WO2013063812A1

WO2013063812A1 - Utilization of blind detection resources in carrier aggregation scenarios

Info

Publication number: WO2013063812A1
Application number: PCT/CN2011/081842
Authority: WO
Inventors: Wei Bai; Erlin Zeng; Haiming Wang; Jing HAN; Wei Hong; Chunyan Gao
Original assignee: Renesas Mobile Corporation
Priority date: 2011-11-06
Filing date: 2011-11-06
Publication date: 2013-05-10

Abstract

The present invention proposes methods for devices, devices and computer program products for devices in relation to a communication module configured for communication, based on time slots, in a carrier aggregation mode aggregating a primary and at least one secondary carrier. Receiving a transmission divided into a plurality of sections comprising predetermined first sections and predetermined second sections, said predetermined first and second sections containing control data, is performed. It is determined whether at least a part of said predetermined first and second sections is not to be checked. Based on the determination result, a first and second number are set. It is checked for the first number of predetermined first sections and for the second number of predetermined second sections, whether said sections contain control data intended for the device itself.

Description

UTILIZATION OF BLIND DETECTION RESOURCES IN CARRIER AGGREGATION SCENARIOS

Field of the invention

The present invention relates to flexible utilization of blind detection resources for cell specific search space and UE specific search space in carrier aggregation scenarios. More specifically, the present invention relates to methods and devices configured to utilize blind detection resources in carrier aggregation scenarios.

Background

Mobile data transmission and data services are constantly making progress. With the increasing penetration of such services, a need for increased bandwidth for conveying the data is emerging . One currently favored technical solution to achieve this increased bandwidth is known as carrier aggregation (CA). Carrier aggregation affords increased bandwidth providable to a terminal like a User Equipment (UE). To achieve this effect, multiple carriers known as component carriers (CC) are aggregated .

Generally, one CC serves as a primary carrier. The primary carrier represents the frequency block, on which the primary cell operates. The primary cell is the cell, in which the UE performs the initial connection establishment procedure and in which essential control information are communicated . Once such initial connection is established, the UE may connect to further cells, known as secondary cells. The secondary cells operate on secondary carriers which represent further frequency blocks. In a CA, one primary carrier and at least one secondary carrier are aggregated to form coexistent primary and secondary cells.

CA includes contiguous aggregation of adjacent carriers and non-contiguous aggregation, wherein the respective carriers are not adjacent to each other. Such non-contiguous aggregation can be realized with component carriers of one frequency band (Intra-band non-contiguous aggregation) or with component carriers of two or more frequency bands (Inter-band noncontiguous aggregation). On the field of mobile data transmission, currently, a system known as Long Term Evolution (LTE) is being further developed. The following explanation is performed on the basis of LTE only as an example. In this system, a terminal as a user equipment, i.e. a UE communicates with a base station like an evolved Node B, i.e. an eNodeB (eNB).

In LTE Rel-10, only intra-band carrier aggregation is included for uplink direction and only one timing advance (TA) is necessary. However, for LTE Rel-11 inter-band carrier aggregation and further features like radio remote head (RRH) and the provision of repeaters are planned. RRHs are radio units remote from the controlling, actual base station, where a base station may control more than one RRHs. When a UE communicates with an eNB and a RRH at different locations, or more general, with more than one receiving stations at different locations, the distances between the UE and each of the multiple receiving stations respectively may be different and thus different propagation delays may occur. Further, signals transmitted on two different component carriers of bands far apart from each other may be liable to different propagation delays. This introduces the necessity of multiple timing advance for LTE Rel-11. The timing of uplink transmissions is to be controlled so that those transmissions can be received from the eNodeB within a scheduled time slot. If a transmission arrives beyond the scheduled time slot, interference with transmissions of further UEs may appear. Since a distance between an UE and an eNodeB and other conditions affect signal propagation delays, the timing of said uplink transmissions have to be adjusted.

In order to compensate the propagation delay, a mechanism known as timing advance by which the uplink transmission timing at the UE is set earlier than the expected timing at the eNodeB, is deployed . The timing advance procedure in LTE is divided into initial timing advance and timing advance updates. The initial TA is used after the UE synchronizes its receiver to the downlink transmissions of the eNodeB and is set by means of the random access procedure: the eNodeB can estimate the uplink timing from the random access preamble and sends timing advance command including the time offset by which the UE should advance its transmission within a random access response (RAR) message.

A further new technique has been introduced with LTE Rel-11 named timing advance group (TA group). A TA group is defined as a set of aggregated carriers which share the same TA and timing reference.

For LTE Rel-11, it is planned to implement the multiple timing advance mechanism according to the originally timing advance mechanism by using the Random Access Channel (RACH). To achieve the necessary information for the one or more secondary carriers, a RACH preamble is to be transmitted using the Physical Random Access Channel PRACH of the secondary carrier if the one ore more secondary carriers are not in the TA group of the primary cell . The known cross-carrier scheduling allows assigning radio resources on a CC via control information on another CC. Thus, when a random access preamble (in LTE specification known as Msg l) is transmitted on one CC, the corresponding RAR message (in LTE specification known as Msg2) may be transmitted on another CC.

Such RAR and other control information are transmitted using a physical downlink control channel (PDCCH) in terms of downlink control information (DCI). A DCI message contains one of: downlink scheduling information, uplink scheduling information and uplink power control information.

Per subframe many DCIs are transmitted by the eNB, each using a different PDCCH, wherein each of the DCI messages is intended to be received by one or more UEs. However, the UE does not know which PDCCH is used in a subframe and UE also does not know which of the PDCCHs contains DCI messages intended for said UE. Thus, UE has to perform many blind detection attempts per subframe in order to detect all DCI messages intended for said UE. Such blind detection is performed by decoding a DCI using a radio network temporary identifier (RNTI) of the UE. If there is a CRC error, the control data included in the respective DCI is not intended for the UE itself. If there is no CRC error while decoding, the control data included in the respective DCI is intended for the UE itself.

To facilitate and minimize the number of blind detection attempts of DCI messages at UE side, the PDCCHs are mapped into common and UE specific search spaces. In common search space (CSS), which is monitored by all UEs in a cell, DCI messages intended for a group of UEs are transmitted . The CSS is used to carry important initial information including paging information, system information and random access procedures. The UE-specific search space (USS) carries control information specific to a particular UE and is monitored by at least one UE in a cell .

A RAR message (Msg2) as mentioned above will be transmitted with physical downlink shared channel PDSCH, which is granted in a PDCCH addressed to a random access radio network temporary identifier (RA-RNTI) in CSS using the primary carrier, granted in a PDCCH addressed to a RA- RNTI in CSS using a primary/secondary carrier which is scheduling the secondary carrier on which the random access preamble is transmitted, or granted in a PDCCH addressed to a cell radio network temporary identifier (C-RNTI) using the primary carrier or a secondary carrier which is configured with the PDCCH.

The first two options require UE to do blind detection on CSS on secondary carrier, which might increase the peak number of the blind detection on secondary carrier although the maximum number of the blind detection on secondary carrier is not intended to increase.

In LTE Rel-10 a total number of blind detection attempts of a UE which is configured with carrier aggregation is defined. Such limit is chosen, since blind detecting imposes a substantial burden on the UE as at large bandwidths the control region containing the PDCCHs may be very large. This may exceed practical hardware limitations and lead to increased cost and/or reduced performance of the UE. The total blind detection number is defined as:

BD number = 44 + 32 x N_DL_SCC + 16 x N_ULM_CC

Wherein

- 44 times of blind detection means the maximum number of 32 blind detection attempts in USS and in 12 blind detection attempts in CSS on primary cell

- 32 x N_DL_SCC means that for each configured secondary carrier UE should perform 32 blind detection attempts in USS on secondary cell

- 16 x N_ULM_CC means 16 extra blind detection attempts for eNB configured UL multiple-input multiple-output (MIMO).

Observing this definition, the maximum number of blind detection attempts for each secondary carrier in a subframe is 32 + 16 = 48 in USS and 0 in CSS.

Due to the rising of multiple TA, the possibility of transmitting the RAR in CSS of a secondary carrier, the definition that 0 blind detection attempts for each secondary carrier might be allowed and since the increasing of the maximum of total blind detection attempts on a secondary carrier is not desired, the problem arises that currently UE is not required to do blind detection in CSS of a secondary carrier and thus no DCI message in CSS of a secondary carrier could be received . A RAR message transmitted in a PDCCH in CSS and necessary to compensate propagation delay between a UE and an eNB can thus not be detected . Thus, there is a need to utilize blind detection resources for USS and CSS flexibly and efficiently.

Summary

Various aspects of examples of the invention are set out in the claims.

According to a first aspect of the present invention, there is provided a device for communication, based on time slots, in a carrier aggregation mode aggregating a primary and at least one secondary carrier, comprising receiving means configured to receive a transmission taking place within a time slot using one of said at least one secondary carriers, said transmission being divided into a plurality of sections comprising predetermined first sections and predetermined second sections, said predetermined first and second sections containing control data, determination means configured to determine whether at least a part of said predetermined first and second sections is not to be checked, setting means configured to set, responsive to affirmative determination result, a first number indicating a number of first sections to be checked out of said predetermined first sections and a second number indicating a number of second sections to be checked out of said predetermined second sections, wherein a sum of said first and second numbers does not exceed a sum of a predetermined first number and a predetermined second number, and checking means configured to check, if said first number and said second number are set, for said set first number of predetermined first sections and for said set second number of predetermined second sections, whether said first and second sections contain control data intended for the device itself, and to check, if said first number and said second number are not set, for said predetermined first number of predetermined first sections and for said predetermined second number of predetermined second sections, whether said first and second sections contain control data intended for the device itself.

According to a second aspect of the present invention, there is provided a device for communication, based on time slots, in a carrier aggregation mode aggregating a primary and at least one secondary carrier, comprising transmission means configured to transmit configuration information indicative of a part of said predetermined second sections not to be checked, and configured to perform a transmission taking place within a time slot using one of said at least one secondary carriers, said transmission being divided into a plurality of sections comprising predetermined first sections and predetermined second sections, said predetermined first and second sections containing control data, and encoding means configured to encode said control data using an ID identifying an intended receiver or receiver group.

According to a third aspect of the present invention, there is provided a method for a device for communication, based on time slots, in a carrier aggregation mode aggregating a primary and at least one secondary carrier, comprising receiving a transmission taking place within a time slot using one of said at least one secondary carriers, said transmission being divided into a plurality of sections comprising predetermined first sections and predetermined second sections, said predetermined first and second sections containing control data, determining whether at least a part of said predetermined first and second sections is not to be checked, setting, responsive to affirmative determination result, a first number indicating a number of first sections to be checked out of said predetermined first sections and a second number indicating a number of second sections to be checked out of said predetermined second sections, wherein a sum of said first and second numbers does not exceed a sum of a predetermined first number and a predetermined second number, and checking, if said first number and said second number are set, for said set first number of predetermined first sections and for said set second number of predetermined second sections, whether said first and second sections contain control data intended for the device itself, and checking, if said first number and said second number are not set, for said predetermined first number of predetermined first sections and for said predetermined second number of predetermined second sections, whether said first and second sections contain control data intended for the device itself.

According to a fourth aspect of the present invention, there is provided a method for a device for communication, based on time slots, in a carrier aggregation mode aggregating a primary and at least one secondary carrier, comprising transmitting configuration information indicative of a part of said predetermined second sections not to be checked, transmitting a transmission taking place within a time slot using one of said at least one secondary carriers, said transmission being divided into a plurality of sections comprising predetermined first sections and predetermined second sections, said predetermined first and second sections containing control data, and encoding said control data using an ID identifying an intended receiver or receiver group.

According to a fifth aspect of the present invention, there is provided a computer program product for a device for communication, based on time slots, in a carrier aggregation mode aggregating a primary and at least one secondary carrier, comprising computer-executable components which, when executed on a computer, are configured to receive a transmission taking place within a time slot using one of said at least one secondary carriers, said transmission being divided into a plurality of sections comprising predetermined first sections and predetermined second sections, said predetermined first and second sections containing control data, to determine whether at least a part of said predetermined first and second sections is not to be checked, to set, responsive to affirmative determination result, a first number indicating a number of first sections to be checked out of said predetermined first sections and a second number indicating a number of second sections to be checked out of said predetermined second sections, wherein a sum of said first and second numbers does not exceed a sum of a predetermined first number and a predetermined second number, and to check, if said first number and said second number are set, for said set first number of predetermined first sections and for said set second number of predetermined second sections, whether said first and second sections contain control data intended for the device itself, and to check, if said first number and said second number are not set, for said predetermined first number of predetermined first sections and for said predetermined second number of predetermined second sections, whether said first and second sections contain control data intended for the device itself.

According to a sixth aspect of the present invention, there is provided a computer program product for a device for communication, based on time slots, in a carrier aggregation mode aggregating a primary and at least one secondary carrier, comprising computer-executable components which, when executed on a computer, are configured to transmit configuration information indicative of a part of said predetermined second sections not to be checked, to perform a transmission taking place within a time slot using one of said at least one secondary carriers, said transmission being divided into a plurality of sections comprising predetermined first sections and predetermined second sections, said predetermined first and second sections containing control data, and to encode said control data using an ID identifying an intended receiver or receiver group.

Respective advantageous further developments of the method and/or device are as set out in the corresponding dependent claims. The above computer program products may be embodied as a (volatile or non-volatile) computer-readable storage medium.

The methods, devices and computer program products described in this document, at least in exemplary embodiments, are able to utilize blind detection resources for USS and CSS flexibly and efficiently. In particular, a UE is able to share resources for blind detection attempts in USS and CSS among each other.

Brief descriptions of drawings For a more complete understanding of example embodiments of the present invention, reference is now made to the following descriptions taken in connection with the accompanying drawings in which :

FIGURE 1 illustrates a block diagram of an exemplary User Equipment, UE, according to one aspect of the invention;

FIGURE 2 illustrates a block diagram of an exemplary evolved Node B, eNodeB, according to one aspect of the invention;

FIGURE 3 illustrates exemplary method steps carried out by and implemented at the User Equipment side, UE side, according to one aspect of the invention;

FIGURE 4 illustrates exemplary method steps carried out by and implemented at the evolved Node B side, eNodeB side, according to one aspect of the invention; Description of exemplary embodiments

Exemplary aspects of the invention will be described herein below.

It is to be noted that the following exemplary description refers to an environment of the LTE system (long term evolution) in which carrier aggregation is deployed. However, it is to be understood that this serves for explanatory purposes only. Other system differing from the LTE system can be adopted as long as they deploy carrier aggregation. In such carrier aggregation, one carrier is a primary carrier and at least one carrier aggregated with a primary component carrier is referred to as secondary carrier. Thus, in a communication configured in carrier aggregation mode, a primary and at least one secondary carrier are present. The communication is performed based on time slots and in channels. Those channels are divided in payload channels and control channels. Examples for payload channels are the physical downlink shared channel PDSCH for transmission of payload data in downlink direction and physical uplink shared channel PUSCH for transmission of payload data in uplink direction. Examples for control channels are the physical downlink control channel PDCCH for transmission of control information in downlink direction and physical uplink control channel PUCCH for transmission of control information in uplink transmission.

Now, it is more specifically referred to the drawings and exemplary embodiments illustrated therein.

Figure 1 illustrates a block diagram of an exemplary User Equipment, UE, according to one aspect of the invention. Said UE (1) comprises communication means (2) which configured for communication in a carrier aggregation mode. In order to receive at least control data, receiving means (3) is arranged in said UE and is configured to receive a transmission which may be divided into a plurality of sections comprising predetermined first sections and predetermined second sections, said predetermined first and second sections containing control data. The UE further comprises determination means (4) for determining whether at least a part of said predetermined first and second sections is not to be checked . Furthermore, setting means (5) are arranged in the UE. Said setting means sets, based on the determination result, a first number indicating a number of predetermined first sections to be checked and a second number indicating a number of predetermined second sections to be checked, wherein a sum of said first and second numbers does not exceed a sum of a predetermined first number and a predetermined second number. A checking means (4) checks, for said set first number of predetermined first sections and for said set second number of predetermined second sections, whether said sections contain control data intended for the device itself, if said first number and said second number are set, and to check, for said predetermined first number of predetermined first sections and for said predetermined second number of predetermined second sections, whether said sections contain control data intended for the device itself, if said first number and said second number are not set.

Figure 2 illustrates a block diagram of an exemplary evolved Node B, eNB, according to one aspect of the invention. Said eNB (11) comprises a communication means (12) for communication in a carrier aggregation mode. A transmission means (13) is arranged in said eNB and is configured to transmit configuration information indicative of a part of said second sections not to be checked, and configured to perform a transmission which is divided into a plurality of sections comprising predetermined first sections and predetermined second sections, wherein said predetermined first and second sections contains control data. Furthermore, encoding means (14) are included in the eNB. Said encoding means is configured to encode said control data using an ID identifying an intended receiver or receiver group.

Figure 3 illustrates exemplary method steps carried out by and implemented at the User Equipment side, UE side, according to one aspect of the invention. The process starts in an initial step SI at the UE. In the following step S2 a first number is set to a predetermined first number and a second number is set to a predetermined second number. Said numbers denote how many blind detection attempts are allowed to be performed on predetermined first and second sections respectively of a transmission within a subframe. Said predetermined numbers may be predetermined by a communication standard like LTE. Said set numbers are modified values in order to share resources for blind detection attempts in the predetermined first and second sections. Each of said predetermined first sections may be a PDCCH in a common search space of a transmission according to a communication standard like LTE, wherein each of the predetermined second sections may be a PDCCH in a UE specific search space of a transmission according to a communication standard like LTE.

In the following step S3, the UE receives configuration information which indicate one ore more control data that is or are not intended for the UE itself and therefore not to be checked. The control data may by embedded in a downlink control information (DCI) message. The indication of said DCI message may be one of a length, e.g . an aggregation level of said DCI message, a location in the transmission, e.g. a starting point of said DCI message or a DCI format of said DCI message. After that, in step S4 the UE receives a transmission within a subframe, that contains control data, which may be embedded in DCI messages.

In step S5, the UE determines whether a part of second sections of said received transmission are not to be checked . Said part of second sections may be determined by use of the received control information, i.e. the DCI messages that are not to be checked.

If it is determined that a part of second sections of said received transmission is not to be checked (Yes in step S5), the process advances to step S6.

In step S6, the first number is set to a sum of the first number and the amount of second sections that are not to be checked, i.e. the amount of DCI messages that are determined as not to be checked . After that, in step S7, the second number is set by subtracting the amount of second sections that are not to be checked, i.e. the amount of DCI messages that are determined as not to be checked from the second number.

In steps S6 and S7 thus the unused blind detection resources are moved from blind detection in said second sections to blind detection in said first sections, i.e. from blind detections in USS to blind detections in CSS. The process advances then to step S8.

If it is determined in step S5 that no part of predetermined second sections of said received transmission is not to be checked (No in step S5), the process advances to step S8.

In step S8 the predetermined first sections, i.e. the DCI messages in the CSS, are checked whether they contain control data intended for the UE wherein the maximum of checked predetermined first sections is limited to the set first number. Furthermore, the predetermined second sections, i.e. the DCI messages in the USS, are checked whether they contain control data intended for the UE wherein the maximum of checked predetermined second sections is limited to the set second number.

The checking of step S8 is performed by decoding said DCI messages using the UEs ID. If no error occurs on decoding, the message is intended for the UE. After that, the procedure advances to step S9, which denotes the end step.

As a further example, the determination may also be based on a state of the UE itself. The UE may be situated in a not synchronized state with respect to the eNB. In this state, the UE can not be an intended receiver of downlink or uplink scheduling information carried in a PDCCH of a USS. Thus, the UE does not have to use blind detection resources for detection of DCI messages in the USS. Instead, UE may use all blind detection resources to detect DCI messages in the CSS, which may be a RAR advancing a synchronizing of the UE with the eNB.

A further state may be a configured transmission mode, which requires extra blind detection attempts, like a MIMO transmission mode in the communication standard LTE. If such transmission mode is configured, but a usage of the corresponding features can be suspended, the UE can suspend receiving of MIMO transmission mode related DCI messages in the USS. Instead, UE may use those extra blind detection resources to detect DCI messages in the CSS.

In particular, the uplink transmission mode for each component carrier may be independent from each other. When UE is configured with UL MIMO transmission mode on a secondary carrier, UE has to monitor both DCI format 0 and DCI format 4 for UL grant information. In this case, one possibility is to define the search space so that

- UE does not have to monitor the DCI format 4 (corresponding to UL MIMO) in USS of the secondary carrier, and - UE monitors PDCCH encoded with RA-RNTI in CSS of the secondary carrier

The number of blind detections corresponding to CSS of the secondary carrier can be equal or less than that of DCI format 4, dropped from USS of the secondary carrier and shared with the CSS.

As the time period needed for blind detecting RAR messages on CSS of the secondary carrier is not long, a random access procedure on a secondary carrier may not be a frequent event, and communication not using MIMO features is not affected, suspending of the MIMO features does not induce an unduly performance loss.

As a further example, the determination may also be based on a further configuration. If a transmission mode, which requires extra blind detection attempts, like a MIMO transmission mode in the communication standard LTE is not configured for the UE, the number of possible blind detection attempts for a secondary carrier in a subframe is limited to 32, since the extra blind detection attempts (16) are not present. This number of allowed blind detection attempts is divided into 16 attempts for DCI message format 0/lA, which may carry downlink assignment information or uplink grant information, and 16 attempts for other DCI formats which is transmission mode dependent. If a UE is configured to reduce the number of attempts for DCI message format 0/lA in USS, it is possible to use the freed blind detection attempts in CSS of the secondary carrier. Such further configuration may be performed by the eNB via radio resource control (RRC) signaling, but is not limited to that example.

In this way, UE may try a configured decreased number of blind detections corresponding to DCI format 0/lA in the USS on the secondary carrier, and can then, for example, monitor a PDCCH scrambled with RA-RNTI in CSS of the secondary carrier in order to receive an expected RAR message.

Although less DCI messages using format 1A can be used, a scheduling flexibility of PDSCH is hardly affected, since another transmission dependent transmission mode can still be used for DL grant, and DCI format 1A is used mainly for backup purpose. Furthermore, the time period needed for blind detecting RAR messages on CSS of the secondary carrier is not long and a random access procedure on a secondary carrier may not be a frequent event.

Furthermore, the invention is not limited to provide blind detection resources from the USS to the CSS, but also from the CSS to the USS. For example, if UE doesn't need to monitor the system information radio network temporary identifier (SI-RNTI), since there is no expected system information, doesn't need to monitor RAR since it does not start a RACH preamble procedure, doesn't need to monitor transmitter power control radio network temporary identifier (TPC-RNTI) if it is configured to do so, UE could share the blind detection resources from CSS to USS to enable more blind detection attempts in USS.

Figure 4 illustrates exemplary method steps carried out by and implemented at the evolved Node B side, eNodeB side, according to one aspect of the invention. The process starts in an initial step Sl l at the eNB. In the following step S12 configuration information is transmitted . Such configuration information indicates one ore more control data that is or are not to be checked . The control data may by embedded in a downlink control information (DCI) message. The indication of said DCI message may be one of a length, e.g. an aggregation level of said DCI message, a location in the transmission, e.g. a starting point of said DCI message or a DCI format of said DCI message. The configuration information may further include information concerning the time when sharing blind detection resources will be allowed . After that, in step S13, control data to be transmitted, i.e. a DCI message is encoded using an ID which identifies the intended receiver(s).

In the following step S14, transmission of the encoded control data is performed using sections within the predetermined first and second sections, i.e. within the CSS and the USS of a transmission within a subframe. Of course, a DCI message for a UE is not transmitted with the features that are communicated to the receiver as being not necessary to be checked.

Generally, the invention is implemented in an environment such as LTE system adopting carrier aggregation. Exemplary embodiments of the invention are represented by methods and/or correspondingly configured devices such as eNodeBs and/or UEs. More specifically, the invention generally relates to modem modules of such devices. Other systems can benefit also from the principles presented herein as long as they have identical or similar properties like the carrier aggregation under LTE.

Embodiments of the present invention may be implemented in software, hardware, application logic or a combination of software, hardware and application logic. The software, application logic and/or hardware generally, but not exclusively, may reside on the devices' modem module. In an example embodiment, the application logic, software or an instruction set is maintained on any one of various conventional computer-readable media. In the context of this document, a "computer-readable medium" may be any media or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer or smart phone, or user equipment.

The present invention relates in particular but without limitation to mobile communications, for example to environments under LTE, WCDMA, WIMAX and WLAN and can advantageously be implemented in user equipments or smart phones, or personal computers connectable to such networks. That is, it can be implemented as/in chipsets to connected devices, and/or modems thereof.

If desired, the different functions discussed herein may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the above-described functions may be optional or may be combined. Although various aspects of the invention are set out in the independent claims, other aspects of the invention comprise other combinations of features from the described embodiments and/or the dependent claims with the features of the independent claims, and not solely the combinations explicitly set out in the claims.

It is also noted herein that while the above describes example embodiments of the invention, these descriptions should not be viewed in a limiting sense. Rather, there are several variations and modifications which may be made without departing from the scope of the present invention as defined in the appended claims.

The present invention proposes methods for devices, devices and computer program products for devices in relation to a communication module configured for communication, based on time slots, in a carrier aggregation mode aggregating a primary and at least one secondary carrier. Receiving a transmission divided into a plurality of sections comprising predetermined first sections and predetermined second sections, said predetermined first and second sections containing control data, is performed . It is determined whether at least a part of said predetermined first and second sections is not to be checked . Based on the determination result, a first and second number are set. It is checked for the first number of predetermined first sections and for the second number of predetermined second sections, whether said sections contain control data intended for the device itself.

List of acronyms, abbreviations and definitions

C-RNTI Cell Radio Network Temporary Identifier

CA Carrier Aggregation

CC Component Carrier

CSS Common Search Space

DCI Downlink Control Information

eNB eNodeB, evolved Node B

LTE Long Term Evolution

PDCCH Physical Downlink Control CHannel PDSCH Physical Downlink Shared CHannel

PRACH Physical Random Access CHannel

PUCCH Physical Uplink Control CHannel

PUSCH Physical Uplink Shared Channel

RA-RNTI Random Access Radio Network Temporary Identifier

RACH Random Access CHannel

RAR Random Access Response

RNTI Radio Network Temporary Identifier

RRH Radio Remote Head

SI-RNTI System Information Radio Network Temporary Identifier

TPC-RNTI Transmitter Power Control Radio Network Temporary Identifier

TA Timing Advance

UE User Equipment

USS UE-specific Search Space

Claims

WHAT IS CLAIMED IS:

1. A device for communication, based on time slots, in a carrier aggregation mode aggregating a primary and at least one secondary carrier, comprising : receiving means configured to receive a transmission taking place within a time slot using one of said at least one secondary carriers, said transmission being divided into a plurality of sections comprising predetermined first sections and predetermined second sections, said predetermined first and second sections containing control data,

determination means configured to determine whether at least a part of said predetermined first and second sections is not to be checked,

setting means configured to set, responsive to affirmative determination result, a first number indicating a number of first sections to be checked out of said predetermined first sections and a second number indicating a number of second sections to be checked out of said predetermined second sections, wherein a sum of said first and second numbers does not exceed a sum of a predetermined first number and a predetermined second number, and

checking means configured to check, if said first number and said second number are set, for said set first number of predetermined first sections and for said set second number of predetermined second sections, whether said first and second sections contain control data intended for the device itself, and to check, if said first number and said second number are not set, for said predetermined first number of predetermined first sections and for said predetermined second number of predetermined second sections, whether said first and second sections contain control data intended for the device itself.

2. The device according to claim 1, wherein

said determination means is configured to perform determination based on whether no control data intended for the device itself is expected to be contained in said predetermined second sections of said received transmission, and said setting means is configured to, responsive to affirmative determination result, set said first number by adding said predetermined first number and said predetermined second number and to set said second number to zero.

3. The device according to claim 2, wherein

said setting means is configured to, when said device is in a not synchronized mode, set said first number by adding said predetermined first number and said predetermined second number and to set said second number to zero.

4. The device according to claim 1, wherein

said determination means is configured to perform determination based on whether no control data intended for the device itself is expected to be contained in a part of said predetermined second sections of said received transmission, and

said setting means is configured to, responsive to affirmative determination result, set said first number by adding said predetermined first number and an amount corresponding to an amount of sections included in said part of said predetermined second sections and to set said second number by subtracting said amount corresponding to said amount of sections included in said part of said predetermined second sections from said predetermined first number.

5. The device according to claim 4, wherein

said setting means is configured to set, in a first transmission mode, in which no control data intended for the device itself is contained in a part of said predetermined second sections of said received transmission, said first number by adding said predetermined first number and an amount corresponding to an amount of sections included in said part of said predetermined second sections in which no control data intended for the device itself is contained in said first transmission mode, and to set said second number by subtracting said amount corresponding to said amount of sections included in said part of said predetermined second sections in which no control data intended for the device itself is contained in said first transmission mode from said predetermined first number.

6. The device according to claim 1, wherein

said receiving means is configured to receive configuration information indicative of a part of said predetermined second sections not to be checked,

said determination means is configured to perform determination based on said received configuration information, and

7. The device according to claim 6, wherein

each of said predetermined first and second sections is identified by at least one of a length, a location in the transmission, and a format of control data contained, and

said configuration information indicates said second sections included in said part of said predetermined second sections not to be checked by containing at least one of said length, said location in the transmission, and said format of control data contained of said second sections not to be checked.

8. The device according to claim 1, wherein

said determination means is configured to perform determination based on whether no control data is expected to be contained in said predetermined first sections of said received transmission, and said setting means is configured to, responsive to affirmative determination result, set said second number by adding said predetermined first number and said predetermined second number and to set said first number to zero.

9. The device according to any of claims 1 to 8, wherein

said device is identified by at least one ID,

said predetermined first and second sections contain control data intended for the device itself, if said contained control data is encoded using one of said at least one IDs identifying said device, and

said checking means is configured to check by decoding said contained control data with each of said at least one IDs.

10. The device according to any of claims 1 to 9, wherein

each of said predetermined first sections is a physical downlink control channel PDCCH in a common search space CSS,

each of said predetermined second sections is a physical downlink control channel PDCCH in a UE specific search space USS, and

said control data is a downlink control information DCI.

11. A device for communication, based on time slots, in a carrier aggregation mode aggregating a primary and at least one secondary carrier, comprising :

transmission means configured to transmit configuration information indicative of a part of said predetermined second sections not to be checked, and configured to perform a transmission taking place within a time slot using one of said at least one secondary carriers, said transmission being divided into a plurality of sections comprising predetermined first sections and predetermined second sections, said predetermined first and second sections containing control data, and

encoding means configured to encode said control data using an ID identifying an intended receiver or receiver group.

12. The device according to claim 11, wherein

13. The device according to any of claims 11 and 12, wherein

said control data is a downlink control information DCI.

14. A method for a device for communication, based on time slots, in a carrier aggregation mode aggregating a primary and at least one secondary carrier, comprising :

receiving a transmission taking place within a time slot using one of said at least one secondary carriers, said transmission being divided into a plurality of sections comprising predetermined first sections and predetermined second sections, said predetermined first and second sections containing control data,

determining whether at least a part of said predetermined first and second sections is not to be checked,

setting, responsive to affirmative determination result, a first number indicating a number of first sections to be checked out of said predetermined first sections and a second number indicating a number of second sections to be checked out of said predetermined second sections, wherein a sum of said first and second numbers does not exceed a sum of a predetermined first number and a predetermined second number, and checking, if said first number and said second number are set, for said set first number of predetermined first sections and for said set second number of predetermined second sections, whether said first and second sections contain control data intended for the device itself, and checking, if said first number and said second number are not set, for said predetermined first number of predetermined first sections and for said predetermined second number of predetermined second sections, whether said first and second sections contain control data intended for the device itself.

15. The method according to claim 14, wherein

said determining is performed based on whether no control data intended for the device itself is expected to be contained in said predetermined second sections of said received transmission, and

said setting is performed by, responsive to affirmative determination result, setting said first number by adding said predetermined first number and said predetermined second number and setting said second number to zero.

16. The method according to claim 15, wherein

said setting is performed by, when said device is in a not synchronized mode, setting said first number by adding said predetermined first number and said predetermined second number and setting said second number to zero.

17. The method according to claim 14, wherein

said determining is performed based on whether no control data intended for the device itself is expected to be contained in a part of said predetermined second sections of said received transmission, and

said setting is performed by, responsive to affirmative determination result, setting said first number by adding said predetermined first number and an amount corresponding to an amount of sections included in said part of said predetermined second sections and setting said second number by subtracting said amount corresponding to said amount of sections included in said part of said predetermined second sections from said predetermined first number.

18. The method according to claim 17, wherein

said setting is performed by setting, in a first transmission mode, in which no control data intended for the device itself is contained in a part of said predetermined second sections of said received transmission, said first number by adding said predetermined first number and an amount corresponding to an amount of sections included in said part of said predetermined second sections in which no control data intended for the device itself is contained in said first transmission mode, and setting said second number by subtracting said amount corresponding to said amount of sections included in said part of said predetermined second sections in which no control data intended for the device itself is contained in said first transmission mode from said predetermined first number.

19. The method according to claim 14, further comprising

receiving configuration information indicative of a part of said predetermined second sections not to be checked, wherein

said determining is performed based on said received configuration information, and

20. The method according to claim 19, wherein each of said predetermined first and second sections is identified by at least one of a length, a location in the transmission, and a format of control data contained, and

21. The method according to claim 14, wherein

said determining is performed based on whether no control data is expected to be contained in said predetermined first sections of said received transmission, and

said setting is performed by, responsive to affirmative determination result, setting said second number by adding said predetermined first number and said predetermined second number and setting said first number to zero.

22. The method according to any of claims 14 to 21, wherein

said device is identified by at least one ID,

said checking is performed by decoding said contained control data with each of said at least one IDs.

23. The method according to any of claims 14 to 22, wherein

said control data is a downlink control information DCI.

24. A Method for a device for communication, based on time slots, in a carrier aggregation mode aggregating a primary and at least one secondary carrier, comprising :

transmitting configuration information indicative of a part of said predetermined second sections not to be checked,

transmitting a transmission taking place within a time slot using one of said at least one secondary carriers, said transmission being divided into a plurality of sections comprising predetermined first sections and predetermined second sections, said predetermined first and second sections containing control data, and

encoding said control data using an ID identifying an intended receiver or receiver group.

25. The method according to claim 24, wherein

26. The method according to any of claims 24 and 25, wherein

said control data is a downlink control information DCI.

27. A computer program product for a device for communication, based on time slots, in a carrier aggregation mode aggregating a primary and at least one secondary carrier, comprising computer-executable components which, when executed on a computer, are configured

to receive a transmission taking place within a time slot using one of said at least one secondary carriers, said transmission being divided into a plurality of sections comprising predetermined first sections and predetermined second sections, said predetermined first and second sections containing control data,

to determine whether at least a part of said predetermined first and second sections is not to be checked,

to set, responsive to affirmative determination result, a first number indicating a number of first sections to be checked out of said predetermined first sections and a second number indicating a number of second sections to be checked out of said predetermined second sections, wherein a sum of said first and second numbers does not exceed a sum of a predetermined first number and a predetermined second number, and

to check, if said first number and said second number are set, for said set first number of predetermined first sections and for said set second number of predetermined second sections, whether said first and second sections contain control data intended for the device itself, and to check, if said first number and said second number are not set, for said predetermined first number of predetermined first sections and for said predetermined second number of predetermined second sections, whether said first and second sections contain control data intended for the device itself.

28. A computer program product for a device for communication, based on time slots, in a carrier aggregation mode aggregating a primary and at least one secondary carrier, comprising computer-executable components which, when executed on a computer, are configured

to transmit configuration information indicative of a part of said predetermined second sections not to be checked,

to perform a transmission taking place within a time slot using one of said at least one secondary carriers, said transmission being divided into a plurality of sections comprising predetermined first sections and predetermined second sections, said predetermined first and second sections containing control data, and

to encode said control data using an ID identifying an intended receiver or receiver group.