WO2013068195A1

WO2013068195A1 - Code-distributed physical channel definition

Info

Publication number: WO2013068195A1
Application number: PCT/EP2012/070141
Authority: WO
Inventors: Przemyslaw Czerepinski; Michal PANEK
Original assignee: Nokia Siemens Networks Oy
Priority date: 2011-11-08
Filing date: 2012-10-11
Publication date: 2013-05-16

Abstract

There are provided measures for code-distributed physical channel definition. Such measures may exemplarily comprise distributing at least one physical channel over at least two code channels, and transmitting the at least two code channels with the at least one distributed physical channel. The physical channel distribution may exemplarily comprises an allocation of data elements of the at least one physical channel to (unused) symbols of the at least two code channels.

Description

Code-distributed physical channel definition

Field The present invention relates to a code-distributed physical channel definition. More specifically, the present invention exemplarily relates to measures (including methods, apparatuses and computer program products) for a code-distributed physical channel definition. Background

The present document basically relates to a physical channel definition for/in wireless communications, in particular code-multiplexed wireless communications.

In wireless communications, a physical channel to be communicated is allocated to a communication channel. In CDMA/WCDMA communications, a communication channel is a code channel defined by a predetermined code, e.g. an OVSF code channel, which typically exhibits a slot format, with each slot comprising a predetermined number of symbols. The symbols of such code channel, which represent the resources or resource elements, are modulation symbols, e.g. QPSK symbols when QPSK modulation is employed. When a specific piece of data is to be communicated on/by a physical channel, the data elements (e.g. bits) thereof are to be allocated to respective symbols of the communication channel to be used for wireless communications. In the case of CDMA/WCDMA communications using a code channel, a number of data elements of the physical channel (i.e. a piece of data thereof), are typically allocated to a respective number of symbols of the code channel, wherein the thus allocated symbols are located at equivalent slot positions in a respective number of consecutive slots in the slot format of the code channel. For example, two bits of a piece of data are allocated to two symbols at a specific slot position in two consecutive slots of the code channel Typically, a specific piece of data to be communicated on/by a physical channel has a certain update period. For example, the piece of data is to be updated, i.e. the communication thereof is to be repeated, every/after three slots of the code channel when the update period equals three slots.

In view of the above-outlined conventional physical channel definition, problems in terms of resource utilization may occur. For example, when a piece of data with two bits and an update period of three slots is to be communicated on/by a physical channel, the typical slot format of a code channel results in that only the first and second slots could be utilized for physical channel communication (wherein in each of these slots a specific slot position is occupied by one of the two data elements, respectively), while the third slot in the update period remains unused.

Namely, especially when a piece of data exhibits an update period of a slot number larger than a number of data elements of the piece of data, less pieces of data than theoretically possible could be communicated on a code channel, i.e. less physical channels than theoretically possible could be mapped/allocated to a code channel. Alternatively, due to certain resource utilization, an additional code channel could be required to be used/ established for enabling communication of a desired number of data elements, i.e. mapping/allocation of a desired number of physical channels.

Accordingly, by using the conventional physical channel definition, a poor resource utilization efficiency results under certain conditions.

In view thereof, there is a need to provide for an improvement in physical channel definition in the context of, thus facilitating, an improved resource utilization efficiency results, at least under certain conditions.

Summary Various exemplary embodiments of the present invention aim at addressing at least part of the above issues and/or problems and drawbacks.

Various aspects of exemplary embodiments of the present invention are set out in the appended claims.

According to an exemplary aspect of the present invention, there is provided a method comprising distributing at least one physical channel over at least two code channels, and transmitting the at least two code channels with the at least one distributed physical channel.

According to an exemplary aspect of the present invention, there is provided a method comprising receiving at least two code channels with at least one distributed physical channel being distributing over the at least two code channels, and assembling the at least one physical channel from the received at least two code channels.

According to an exemplary aspect of the present invention, there is provided an apparatus comprising an interface configured to communicate with at least another apparatus, and a processor configured to cause the apparatus to perform : distributing at least one physical channel over at least two code channels, and transmitting the at least two code channels with the at least one distributed physical channel. According to an exemplary aspect of the present invention, there is provided an apparatus comprising an interface configured to communicate with at least another apparatus, and a processor configured to cause the apparatus to perform : receiving at least two code channels with at least one distributed physical channel being distributing over the at least two code channels, and assembling the at least one physical channel from the received at least two code channels.

According to an exemplary aspect of the present invention, there is provided a computer program product including comprising computer- executable computer program code which, when the program is run on a computer (e.g. a computer of an apparatus according to any one of the aforementioned apparatus-related exemplary aspects of the present invention), is configured to cause the computer to carry out the method according to any one of the aforementioned method-related exemplary aspects of the present invention.

Such computer program product may comprise or be embodied as a (tangible) computer-readable (storage) medium or the like on which the computer-executable computer program code is stored, and/or the program may be directly loadable into an internal memory of the computer or a processor thereof.

Advantageous further developments or modifications of the aforementioned exemplary aspects of the present invention are set out in the following.

By way of exemplary embodiments of the present invention, there is provided a code-distributed physical channel definition. More specifically, by way of exemplary embodiments of the present invention, there are provided measures and mechanisms for a code-distributed physical channel definition.

Thus, improvement is achieved by methods, apparatuses and computer program products enabling/realizing a code-distributed physical channel definition.

Brief description of the drawings

In the following, the present invention will be described in greater detail by way of non-limiting examples with reference to the accompanying drawings, in which

Figure 1 shows a schematic diagram of an example of a conventional physical channel definition in a slot format of a code channel, Figure 2 shows a schematic diagram of an example of a code resource utilization of two code channels, for which exemplary embodiments of the present invention are applicable, Figure 3 shows a schematic diagram of an example of a code resource utilization resulting from the code resource utilization according to Figure 2 upon set-up of additional physical channels using the conventional physical channel definition, Figure 4 shows a schematic diagram of an example of a physical channel definition in a slot format of two code channels according to exemplary embodiments of the present invention,

Figure 5 shows a schematic diagram of an example of a code resource utilization resulting from the code resource utilization according to Figure 2 upon set-up of additional physical channels using the physical channel definition according to exemplary embodiments of the present invention,

Figure 6 shows a schematic diagram of a procedure between apparatuses according to exemplary embodiments of the present invention,

Figure 7 shows a schematic diagram of a procedure at an apparatus according to exemplary embodiments of the present invention, and Figure 8 shows a schematic diagram of apparatuses according to exemplary embodiments of the present invention.

Detailed description of drawings and embodiments of the present invention The present invention is described herein with reference to particular non- limiting examples and to what are presently considered to be conceivable embodiments of the present invention. A person skilled in the art will appreciate that the invention is by no means limited to these examples, and may be more broadly applied. It is to be noted that the following description of the present invention and its embodiments mainly refers to specifications being used as non-limiting examples for certain exemplary network configurations and deployments. Namely, the present invention and its embodiments are mainly described in relation to 3GPP specifications being used as non-limiting examples for certain exemplary network configurations and deployments. In particular, a UMTS communication system utilizing CDMA/WCDMA communications is used as a non-limiting example for the applicability of thus described exemplary embodiments. As such, the description of exemplary embodiments given herein specifically refers to terminology which is directly related thereto. Such terminology is only used in the context of the presented non-limiting examples, and does naturally not limit the invention in any way. Rather, any other network configuration or system deployment, etc. may also be utilized as long as compliant with the features described herein.

In particular, the present invention and its embodiments may be applicable in any communication system utilizing code-multiplexed wireless communications, i.e. code channels.

Hereinafter, various embodiments and implementations of the present invention and its aspects or embodiments are described using several variants and/or alternatives. It is generally noted that, according to certain needs and constraints, all of the described variants and/or alternatives may be provided alone or in any conceivable combination (also including combinations of individual features of the various variants and/or alternatives).

According to exemplary embodiments of the present invention, in general terms, there are provided measures and mechanisms for (enabling/realizing) a code-distributed physical channel definition.

In the following, the principles of the present invention and exemplary embodiments thereof are described with reference to an exemplary non- limiting use case. This exemplary non-limiting use case is used for explanatory purposes only, without limiting the general applicability of the present invention and exemplary embodiments thereof (as outlined below).

The exemplary non-limiting use case described in the following relates to uplink closed loop transmit diversity (UL CLTD) as currently under 3GPP specification.

In the UL CLTD mode, a terminal, such as a UE, transmits in the uplink direction using 2 antennas from which the signals are multiplied by coefficients which aim at maximizing the power received at the receiver of the base station or access node, such as a NodeB or eNB. Those coefficients (weights) come from recommendations from the serving base station or access node in the form of PCI (Precoding Indicator) commands. The PCI or PCI command is sent via F-PCICH channel, representing a physical channel, with spreading factor equal to 256 and QPSK modulation. The PCI or PCI command consists of 2 bits, sent as 2 symbols on a code channel, which symbols are located at the same slot position in 2 consecutive slots of the code channel. The PCI bits are repetition encoded, thus one bit of the physical channel forming one QPSK symbol on the code channel. The update period of PCI is equal to 3 slots. Since the PCI transmission for one user (i.e. terminal or UE) consumes two SF256 symbols (i.e. symbols with spreading factor equal to 256) and there are 30 symbols available in a 3- slot period (when assuming that each slot comprises 10 symbols), then theoretically it would be possible to multiplex 15 users on the same code channel, i.e. on the same code, such as the same OVSF code.

Figure 1 shows a schematic diagram of an example of a conventional physical channel definition in a slot format of a code channel, which is in line with the above-outlined scenario in the exemplary UL CLTD case. In Figure 1, four slots of one code channel are illustrated, wherein a grey square denotes a PCI symbol (all of which are destined for a single UE) and a white square denotes an unused symbol, respectively.

Due to the aforementioned convention that the PCI or PCI command will be sent as 2 symbols located at the same slot position in 2 consecutive slots, the PCI symbols in the first and second slots in Figure 1 form a full PCI or PCI command destined for one UE. Due to the PCI update period of 3 slots, a symbol at the same slot position in the third slot in Figure 1 is left unused. The unused symbol in the third slot in Figure 1 cannot be used for the purposes of PCI transmission of the one UE, and it cannot be used for the purposes of PCI transmission of another UE either. This is because, when this unused symbol in the third slot could be used in PCI transmission of another UE, the thus transmitted PCI would necessarily also consume the corresponding symbol in the fourth slot, which is however already reserved. Namely, the PCI update period of 3 slots demands the transmission of the next PCI or PCI command for the one UE starting from this corresponding symbol in the fourth slot. Additionally, the unused symbol in the third slot in Figure 1 cannot be used for a TPC command on the F-DPCH channel either, because according to current 3GPP specifications the TPC is transmitted once per every slot, each time in the same location inside the slot and on the same code channel. Thus, due to the structure of the F-PCICH channel, the loss of one symbol every 3 slots seems to be inevitable. Accordingly, the maximum number of users (i.e. terminals or UEs) for which the F-PCICH channel can be simultaneously sent on the same code channel, e.g. on the same OVSF code, drops to 10 (instead of the 15 users being theoretically servable).

Irrespective of the mode at the terminal side, a base station or access node in a communication system typically serves a plural number of users or UEs. For serving plural terminals, the base station or access node typically utilizes more than one code channel, wherein the utilized code channels exhibit certain resource utilization.

Hereinafter, whenever two or more code channels are assumed to be in use, these plural code channels are illustrated in a slot-aligned manner. Such slot-aligned illustration of Figures 2 to 5 is merely used herein for facilitating a comprehensible description of exemplary embodiments of the present invention and the underlying principles thereof. Accordingly, despite such exemplary and non-limiting illustration, any reference to two or more code channels herein does not require an actual slot-alignment thereof (e.g. in the sense of 3GPP specifications).

Figure 2 shows a schematic diagram of an example of a code resource utilization of two code channels, for which exemplary embodiments of the present invention are applicable. For the exemplary illustration of Figure 2, a resource utilization of two SF256 codes for the purposes of TPC and PCI transmissions is assumed as a non-limiting example. In Figure 2, four slots of two code channels are illustrated, wherein grey squares denote symbols used for TPC and PCI transmissions and white squares denote unused symbols.

Based on such example of resource utilization, a predicted behavior of the base station or access node in question is explained for the case that 6 F- PCICH channels are to be set up additionally. For example, it is assumed that 6 UEs are be reconfigured from a single-antenna transmission mode to a multiple-antenna transmission mode such as the UL CLTD mode. If so, there is a need to set up one F-PCICH channel for each one of the UEs to be reconfigured, i.e. to set up 6 additional F-PCICH channels in total. Any one of these F-PCICH channels to be set up has to comply with the aforementioned provisions.

Under such exemplary circumstances, the base station or access node will set up the new channels by establishing resource utilization as illustrated in Figure 3. Figure 3 shows a schematic diagram of an example of a code resource utilization resulting from the code resource utilization according to Figure 2 upon set-up of additional physical channels using the conventional physical channel definition. In Figure 3, four slots of three code channels are illustrated, wherein grey squares denote symbols used for TPC and PCI transmissions and white squares denote unused symbols (corresponding to the underlying code resource utilization according to Figure 2), and squares with numbers denote symbols used for the additional channels being set up. Accordingly, each one of the six additional channels is represented by a set of squares bearing the same number ranging between 1 and 6. Each square with a certain number thus denotes a PCI symbol, which corresponds to a PCI or PCI command destined for one of the six UEs being reconfigured.

As evident from Figure 3, assuming the present example on the basis of the code resource utilization according to Figure 2, the base station or access node is forced to use the third code channel or OVSF code for realizing an appropriate PCI transmission as required. This is because the code resource utilization according to Figure 2 is not capable of incorporating the required symbol allocations in accordance with the conventional physical channel definition. This is all the more the case, since the reconfiguration of other UEs' channels (F-DPCH and/or F-PCICH), whenever a new UE appears or is reconfigured, is considered as unlikely (which is why the previously prevailing code resource utilization is to be assumed to be persist and, thus, is to be taken as a basis). Moreover, as the six additional channels are not sufficient for using the full capacity of the third code channels, such need to establish an additional code channel leads to even more available symbols being left unused.

In view of the above, referring to Figures 1 and 3, it is evident that resource reservations on code channels suffered from deficiencies in resource efficiency in that available symbols (i.e. resources) are forced to be left unused in order to comply with the existing conventions and physical channel definition.

According to exemplary embodiments of the present invention, more efficient resource utilization is enabled, while complying with the existing conventions and physical channel definition, as explained below. Figure 4 shows a schematic diagram of an example of a physical channel definition in a slot format of two code channels according to exemplary embodiments of the present invention. In Figure 4, four slots of two code channel are illustrated, wherein a grey square denotes a PCI symbol (all of which are destined for a single UE) and a white square denotes an unused symbol, respectively.

Due to the aforementioned convention that the PCI or PCI command will be sent as 2 symbols located at the same slot position in 2 consecutive slots, the PCI symbols in the first and second slots in Figure 4 form a full PCI or PCI command destined for one UE. Yet, in contrast to the conventional physical channel definition, the 2 symbols in 2 consecutive slots are located on different code channels. As evident from Figure 4, the PCI symbols corresponding to the same physical channel are arranged such that they do not overlap with each other in the time domain (i.e. in the horizontal direction). Thus, the distribution of any physical channel onto plural code channels is done in a non-overlapping manner in the time domain, i.e. results in non-overlapping resource utilization in the time domain.

As shown in the example of Figure 4, a single PCI or PCI command (destined for a single user or terminal) is sent in a distributed manner on two different code channels or e.g. OVSF codes, but still remains the same physical channel. Namely, the first bit of the PCI or PCI command is sent as (or allocated to) a symbol on a code channel or e.g. OVSF code which is different from the code channel or e.g. OVSF code on which the second bit of the PCI or PCI command is being sent (or allocated to). The full PCI or PCI command is formed from both bits despite the fact that they are received on different code channels or e.g. OVSF codes.

That is to say, in a physical channel definition according to exemplary embodiments of the present invention, the single physical channel, i.e. the corresponding code channel symbols thereof, is distributed over (at least) two code channels or e.g. OVSF codes. Stated in other words, according to exemplary embodiments of the present invention, a physical channel is not defined on a single code channel or by a single code, such as a single OVSF code. According to exemplary embodiments of the present invention, it may be selectively determined whether to use the physical channel definition according to exemplary embodiments of the present invention, as illustrated in Figure 4, or the conventional physical channel definition, as illustrated in Figure 1. In the present example, a base station or access node, for mapping one or more F-PCICH channels to one or more code channels, can choose to either allocate the PCI symbols of a physical channel on the same code channel or e.g. OVSF code, as in the conventional physical channel definition according to Figure 1, or to allocate the PCI symbols of a physical channel on different code channels or e.g. OVSF codes, as in the physical channel definition according to Figure 4. When applying such selective usage of different physical channel definitions by a base station or access node, the base station or access node may notify the terminal or UE accordingly so as to inform the terminal or UE about the physical channel definition being used at a certain time, i.e. for a certain transmissions.

For making a decision in this regard, the base station or access node may evaluate the resource utilization, i.e. the (structure or distribution of) unused symbols of each one of available code channels or e.g. OVSF codes (e.g. the two code channels according to Figure 2), to determine whether it is feasible to allocate the bits of the PCI or PCI command of all F-PCICH channels to be allocated to one of the available code channels or e.g. OVSF codes. When such determination is positive, the bits of the PCI or PCI command of all F-PCICH channels to be allocated are allocated to one of the available code channels or e.g. OVSF codes, while the bits of the PCI or PCI command of all F-PCICH channels to be allocated are allocated to more than one of the available code channels or e.g. OVSF codes when the determination is negative.

While the beneficial effects of exemplary embodiments of the present invention are not necessarily evident from the illustration of Figure 4, they will be more evident from the illustration of Figure 5 and the associated description with respect to the example used above.

According to exemplary embodiments of the present invention, under the exemplary circumstances assumed above for the example according to Figure 3, the base station or access node will set up the new channels by establishing resource utilization as illustrated in Figure 5.

Figure 5 shows a schematic diagram of an example of a code resource utilization resulting from the code resource utilization according to Figure 2 upon set-up of additional physical channels using the physical channel definition according to exemplary embodiments of the present invention.

In Figure 5, four slots of two code channels are illustrated, wherein grey squares denote symbols used for TPC and PCI transmissions and white squares denote unused symbols (corresponding to the underlying code resource utilization according to Figure 2), and squares with numbers denote symbols used for the additional channels being set up. Accordingly, each one of the six additional channels is represented by a set of squares bearing the same number ranging between 1 and 6. Each square with a certain number thus denotes a PCI symbol, which corresponds to a PCI or PCI command destined for one of the six UEs being reconfigured.

In the physical channel definition according to exemplary embodiments of the present invention, as evident from both Figures 4 and 5, the PCI symbols, i.e. the code channel symbols corresponding to the bits of a PCI or PCI command of a single physical channel or user may be allocated such that one or more of the following conditions is satisfied. Namely, the PCI symbols may be allocated such that the PCI symbols are located at an equivalent (e.g. the same) slot position in slots of a slot format of the code channels used, and/or the PCI symbols in consecutive slots of a slot format of the code channels used are located on different code channels, and/or the PCI symbols corresponding to consecutive bits of the PCI or PCI command of the physical channel are located on different code channels. Further, in the physical channel definition according to exemplary embodiments of the present invention, a different timing can be used for (the allocation of) different physical channels. As evident from Figure 5, referring to the first full PCI or PCI command being illustrated in Figure 5, the timing of the F-PCICH channels 2 and 5 is such that their PCI symbols are transmitted in slots 1 and 2, 4 and 5, and so on, while the timing of the F-PCICH channel 4 and 6 are such that their PCI symbols are transmitted in slots 2 and 3, 5 and 6, and so on, and the timing of the F-PCICH channels 1 and 3 is such that their PCI symbols are transmitted in slots 3 and 4, 6 and 7, and so on.

Still further, in the physical channel definition according to exemplary embodiments of the present invention, the distribution of all physical channels onto plural code channels is done in a non-overlapping manner in the time domain, i.e. results in non-overlapping resource utilization in the time domain. As evident from Figure 5, the PCI symbols corresponding to the six F-PCICH channels are arranged such that none of them overlaps with any one of the others in the time domain (i.e. in the horizontal direction).

As a result of using the physical channel definition according to exemplary embodiments of the present invention, the base station or access node succeeded in utilizing the blank fields, i.e. the unused symbols in the two code channels according to resource utilization of Figure 2.

As evident from Figure 5, assuming the present example on the basis of the code resource utilization according to Figure 2, the base station or access node is not forced to use a third code channel or OVSF code for realizing an appropriate PCI transmission as required, but rather succeeds in incorporating the required symbols in accordance with the existing provisions within the two code channels already being established.

Accordingly, as evident from a comparison of Figures 3 and 5, the resource utilization according to exemplary embodiments of the present invention is superior in terms of resource efficiency, i.e. the resource utilization can be done in more efficient manner, when compared with that according to conventional techniques. From the perspective of the base station or access node, a gain in resource reservation for allocating one or more physical channels is achievable.

Another exemplary use case for the present invention and its embodiments is related to interference averaging. Under some circumstances (such as multipath channel conditions or interference from other transmissions) it may happen that a certain code channel suffers from a higher than average interference or self interference. A physical channel allocated to that code channel may then e.g. require a higher transmit power to ensure an appropriate reception quality or it may suffer a poor reception quality. In such a case, code-distributed physical channel transmission can be applied as a means for reducing the effect of interference by averaging over at least two code channels. That is to say, at least one physical channel may be distributed over the at least two code channels for enabling interference averaging thereof.

While the above description focuses on the transmission side, i.e. an entity performing resource allocation or channel mapping, it is understood for a skilled person that the reception side, i.e. an entity receiving the thus allocated resource or the thus mapped channels, is to be (or, at least, may be) configured accordingly. At the reception side, reception of the at least two code channels with the distributed physical channel/s is feasible, as the transmissions (relating to a physical channel) on different code channels occur at different times, i.e. in non-overlapping resource utilization in the time domain or temporally displaced/shifted code channel symbols, due to the equivalent slot position of corresponding code channel symbols. In the following, the principles of the present invention and exemplary embodiments thereof are described in a more general manner.

Figure 6 shows a schematic diagram of a procedure between apparatuses according to exemplary embodiments of the present invention. The thus illustrated procedure may be carried out in cooperation between a transmission point and a reception point, with transmission and reception sides being defined in view of the communication direction of the code channel/s carrying the physical channel/s. In view of the above example referring to a downlink communication, the transmission point may be a base station or access node of a communication system and the reception point may be a terminal connecting to the communication system. However, exemplary embodiments of the present invention are equally applicable to an uplink communication, wherein in such case the transmission point may be a terminal connecting to a communication system and the reception point may be a base station or access node of the communication system.

As shown in Figure 6, a corresponding procedure at the transmission point according to exemplary embodiments of the present invention comprises an operation (610) of distributing at least one physical channel over at least two code channels, and an operation (620) of transmitting the at least two code channels with the at least one distributed physical channel. The operation of physical channel distribution may comprise an operation of allocating data elements of the at least one physical channel to symbols of the at least two code channels.

As shown in Figure 6, a corresponding procedure at the reception point according to exemplary embodiments of the present invention comprises an operation (620) of receiving at least two code channels with at least one distributed physical channel being distributing over the at least two code channels, and an operation (630) of assembling the at least one physical channel from the received at least two code channels, i.e. forming the at least one physical channel from corresponding symbols of the at least two code channels.

As described above, the communication operation 620 according to Figure 6 may basically comprise a communication of the at least two code channels from the transmission point to the reception point. Further, the communication operation 620 according to Figure 6 may comprise a communication of information about the distribution of the at least one physical channel to the at least two code channels from the transmission point to the reception point. Namely, in addition to the physical channel as such, signaling information may be conveyed so as to notify the reception point of the code channel arrangements/allocations, thereby enabling a corresponding adaptation/configuration for facilitating a proper receipt of the code channel transmission at the reception point. According to exemplary embodiments of the present invention, the code channel transmission and the signaling information transmission may be accomplished in a common communication or in separate communications. For example, the signaling information may be transmitted within the at least two code channels, or the signaling information transmission may be accomplished by way of a signaling protocol-related communication, such as e.g. a RRC communication.

Figure 7 shows a schematic diagram of a procedure at an apparatus according to exemplary embodiments of the present invention. The thus illustrated procedure may be carried out at the transmission point according to Figure 6.

As shown in Figure 7, a corresponding procedure at the transmission point according to exemplary embodiments of the present invention comprises an operation (710) of evaluating unused symbols of each one of the at least two code channels to determine (720) whether it is feasible to allocate the data elements of the at least one physical channel to one of the at least two code channels. When the determination (720) is positive, the procedure continues with an operation (740) in which the data elements of the at least one physical channel are allocated to unused symbols of the one of the at least two code channels, i.e. by using a non-distributed physical channel definition. When the determination (720) is negative, the procedure continues with an operation (730) in which the data elements of the at least one physical channel are allocated to unused symbols of the at least two code channels, i.e. by using a distributed physical channel definition. By way of the functionality according to Figure 7, a transmission point according to exemplary embodiments of the present invention may be enabled to operate in two optional/alternative ways. Thereby, a transmission point according to exemplary embodiments of the present invention may be enabled to perform code channel utilization or physical channel allocation in the non-distributed manner (e.g. for legacy users or UEs) and/or to perform code channel utilization or physical channel allocation in the distributed manner (e.g. for modern users or UEs).

As evident from the above, exemplary embodiments of the present invention basically include that a single physical channel (i.e. each one of one or more physical channels to be communicated) may span, i.e. may be distributed, over more than one code channel or code.

Accordingly, exemplary embodiments of the present invention enable to avoid a loss/waste of available resources, especially when a piece of data exhibits an update period of a slot number larger than a number of data elements of the piece of data. That is to say, exemplary embodiments of the present invention enable to avoid that only less pieces of data than theoretically possible could be communicated on a code channel, i.e. only less physical channels than theoretically possible could be mapped/allocated to a code channel, and /or that an additional code channel is required to be used/established for enabling communication of a desired number of data elements, i.e. mapping/allocation of a desired number of physical channels.

As mentioned above, exemplary embodiments of the present invention are not restricted to the above example which is exemplarily used for describing the principles thereof, but are equally applicable to other use cases or scenarios.

For exemplary embodiments of the present invention, the following may apply (with respect to the above example). A physical channel could for example be, but is not restricted to, a F-PCICH channel for communicating a PCI or PCI command. Yet, it may also be e.g. a F-DPCH channel for communicating a TPC. Generally, a physical channel may be any channel defining data to be physically communicated from one entity to another entity in a communication system.

A code channel could for example be, but is not restricted to, a CDMA/WCDMA code channel. Generally, a code channel may be any communication channel defined by a predetermined code, said predetermined code including a spreading factor or an orthogonal variable spreading factor or any code capable of defining a CDMA/WCDMA communication channel.

A data element of a physical channel could for example be, but is not restricted to, a bit, such as a bit of a piece of data to be communicated. Yet, it may also be e.g. a byte or any other data unit (depending e.g. on encoding type or the like).

A piece of data to be communicated could for example be, but is not restricted to, a PCI or PCI command. Yet, it may also be e.g. any other command relating to transmit power setting or the like, such as e.g. in a closed loop transmit diversity scheme in both uplink or downlink direction.

The piece of data could for example exhibit an update period of a number larger than a number of data elements of the piece of data, but is not restricted to such configuration.

A symbol of a code channel could for example be, but is not restricted to, a QPSK symbol. Generally, a symbol of a code channel may be any modulation symbol configured for carrying data to be communicated on/by the code channel.

A communication system could for example be, but is not restricted to, a CDMA/WCDMA system, such as e.g. an UMTS CDMA/WCDMA system. Generally, a communication system may be any communication system with code- multiplexed communications.

The above-described procedures and functions may be implemented by respective functional elements, processors, or the like, as described below.

While in the foregoing exemplary embodiments of the present invention are described mainly with reference to methods, procedures and functions, corresponding exemplary embodiments of the present invention also cover respective apparatuses, network nodes and systems, including both software and/or hardware thereof.

Respective exemplary embodiments of the present invention are described below referring to Figure 8, while for the sake of brevity reference is made to the detailed description of respective corresponding schemes, methods and operations according to Figures 4 to 7.

In Figure 8 below, the solid line blocks are basically configured to perform respective operations as described above. The entirety of solid line blocks are basically configured to perform the methods and operations as described above, respectively. With respect to Figure 8, it is to be noted that the individual blocks are meant to illustrate respective functional blocks implementing a respective function, process or procedure, respectively. Such functional blocks are implementation-independent, i.e. may be implemented by means of any kind of hardware or software, respectively. The arrows and lines interconnecting individual blocks are meant to illustrate an operational coupling there-between, which may be a physical and/or logical coupling, which on the one hand is implementation- independent (e.g. wired or wireless) and on the other hand may also comprise an arbitrary number of intermediary functional entities not shown. The direction of arrow is meant to illustrate the direction in which certain operations are performed and/or the direction in which certain data is transferred. Further, in Figure 8, only those functional blocks are illustrated, which relate to any one of the above-described methods, procedures and functions. A skilled person will acknowledge the presence of any other conventional functional blocks required for an operation of respective structural arrangements, such as e.g. a power supply, a central processing unit, respective memories or the like. Among others, memories are provided for storing programs or program instructions for controlling the individual functional entities to operate as described herein. Figure 8 shows a schematic diagram of apparatuses according to exemplary embodiments of the present invention.

In view of the above, the thus described apparatuses 10 and 20 are suitable for use in practicing the exemplary embodiments of the present invention, as described herein.

The thus described apparatus 10 may represent a (part of a) transmission point and thus described apparatus 20 may represent a (part of a) reception point. According to exemplary embodiments of the present invention, the transmission point may be a base station or access node of a communication system and the reception point may be a terminal connecting to the communication system (when referring to a downlink communication), and/or the transmission point may be a terminal connecting to a communication system and the reception point may be a base station or access node of the communication system (when referring to a downlink communication).

The thus described apparatus 10 may be configured to perform a procedure and/or exhibit a functionality as described in conjunction with any one of Figures 4 to 7, and thus described apparatus 20 may be configured to perform a procedure and/or exhibit a functionality as described in conjunction with any one of Figures 4 to 6.

As indicated in Figure 8, according to exemplary embodiments of the present invention, each of the apparatuses comprises a processor 11/22, a memory 12/22 and an interface 13/23, which are connected by a bus 14/24 or the like, and the apparatuses may be connected via a link A.

The processor 11/21 and/or the interface 13/23 may also include a modem or the like to facilitate communication over a (hardwire or wireless) link, respectively. The interface 13/23 may include a suitable transceiver coupled to one or more antennas or communication means for (hardwire or wireless) communications with the linked or connected device(s), respectively. The interface 13/23 is generally configured to communicate with at least one other apparatus, i.e. the interface thereof.

The memory 12/22 may store respective programs assumed to include program instructions or computer program code that, when executed by the respective processor, enables the respective electronic device or apparatus to operate in accordance with the exemplary embodiments of the present invention.

In general terms, the respective devices/apparatuses (and/or parts thereof) may represent means for performing respective operations and/or exhibiting respective functionalities, and/or the respective devices (and/or parts thereof) may have functions for performing respective operations and/or exhibiting respective functionalities.

When in the subsequent description it is stated that the processor (or some other means) is configured to perform some function, this is to be construed to be equivalent to a description stating that a (i.e. at least one) processor or corresponding circuitry, potentially in cooperation with computer program code stored in the memory of the respective apparatus, is configured to cause the apparatus to perform at least the thus mentioned function. Also, such function is to be construed to be equivalently implementable by specifically configured circuitry or means for performing the respective function (i.e. the expression "processor configured to [cause the apparatus to] perform xxx-ing" is construed to be equivalent to an expression such as "means for xxx-ing"). According to exemplary embodiments of the present invention, the apparatus 10 or its processor 11 is configured to perform distributing at least one physical channel over at least two code channels, and transmitting the at least two code channels with the at least one distributed physical channel.

According to exemplary embodiments of the present invention, the apparatus 10 or its processor 11 may be configured to perform one or more of:

- allocating data elements of the at least one physical channel to symbols of the at least two code channels,

- allocating data elements of the at least one physical channel to symbols of the at least two code channels, wherein the data elements of a physical channel are allocated to symbols of the at least two code channels the symbols are displaced with respect to each other in the time domain, or the symbols are displaced with respect to each other and with respect to symbols corresponding to one or more other physical channels in the time domain,

- allocating data elements of the at least one physical channel to symbols of the at least two code channels, wherein the data elements of a physical channel are allocated to symbols of the at least two code channels such that the symbols are located at an equivalent slot position in slots of a slot format of the at least two code channels, and/or the symbols in consecutive slots of a slot format of the at least two code channels are located on different code channels, and/or the symbols corresponding to consecutive data elements of said physical channel are located on different code channels,

- evaluating unused symbols of each one of the at least two code channels to determine whether it is feasible to allocate the data elements of the at least one physical channel to one of the at least two code channels, wherein the processor is configured to cause the apparatus to allocate the data elements of the at least one physical channel to unused symbols of the one of the at least two code channels, when the determination is positive, and wherein the processor is configured to cause the apparatus to allocate the data elements of the at least one physical channel in a distributed manner to unused symbols of the at least two code channels, when the determination is negative, and

- transmitting information about the distribution of the at least one physical channel to the at least two code channels towards a reception point of the code channel transmission.

According to exemplary embodiments of the present invention, the apparatus 20 or its processor 21 is configured to perform receiving at least two code channels with at least one distributed physical channel being distributing over the at least two code channels, and assembling the at least one physical channel from the received at least two code channels.

According to exemplary embodiments of the present invention, one or more of the following may be the case:

- symbols of the at least two code channels are allocated to data elements of the at least one physical channel,

- the apparatus 20 or its processor 21 is configured to cause the apparatus to perform assembling the symbols corresponding to data elements of the at least one physical channel from the received at least two code channels, and

- the apparatus 20 or its processor 21 is configured to cause the apparatus to perform receiving information about the distribution of the at least one physical channel to the at least two code channels from a transmission point of the code channel transmission.

According to exemplarily embodiments of the present invention, the processor 11/21, the memory 12/22 and the interface 13/23 may be implemented as individual modules, chips, chipsets, circuitries or the like, or one or more of them can be implemented as a common module, chip, chipset, circuitry or the like, respectively.

According to exemplarily embodiments of the present invention, a system may comprise any conceivable combination of the thus depicted devices/apparatuses and other network elements, which are configured to cooperate as described above. In general, it is to be noted that respective functional blocks or elements according to above-described aspects can be implemented by any known means, either in hardware and/or software, respectively, if it is only adapted to perform the described functions of the respective parts. The mentioned method steps can be realized in individual functional blocks or by individual devices, or one or more of the method steps can be realized in a single functional block or by a single device. Generally, any method step is suitable to be implemented as software or by hardware without changing the idea of the present invention. Such software may be software code independent and can be specified using any known or future developed programming language, such as e.g. Java, C++, C, and Assembler, as long as the functionality defined by the method steps is preserved. Such hardware may be hardware type independent and can be implemented using any known or future developed hardware technology or any hybrids of these, such as MOS (Metal Oxide Semiconductor), CMOS (Complementary MOS), BiMOS (Bipolar MOS), BiCMOS (Bipolar CMOS), ECL (Emitter Coupled Logic), TTL (Transistor-Transistor Logic), etc., using for example ASIC (Application Specific IC (Integrated Circuit)) components, FPGA (Field-programmable Gate Arrays) components, CPLD (Complex Programmable Logic Device) components or DSP (Digital Signal Processor) components. A device/apparatus may be represented by a semiconductor chip, a chipset, or a (hardware) module comprising such chip or chipset; this, however, does not exclude the possibility that a functionality of a device/apparatus or module, instead of being hardware implemented, be implemented as software in a (software) module such as a computer program or a computer program product comprising executable software code portions for execution/being run on a processor. A device may be regarded as a device/apparatus or as an assembly of more than one device/apparatus, whether functionally in cooperation with each other or functionally independently of each other but in a same device housing, for example. Apparatuses and/or means or parts thereof can be implemented as individual devices, but this does not exclude that they may be implemented in a distributed fashion throughout the system, as long as the functionality of the device is preserved. Such and similar principles are to be considered as known to a skilled person.

Software in the sense of the present description comprises software code as such comprising code means or portions or a computer program or a computer program product for performing the respective functions, as well as software (or a computer program or a computer program product) embodied on a tangible medium such as a computer-readable (storage) medium having stored thereon a respective data structure or code means/portions or embodied in a signal or in a chip, potentially during processing thereof.

The present invention also covers any conceivable combination of method steps and operations described above, and any conceivable combination of nodes, apparatuses, modules or elements described above, as long as the above-described concepts of methodology and structural arrangement are applicable.

In view of the above, there are provided measures for code-distributed physical channel definition. Such measures may exemplarily comprise distributing at least one physical channel over at least two code channels, and transmitting the at least two code channels with the at least one distributed physical channel. The physical channel distribution may exemplarily comprises an allocation of data elements of the at least one physical channel to (unused) symbols of the at least two code channels. The measures according to exemplary embodiments of the present invention may be applied for any kind of network environment, particularly in any kind of W-/CDMA-based communication system, such as for example for those in accordance with 3GPP RAN2/RAN3 standards and/or UMTS or 3GPP LTE standards of release 10/11/12/... (LTE-Advanced and its evolutions). Even though the invention is described above with reference to the examples according to the accompanying drawings, it is to be understood that the invention is not restricted thereto. Rather, it is apparent to those skilled in the art that the present invention can be modified in many ways without departing from the scope of the inventive idea as disclosed herein.

List of acronyms and abbreviations 3GPP Third Generation Partnership Project

CDMA Code Division Multiple Access

CLTD Closed Loop Transmit Diversity

DL Downlink

eNB evolved NodeB

F-DPCH Fractional Dedicated Physical Channel

F-PCICH Fractional Precoding Indicator Channel

OVSF Orthogonal Variable Spreading Factor

LTE Long Term Evolution

PCI Precoding Indicator

QPSK Quadrature Phase Shift Keying

RRC Radio Resource Control

SF Spreading Factor

TPC Transmit Power Command

UE User Equipment

UL Uplink

UMTS Universal Mobile Telecommunications System

WCDMA Wideband CDMA

Claims

1. A method comprising

distributing at least one physical channel over at least two code channels, and

transmitting the at least two code channels with the at least one distributed physical channel.

2. The method according to claim 1, wherein the physical channel distribution comprises

allocating data elements of the at least one physical channel to symbols of the at least two code channels.

3. The method according to claim 2, wherein the data elements of a physical channel are allocated to symbols of the at least two code channels such that

the symbols are displaced with respect to each other in the time domain, or

the symbols are displaced with respect to each other and with respect to symbols corresponding to one or more other physical channels in the time domain.

4. The method according to claim 2 or 3, wherein the data elements of a physical channel are allocated to symbols of the at least two code channels such that

the symbols are located at an equivalent slot position in slots of a slot format of the at least two code channels, and/or

the symbols in consecutive slots of a slot format of the at least two code channels are located on different code channels, and/or

the symbols corresponding to consecutive data elements of said physical channel are located on different code channels.

5. The method according to any one of claims 2 to 4, further comprising evaluating unused symbols of each one of the at least two code channels to determine whether it is feasible to allocate the data elements of the at least one physical channel to one of the at least two code channels, wherein the data elements of the at least one physical channel are allocated to unused symbols of the one of the at least two code channels, when the determination is positive, and

wherein the data elements of the at least one physical channel are allocated in a distributed manner to unused symbols of the at least two code channels, when the determination is negative.

6. The method according to any one of claims 1 to 5, further comprising transmitting information about the distribution of the at least one physical channel to the at least two code channels towards a reception point of the code channel transmission.

7. The method according to any one of claims 1 to 6, wherein

a code channel is a communication channel defined by a predetermined code, said predetermined code including a spreading factor or an orthogonal variable spreading factor or any code capable of defining a code division multiple access or wideband code division multiple access communication channel, and/or

the at least two code channels are defined by different predetermined codes, respectively, and/or

the at least two code channels have a slot format in which each slot comprises a predetermined number of symbols, and/or

the at least one physical channel is for communicating a piece of data with an update period of a number larger than a number of data elements of the piece of data, and/or

the at least one physical channel comprises a fractional precoding indicator channel for communicating a precoding indicator or a precoding indicator command, and/or

the at least one physical channel is for communicating a command relating to transmit power setting in a closed loop transmit diversity scheme, and/or the at least one physical channel is distributed over the at least two code channels for enabling interference averaging thereof.

8. The method according to any one of claims 1 to 7, wherein

the method is operable in a communication system in accordance with code division multiple access or wideband code division multiple access, and/or

the method is operable at or by a base station or access node of a communication system, and the at least one physical channel is destined for a terminal connecting to the communication system, and/or

the method is operable at or by a terminal connecting to a communication system, and the at least one physical channel is destined for a base station or access node of the communication system.

9. A method comprising

receiving at least two code channels with at least one distributed physical channel being distributing over the at least two code channels, and assembling the at least one physical channel from the received at least two code channels.

10. The method according to claim 9, wherein

symbols of the at least two code channels are allocated to data elements of the at least one physical channel, and

the symbols corresponding to data elements of the at least one physical channel are assembled from the received at least two code channels.

11 The method according to claim 9 or 10, further comprising

receiving information about the distribution of the at least one physical channel to the at least two code channels from a transmission point of the code channel transmission.

12. The method according to any one of claims 9 to 11, wherein

the at least one physical channel is for communicating a command relating to transmit power setting in a closed loop transmit diversity scheme, and/or

the at least one physical channel is distributed over the at least two code channels for enabling interference averaging thereof.

13. The method according to any one of claims 9 to 12, wherein

the method is operable at or by a terminal connecting to a communication system, and the at least one physical channel originates from a base station or access node of the communication system, and/or the method is operable at or by a base station or access node of a communication system, and the at least one physical channel originates from a terminal connecting to the communication system.

14. An apparatus comprising

an interface configured to communicate with at least another apparatus, and

a processor configured to cause the apparatus to perform : distributing at least one physical channel over at least two code channels, and

15. The apparatus according to claim 14, wherein the processor is configured to cause the apparatus to perform :

16. The apparatus according to claim 15, wherein the processor is configured to cause the apparatus to allocate the data elements of a physical channel to symbols of the at least two code channels such that the symbols are displaced with respect to each other in the time domain, or

17. The apparatus according to claim 15 or 16, wherein the processor is configured to cause the apparatus to allocate the data elements of a physical channel to symbols of the at least two code channels such that the symbols are located at an equivalent slot position in slots of a slot format of the at least two code channels, and/or

18. The apparatus according to any one of claims 15 to 17, wherein the processor is configured to cause the apparatus to perform :

evaluating unused symbols of each one of the at least two code channels to determine whether it is feasible to allocate the data elements of the at least one physical channel to one of the at least two code channels, wherein the processor is configured to cause the apparatus to allocate the data elements of the at least one physical channel to unused symbols of the one of the at least two code channels, when the determination is positive, and

wherein the processor is configured to cause the apparatus to allocate the data elements of the at least one physical channel in a distributed manner to unused symbols of the at least two code channels, when the determination is negative.

19. The apparatus according to any one of claims 14 to 18, wherein the processor is configured to cause the apparatus to perform :

transmitting information about the distribution of the at least one physical channel to the at least two code channels towards a reception point of the code channel transmission.

20. The apparatus according to any one of claims 14 to 19, wherein

21. The apparatus according to any one of claims 14 to 20, wherein

the apparatus is operable in a communication system in accordance with code division multiple access or wideband code division multiple access, and/or

the apparatus is operable as or at a base station or access node of a communication system, and the at least one physical channel is destined for a terminal connecting to the communication system, and/or

the apparatus is operable as or at a terminal connecting to a communication system, and the at least one physical channel is destined for a base station or access node of the communication system.

22. An apparatus comprising

an interface configured to communicate with at least another apparatus, and

a processor configured to cause the apparatus to perform :

23. The apparatus according to claim 22, wherein

the processor is configured to cause the apparatus to perform assembling the symbols corresponding to data elements of the at least one physical channel from the received at least two code channels.

24. The apparatus according to claim 22 or 23, wherein the processor is configured to cause the apparatus to perform :

25. The apparatus according to any one of claims 22 to 24, wherein a code channel is a communication channel defined by a predetermined code, said predetermined code including a spreading factor or an orthogonal variable spreading factor or any code capable of defining a code division multiple access or wideband code division multiple access communication channel, and/or

the at least two code channels have a slot format in which each slot comprising a predetermined number of symbols, and/or

26. The apparatus according to any one of claims 22 to 25, wherein

the apparatus is operable as or at a terminal connecting to a communication system, and the at least one physical channel originates from a base station or access node of the communication system, and/or the apparatus is operable as or at a base station or access node of a communication system, and the at least one physical channel originates from a terminal connecting to the communication system.

27. A computer program product comprising computer-executable computer program code which, when the program is run on a computer, is configured to cause the computer to carry out the method according to any one of claims 1 to 13.

28. The computer program product according to claim 27, wherein the computer program product comprises a computer-readable medium on which the computer-executable computer program code is stored, and/or wherein the program is directly loadable into an internal memory of the processor.