in the arrangement illustrated in Fig. 4, although in the arrangement shown in Fig. 6, the indicator bit is transmitted in the TTI that precedes the TTI in which the binary indicator in Fig. 4 is transmitted. Since the indicator bit cannot indicate which SCCH to decode, if there is no simultaneous data (that is, if the TTI does not also carry at least part of a packet), all SCCHs must be decoded. As in the arrangement illustrated in Fig. 4, in the subsequent consecutive TTIs (until the entire burst has been transported) the same SCCH is used, and whenever there is simultaneous data in the subsequent TTIs, only a single SCCH must be demodulated in broadening and decoding. As in Fig. 4, there are at least two ways according to which the parameter signaling channel that is being assigned can be communicated to the mobile station, that is, either expressly (using, for example, an identifier of the mobile telephone over the signaling channel of parameters that are being assigned, or indirectly, using an error detection code, such as a CRC code, to encode the SCCH that is being assigned ie a code used exclusively by the mobile). As in the arrangement illustrated in Fig. 4, the indication on which channel is being assigned is not provided until the TTI immediately preceding the TTI on which at least part of the package is transported for the first time.

In one of the alternative embodiments, the widening modulation (and the widening demodulation) could be performed "in an interlaced way", that is, the same widening demodulator would demodulate a widening segment of a channel 1, then a segment of channel 2, and so on, and then the broadening demodulation would start from scratch with the next segment of channel one, and so on.

Scope of the invention

It should be understood that the provisions described above are only illustrative of the application of the principles of the present invention. In particular, although the invention has been shown and described in the context of a base station communicating a packet to a mobile station, there is nothing about the invention that limits its use to communication between a base station and a mobile station. The invention is useful in any situation where a packet issuing entity communicates a packet to a packet receiving entity in which the packet issuing entity is typically simultaneously in communication with several receiving entities.

packets, provided that the packet communicates using a packet communication system that includes a

plurality of parameter signaling channels that act as shared control channels (the channels

designated as SCCH in the description above), and also using a plurality of data channels

5 shared (the channels designated as SDCH in the description above), operating the system

packet communication according to a protocol in which when packet data will be transmitted from the

packet issuing entity to the packet receiving entity, the communication between the issuing entity of

packets and the packet receiving entity occurs over one or more transmission time intervals. The

Those skilled in the art will be able to conceive numerous modifications and alternative arrangements without departing from the scope of the present invention, and the appended claims are designed to understand said

Modifications and provisions.