CN102843748B

CN102843748B - A kind of method and device of determination search space

Info

Publication number: CN102843748B
Application number: CN201110169149.9A
Authority: CN
Inventors: 袁明; 毕峰; 梁枫; 杨瑾; 吴栓栓
Original assignee: ZTE Corp
Current assignee: Rudong County Shengtai New Rural Development And Construction Co Ltd
Priority date: 2011-06-22
Filing date: 2011-06-22
Publication date: 2017-09-12
Anticipated expiration: 2031-06-22
Also published as: WO2012174913A1; CN102843748A

Abstract

The invention discloses a kind of method and device of determination search space, including according to the number and its corresponding original position of degree of polymerization acquisition candidate control channel, determine the search space corresponding to different polymerization degree；The blind Detecting down control channel in the search space corresponding to different polymerization degree；Wherein, as L or Λ=16, the number of the candidate control channel corresponding to it is 1 or 2, and as L or Λ=32, the number of the candidate control channel corresponding to it is 1；And, the original position of different L and the search space corresponding to Λ is fixed；Or, notified by high-level signaling is semi-static.The inventive method is solved under high-speed mobile scene, the problem of how mobile relay searches for the down control channel of oneself.It is perfectly suitable for mobile relay (or terminal of more highest version), significantly simplify in band/with detection complexity of the outer via node to its down control channel, via node is perfectly suitable for, overhead is saved, the efficiency of transmission of system is improved.

Description

Method and device for determining search space

Technical Field

The present invention relates to a method and an apparatus for determining a search space of a downlink control channel of a mobile relay.

Background

Long Term Evolution (LTE), LTE-Advanced (LTE-a) and International mobile telecommunications-Advanced (IMT-Advanced) systems, all based on Orthogonal Frequency Division Multiplexing (OFDM) technology; the OFDM system is a time-frequency two-dimensional data format, wherein 1 subframe (subframe) is composed of 2 slots (slots), and each slot is composed of 6 OFDM symbols when an extended CP (extended CP) is composed of 7 OFDM symbols in a Normal Cyclic Prefix (Normal CP). Wherein, a Physical Downlink Control Channel (PDCCH) is located on the first 1 or 2 or 3 or 4 OFDM symbols of the 1 st slot of each subframe.

In the LTE system, the design of the PDCCH consists of several different components, and for convenience of description, several terms are explained below:

resource Element (RE): the minimum time-frequency resource block occupies 1 subcarrier on 1 OFDM symbol;

resource Element Group (REG, Resource Element Group): the 1 REG may consist of 4 or 6 REs, depending on the reference symbol position on each OFDM symbol;

control information Element (CCE): consists of 36 REs and 9 REGs, and the information contained in the CCE is as follows: downlink scheduling grant Information (DL grant) and uplink scheduling grant Information (UL grant) of the user, and Information related to System Information (SI, System Information), Random Access (RA), Paging (Paging);

physical Resource Block (PRB): 1 continuous time slot is arranged on a time domain, and 12 continuous sub-carriers are arranged on a frequency domain;

physical resource block pair (PRB pair): 1 continuous subframe on the time domain and 12 continuous subcarriers on the frequency domain;

virtual Resource Block (VRB): the logical concept, size, is the same as PRB. According to different mapping modes from VRB to PRB, two types can be used, namely continuous VRB and discrete VRB. Similarly, the sizes of the VRBpair and the PRB pair are also the same;

polymerization degree (Aggregation level) L: a combination form of CCEs, wherein a PDCCH consists of L CCEs, and L is formed by {1,2,4,8}, namely the PDCCH only consists of a combination of 1 CCE (represented by 1-CCE), a combination of 2 CCEs (represented by 2-CCE), a combination of 4 CCEs (represented by 4-CCE) and a combination of 8 CCEs (represented by 8-CCE), and the 4 different combinations respectively correspond to 4 different coding rates, namely the coding rate of 1-CCE is 2/3, the coding rate of 2-CCE is 1/3, the coding rate of 4-CCE is 1/6 and the coding rate of 8-CCE is 1/12;

search Space (SS, Search Space): the UE monitors a search space and performs blind detection in the search space so as to detect a downlink control channel related to the UE. There are two types of search spaces: one is a common Search Space (UE-common Search Space), i.e. a Search Space to be monitored by all UEs, and carries common information related to System Information (SI), Random Access (RA) response and Paging (Paging); the other is a Search Space (UE-specific Search Space) dedicated to the UE, wherein the carried information is uplink and downlink scheduling authorization information of the UE itself;

control channel candidate (PDCCH candidate): different CCE aggregation levels L all correspond to one PDCCH candidate number, namely the maximum number of blind detections. For example, in the UE's dedicated search space: the number of PDCCH candidates of 1-CCE (L ═ 1) is 6, that is, the number of times of blind detection performed on a 1-CCE group does not exceed 6; the number of PDCCH candidates of 2-CCE (L ═ 2) is 6, that is, the number of times of blind detection performed on a group of 2 CCEs does not exceed 6; the number of PDCCH candidates of 4-CCE (L ═ 4) is 2, that is, the number of times of blind detection performed on a 4-CCE group is not more than 2; the number of PDCCH candidates for 8-CCE (L ═ 8) is 2, that is, the number of times of blind detection is not more than 2 per 8 CCE group. In the common search space of the UE: 4 PDCCH candidates of 4-CCE are total, namely the blind detection times according to a group of 4 CCE are not more than 4; the PDCCH candidates of the 8-CCE are 2 in total, namely the blind detection times according to a group of 8 CCEs are not more than 2;

starting position of search space: the starting location of the common search space is always CCE 0; the starting position of the UE-specific search space is calculated according to parameters such as UE-ID, total number of CCEs, L value, subframe number, and number of candidate control channels.

The process of blind detection of PDCCH by UE in LTE system includes:

at an Evolved node b (where eNB is also called an Evolved node b, i.e. an Evolved Universal Terrestrial Radio access network node (E-UTRAN NodeB), where E-UTRAN is an abbreviation of Evolved Universal Radio access network), the method includes:

respectively carrying out channel coding on control information carried by the PDCCH of each UE;

the coded control information carried by the PDCCHs of all the UE is concatenated and scrambled by a sequence special for a cell;

performing Quadrature Phase Shift Keying (QPSK) modulation, obtaining a series of CCEs corresponding to control information carried by all PDCCHs at this time, and numbering the CCEs from 0; it is assumed that the downlink control channel at this time is composed of 32 CCEs in total, that is, the numbers of them are CCE0, CCE1, …, and CCE 31;

interleaving the series of CCEs by taking the REG as a unit, and mapping the series of CCEs to the RE according to a specific mapping rule;

after Inverse Fast Fourier Transform (IFFT), the signal is transmitted.

At the UE side, the method includes:

the receiving end carries out Fast Fourier Transform (FFT), and a series of CCEs with the same number as the eNB end are obtained after de-interleaving;

the UE starts to perform blind detection from the combination of 1-CCE, firstly calculates the initial position of the 1-CCE according to the parameters of the UE ID, the subframe number and the like, namely, the blind detection is performed from the initial CCE, and then the specific search space is determined according to the number of PDCCH candidates. For example, if the starting position of 1-CCE is CCE5, the search space of the UE is { CCE5, CCE6, CCE7, CCE8, CCE9, CCE10 }. That is, the UE performs blind detection on [ CCE5, CCE6, CCE7, CCE8, CCE9, CCE10 ] respectively;

if the UE does not detect the PDCCH matched with the UE ID of the UE when blind detection is carried out according to the combination of 1-CCE, then blind detection is carried out from the combination of 2-CCE. Firstly, the initial position of the 2-CCE still needs to be calculated according to parameters such as the UE ID and the subframe number of the user equipment, and then the search space is determined according to the number of PDCCH candidates. For example, if the starting position of 2-CCE is CCE10, the search space of the UE is { [ CCE10 CCE11 ], [ CCE12 CCE13 ], …, [ CCE20 CCE21 ] }. That is, the UE blindly detects [ CCE10 CCE11 ], [ CCE12 CCE13 ], …, and [ CCE20 CCE21 ], respectively. And so on;

if the UE does not monitor the PDCCH matched with the UE ID of the UE in the whole blind detection process, the UE does not issue a downlink control signaling belonging to the UE at the moment, and the UE discards the PDCCH; if the PDCCH matched with the UE ID of the UE is monitored, the UE receives or sends corresponding service data according to the indication of the downlink control signaling.

This presents new challenges to wireless communication technologies as future wireless communication or cellular systems require increased coverage to support higher rate transmissions. At the same time, the cost of system construction and maintenance is more problematic. As transmission rates and communication distances increase, battery power consumption becomes more problematic, and future wireless communications will use higher frequencies, resulting in more severe path loss attenuation. In order to increase the coverage of high data rate, group mobility, temporary network deployment, improve the throughput at the cell edge, and provide services for users within the coverage hole of the cellular system, a Relay (Relay) technology is introduced into the wireless communication system, and therefore, the Relay technology is regarded as a key technology of 4G.

In a mobile communication system in which a Relay Node (RN) is introduced, a Link between a base station (eNB) and the RN is referred to as a Relay Link (also referred to as a Un Link), a Link between the RN and a User Equipment (UE) under its coverage is referred to as an Access Link (also referred to as a Uu Link), and a Link between the eNB and the UE under its coverage is referred to as a Direct Link (Direct Link). For eNB, RN is equivalent to one UE; for the UE, the RN is equivalent to the eNB.

Relay nodes can be divided into two types, namely, in-band relay nodes and out-of-band relay nodes.

In the case of an in-band RN, the same frequency band is used for both the Un Link and the Uu Link, which both use the frequency f as shown in FIG. 1₁. In order to avoid the interference of the RN in transmitting and receiving, the RN cannot simultaneously perform the operations of transmitting and receiving on the same frequency resource. When the RN transmits downlink control information to its subordinate UE, it cannot receive the downlink control information from the eNB. Therefore, in Downlink transmission, the RN first sends Downlink Control information to its subordinate UE on the first 1 or 2 OFDM symbols, then performs a handover from transmission to reception within a time range (e.g. at an interval gap shown in fig. 2), and after the handover is completed, receives data from the eNB on the following OFDM symbols, where the data includes a Relay-specific Downlink Control Channel (R-PDCCH) and a Physical Downlink Shared Channel (PDSCH), as shown in fig. 2, that is, the R-PDCCH sent by the eNB to the RN is carried on a Physical resource block or a Physical resource block pair.

For an out-of-band relay node (out-band RN), the Un Link and the Uu Link occupy two completely different frequency bands, as shown in FIG. 3, the Un Link uses a frequency f₁Uulink frequency of use f₂. Thus, the out-of-band RN may be at f₁While transmitting (receiving) on f₂And (3) upper receiving (transmitting), wherein the transmitting and the receiving do not generate interference. Therefore, the outband relay node can receive the information transmitted by the base station on any OFDM symbol of each subframe.

The R-PDCCH may or may not be interleaved during transmission. Wherein,

the interleaved R-PDCCH (with cross-interleaving) means that dlgrants of all RNs in one subframe are interleaved with each other and then are carried on available resources of the 1 st time slot; and interleaving the UL grants of all RNs in one subframe and then carrying the UL grants on the available resources of the 2 nd time slot, namely R-PDCCHs of the RNs are carried in 1 RB pair.

The non-interleaved R-PDCCH (non-interleaved) means that the eNB semi-statically configures a set of dedicated VRB pairs for different RNs to carry the R-PDCCH by using higher layer signaling, where a DL grant of an RN is transmitted on an available resource of a 1 st time slot and a UL grant of an RN is transmitted on an available resource of a 2 nd time slot, that is, only the R-PDCCH of the same RN can be carried in 1 VRB pair, and cannot be shared by multiple RNs.

The method for determining the search space of the R-PDCCH in the LTE-A system basically adopts the method for determining the search space in the blind detection process of the UE. The main differences are as follows:

the RN has no common search space, only a dedicated search space.

Search space of non-interleaved R-PDCCH: the R-PDCCH consists of Λ VRB pair, wherein Λ is ∈ {1,2,4,8}, the number of R-PDCCH candidates corresponding to each R-PDCCH is {6,6,2,2}, and the initial positions of the search spaces corresponding to different Λ are all VRB 0.

In 3GPP discussions, Mobile Relay (MR) will become a hot spot problem. Because high-speed movement generates large Doppler frequency offset, an OFDM system is very easily influenced by the frequency offset, namely, a small frequency offset destroys the orthogonality among subcarriers, so that a user is difficult to correctly receive data. In addition, the increase of the doppler frequency offset also shortens the coherence time of the channel, i.e. causes rapid changes of the wireless channel, which also seriously affects the correct reception of data. In order to solve the problem of correct reception of the downlink control channel, a new downlink control channel format is likely to be introduced, and the change of the aggregation level L value of the R-PDCCH can cause the change of the initial position and the size of the R-PDCCH search space and the number of blind tests of the mobile relay.

Thus, the existing method for determining the search space through the UE blind detection process is not suitable for the mobile relay.

Disclosure of Invention

In view of the above, the main objective of the present invention is to provide a method and an apparatus for determining a search space, which can determine a search space of a downlink control channel of a mobile relay in a high-speed moving scene.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a method of determining a search space, comprising,

obtaining the number of candidate control channels and corresponding initial positions thereof according to the polymerization degree, and determining search spaces corresponding to different polymerization degrees;

blind detecting a downlink control channel in search spaces corresponding to different polymerization degrees;

when the downlink control channel of the mobile relay consists of L ═ 16 CCEs, the number of the corresponding candidate control channels is 1 or 2; when the downlink control channel of the mobile relay consists of L-32 CCEs, the number of the corresponding candidate control channels is 1; when the downlink control channel of the mobile relay is composed of the VRB pair of 16 physical resource blocks, the number of the corresponding candidate control channels is 1 or 2; when the downlink control channel of the mobile relay consists of Λ ═ 32 VRB pairs, the number of the corresponding candidate control channels is 1;

the initial positions of the search spaces corresponding to different L and Lambda are fixed; or semi-statically notified by higher layer signaling.

The values of L and Lambda are respectively as follows: 1 or 2 or 4 or 8 or 16 or 32.

For the in-band non-interleaving condition, the starting positions of the search spaces corresponding to the different lambada are the same; or, differently; or, some are the same and the remainder are different;

the starting position is indicated by a VRB index number.

For the downlink control channel of the outband mobile relay, the downlink control channel is composed of L CCEs, and the starting positions of the search spaces corresponding to different L are as follows:

the base station fixes the initial position of the search space of each outband mobile relay under the base station as a specific CCE index number; or the initial CCE index number is semi-static and variable, and the initial CCE index number and the total number of the CCEs are informed by high-level signaling;

and the out-of-band mobile relays perform blind detection in sequence from the respective initial CCE index numbers, and the maximum CCE index number in the search space does not exceed the total number of the CCEs.

the base station respectively allocates a group of fixed CCEs for each out-of-band mobile relay under the base station to bear a downlink control channel of the base station;

blind detection is carried out on each out-of-band mobile relay in each search space range, and the initial positions of the search spaces corresponding to different L are all the 1 st CCE in each search space range;

the set of CCEs is fixed or semi-static and is signaled by higher layer signaling.

the base station sets a group of CCE index numbers occupied by downlink control channels of the mobile relay with the out-of-band as fixed values or semi-statically variable, and notifies the fixed values by high-level signaling;

the search space of each outband mobile relay is the set of CCEs pre-allocated.

When a downlink control channel of the out-of-band mobile relay is composed of the Λ VRB pair, the initial positions of the search spaces corresponding to different Λ are the same; or, differently; or, some are the same and the remainder are different;

the starting position is indicated by a VRB index number.

An apparatus for determining a search space, comprising at least a determination unit and a detection unit, wherein,

a determining unit for obtaining the number of candidate control channels and corresponding initial positions according to the polymerization degree, and determining the search spaces corresponding to different polymerization degrees,

when the downlink control channel of the mobile relay consists of L-16 CCEs, the number of the corresponding candidate control channels is 1 or 2; when the downlink control channel of the mobile relay consists of L-32 CCEs, the number of the corresponding candidate control channels is 1;

when the downlink control channel of the mobile relay consists of Λ ═ 16 VRB pairs, the number of the corresponding candidate control channels is 1 or 2; when the downlink control channel of the mobile relay consists of Λ ═ 32 VRB pairs, the number of the corresponding candidate control channels is 1;

the initial positions of the search spaces corresponding to different L and Lambda are fixed; or, semi-static notification by higher layer signaling;

and the detection unit is used for blindly detecting the downlink control channel in the search spaces corresponding to different polymerization degrees.

According to the technical scheme provided by the invention, the method comprises the steps of obtaining the number of candidate control channels and corresponding initial positions thereof according to the polymerization degree, and determining search spaces corresponding to different polymerization degrees; blind detecting a downlink control channel in search spaces corresponding to different polymerization degrees; when the downlink control channel of the mobile relay consists of L ═ 16 CCEs, the number of the corresponding candidate control channels is 1 or 2; when the downlink control channel of the mobile relay consists of L-32 CCEs, the number of the corresponding candidate control channels is 1; when the downlink control channel of the mobile relay consists of Λ ═ 16 VRB pairs, the number of the corresponding candidate control channels is 1 or 2; when the downlink control channel of the mobile relay consists of Λ ═ 32 VRBpair, the number of the corresponding candidate control channels is 1; the initial positions of the search spaces corresponding to different L and Lambda are fixed; or semi-statically notified by higher layer signaling. The method solves the problem of how to search the own downlink control channel by the mobile relay in a high-speed mobile scene. The method is well suitable for mobile relays (or terminals of higher versions), greatly simplifies the detection complexity of the in-band/out-of-band relay node on the downlink control channel, is well suitable for the relay node, saves the system overhead and improves the transmission efficiency of the system.

Drawings

Fig. 1 is a diagram illustrating that a Un Link and a Uu Link use the same frequency band for an in-band relay node in the prior art;

FIG. 2 is a diagram illustrating an R-PDCCH sent by an eNB to an RN in the prior art;

fig. 3 is a schematic diagram illustrating that a Un Link and a Uu Link use different frequency bands for an out-of-band relay node in the prior art;

FIG. 4 is a flow chart of determining a search space according to the present invention;

FIG. 5 is a schematic diagram of the structure of the device for determining multiple spaces according to the present invention.

Detailed Description

Fig. 4 is a flowchart of determining a search space according to the present invention, as shown in fig. 4, including the following steps:

step 400: obtaining the number of candidate control channels and corresponding initial positions thereof according to the polymerization degree, and determining search spaces corresponding to different polymerization degrees; wherein,

in the case of interleaving, when a downlink control channel of a mobile relay consists of L ═ 16 CCEs, the number of the corresponding candidate control channels is 1 or 2; when the downlink control channel of the mobile relay consists of L-32 CCEs, the number of the corresponding candidate control channels is 1;

under the non-interleaving condition, when a downlink control channel of the mobile relay consists of Λ ═ 16 VRB pairs, the number of the corresponding candidate control channels is 1 or 2; when the downlink control channel of the mobile relay consists of Λ ═ 32 VRB pairs, the number of the corresponding candidate control channels is 1;

It should be noted that the downlink control channel of the outband mobile relay may be composed of L CCEs, or may be composed of Λ VRBpair, where the values of L and Λ may be any combination of 1,2,4,8,16, or 32. When the aggregation degree value is 1 or 2 or 4 or 8, the method for determining the number of candidate control channels is completely consistent with that in the prior art, and is not described herein again.

Step 401: and blindly detecting the downlink control channel in the search spaces corresponding to different polymerization degrees.

In this step, the starting positions of the search spaces corresponding to different L and Λ may be fixed, or may be notified by a high-level signaling in a semi-static manner. Wherein,

for the in-band non-interleaving case, the starting positions of the search spaces corresponding to different Λ may all be the same; or different from each other; or some of them are the same and some of them are different; the starting position is indicated by a VRB index number.

For the inband interleaving case, the starting positions of the search spaces corresponding to different L may be referred to the specification in the existing protocol, and are not used to limit the protection scope of the present invention, and are not described in detail here.

For the downlink control channel of the outband mobile relay, the downlink control channel is composed of L CCEs, and the starting positions of search spaces corresponding to different L are as follows:

the base station fixes the initial position of the search space of each outband mobile relay under the base station as a specific CCE index number; alternatively, the starting CCE index number is semi-statically variable and is signaled by a higher layer to the starting CCE index number and the total number of CCEs. At the moment, each out-of-band moving relay carries out blind detection in sequence from the initial CCE index number of each out-of-band moving relay, and the largest CCE index number in the search space cannot exceed the total number of CCEs; or,

the base station respectively allocates a group of fixed CCEs for each out-of-band mobile relay under the base station to bear the downlink control channel of the base station. In this case, the range of the search space is limited to the set of fixed CCEs, each out-of-band mobile relay performs blind detection in each search space range, and the starting positions of the search spaces corresponding to different ls are all the 1 st CCEs in each search space range. The set of CCEs may be fixed or semi-statically changed and signaled by higher layer signaling; or,

the base station sets a group of CCE index numbers occupied by the downlink control channels of the mobile relay with the out-of-band as fixed values or semi-statically variable, and notifies the fixed values by high-level signaling. In this case, the search space of each outband mobile relay is the set of CCEs pre-allocated, and blind detection is not required.

When the downlink control channel of the out-of-band mobile relay is composed of Λ VRB pair, the initial positions of the search spaces corresponding to different Λ are completely consistent with the in-band non-interleaving determination method, and detailed description is omitted here.

The method greatly simplifies the detection complexity of the in-band/out-of-band relay node for the downlink control channel, is well suitable for the relay node, saves the system overhead and improves the transmission efficiency of the system.

For the method of the present invention, there is also provided an apparatus for determining a search space, comprising at least a determining unit and a detecting unit, wherein,

The process of the present invention will be described in detail with reference to examples.

In the first embodiment, the in-band non-interleaving is the case where the start positions of the search spaces are the same. In this embodiment, it is assumed that the mobile relays belong to in-band relays, and R-PDCCHs of respective mobile relays under the coverage of the same base station are non-interleaved. The base station utilizes high-level signaling to configure 40 VRB pair semi-statically in advance for the mobile relay to carry R-PDCCH, and the numbers are VRB0, VRB1, … and VRB39 respectively. The 40 VRB pairs are logically continuous, but may be continuous or discrete physically according to the mapping manner of VRBs to PRBs.

The determining of each mobile relay search space comprises:

if the value of the base station configuration Λ is {1,2,4,8,16,32}, the number of the corresponding R-PDCCH candidates is {6 or 8 or 10, 2 or 3 or 4, 1 or 2, 1}, respectively.

The initial positions of the search spaces corresponding to different Λ are all the same, for example, it is assumed in this embodiment that the initial positions of the search spaces corresponding to all Λ are VRB 0;

the specific blind test process is as follows:

the mobile relay starts from Λ ═ 1, and starts from VRB0 to detect according to a group of 1-VRBs, and the corresponding R-pdcchcandidates are 6 or 8 or 10, that is, 6 or 8 or 10 times in total;

the search space is: { VRB0, VRB1, …, VRB5}, or { VRB0, VRB1, …, VRB7}, or { VRB0, VRB1, …, VRB9 }; the corresponding search space sizes are respectively: 6 or 8 or 10 VRBs.

If the mobile relay does not detect the R-PDCCH matched with the ID of the mobile relay, continuously detecting according to a group of 2-VRB from Λ -2, wherein the number of the corresponding R-PDCCH candidates is 6 or 8 or 10, namely detecting for 6 or 8 or 10 times;

the search space is: { { VRB0, VRB1}, { VRB2, VRB3} …, { VRB10, VRB11} }, or { { VRB0, VRB1}, { VRB2, VRB3} …, { VRB14, VRB15} }, or { { VRB0, VRB1}, { VRB2, VRB3} …, { VRB18, VRB19} }; the corresponding search space sizes are respectively: 12 or 16 or 20 VRBs.

If the mobile relay does not detect the R-PDCCH matched with the ID of the mobile relay, continuously detecting according to a group of 4-VRB from Λ ═ 4, wherein the number of the corresponding R-PDCCH candidates is 2, 3 or 4, namely, the detection is carried out for 2, 3 or 4 times;

the search space is: { { VRB0, VRB1, VRB2, VRB3}, { VRB4, VRB5, VRB6, VRB7} }, or { { VRB0, VRB1, VRB2, VRB3}, { VRB4, VRB5, VRB6, VRB7}, { VRB8, VRB9, VRB10, VRB11} }, or { { VRB0, VRB1, VRB2, VRB3}, { VRB4, VRB5, VRB6, VRB7}, { VRB8, VRB9, VRB10, VRB11}, { VRB12, VRB13, VRB14, VRB15 }; the corresponding search space sizes are respectively: 8 or 12 or 16 VRBs.

If the mobile relay does not detect the R-PDCCH matched with the ID of the mobile relay, continuously detecting according to a group of 8-VRB from Λ -8, wherein the number of the corresponding R-PDCCH candidates is 2, 3 or 4, namely, the detection is carried out for 2, 3 or 4 times;

the search space is: { { VRB0, VRB1, …, VRB7}, { VRB8, VRB9, …, VRB15} }, or { { VRB0, VRB1, …, VRB7}, { VRB8, VRB9, …, VRB15}, { VRB16, VRB17, …, VRB23} }, or { { VRB0, VRB1, …, VRB7}, { VRB8, VRB9, …, VRB15}, { VRB16, VRB17, …, VRB23}, { VRB24, VRB25, …, VRB31} }; the corresponding search space sizes are respectively: 16 or 24 or 32 VRBs.

If the MR does not detect the R-PDCCH matched with the ID of the MR, the detection is continuously carried out according to a 16-VRB group from Λ -16, and the corresponding R-PDCCH candidates are 1 or 2, namely 1 or 2 times in total;

the search space is: { VRB0, VRB1, …, VRB15}, or { { VRB0, VRB1, …, VRB15}, { VRB16, VRB17, …, VRB31} }; the search space size is 16 or 32 VRBs.

If the mobile relay does not detect the R-PDCCH matched with the ID of the mobile relay, continuously detecting according to a group of 32-VRB from Λ ═ 32, wherein the number of the corresponding R-PDCCH candidates is 1, namely detecting for 1 time in total;

the search space is: { VRB0, VRB1, …, VRB31 }; the search space size is 32 VRBs.

In any of the above VRB combination detection procedures, the mobile relay stops detection once it detects the R-PDCCH matching its own ID.

In a second embodiment, the in-band non-interleaving is the case where the starting positions of the search spaces are different. In this embodiment, if the value of the base station configuration Λ is {4,8,16,32}, the number of the corresponding R-PDCCH candidates is {2,2,1,1 }. Starting positions of the search spaces corresponding to different Λ are different, for example, the starting position of the search space corresponding to Λ ═ 4 is VRB 28; starting positions of the search spaces corresponding to the lambda-8 are all VRB 24; the initial position of the search space corresponding to lambda-16 is VRB 16; starting positions of the search spaces corresponding to the lambda-32 are all VRB 0;

the specific blind test process is as follows:

the mobile relay starts to detect according to a 4-VRB group from Λ ═ 4, and the number of corresponding R-PDCCH candidates is 2, namely 2 times of detection;

the search space is: { { VRB28, VRB29, VRB30, VRB31}, { VRB32, VRB33, VRB34, VRB35} }; the corresponding search spaces are respectively 8 VRBs in size.

If the mobile relay does not detect the R-PDCCH matched with the ID of the mobile relay, continuously detecting according to a group of 8-VRB from Λ -8, wherein the number of the corresponding R-PDCCH candidates is 2, namely detecting for 2 times;

the search space is: { { VRB24, VRB25, …, VRB31}, { VRB32, VRB33, …, VRB39} }; the corresponding search space sizes are 16 VRBs, respectively.

If the mobile relay does not detect the R-PDCCH matched with the ID of the mobile relay, continuously detecting according to a 16-VRB group from Λ ═ 16, wherein the number of the corresponding R-PDCCH candidates is 1, namely 1 time in total;

the search space is: { VRB16, VRB17, …, VRB31 }; the search space size is 16 VRBs.

A third embodiment, inband interleaving. In this embodiment, it is assumed that the mobile relays belong to in-band relays, and R-PDCCHs of the mobile relays under the coverage of the same base station are interleaved with each other. At this time, the determination of the search space is basically the same as the determination method of the search space of the UE in the current LTE/LTE-a. The difference is that when L is 16, the number of corresponding R-PDCCH candidates is 1 or 2, and when L is 32, the number of corresponding R-PDCCH candidates is 1.

In the fourth embodiment, out-of-band non-interleaving is performed, and the downlink control channel of the mobile relay is composed of L CCEs. In this embodiment, the mobile relay belongs to an out-of-band relay, and downlink control channels of 4 mobile relays under the coverage of the same base station are non-interleaved and are composed of L CCEs, where L belongs to {4,8,16,32 }. At this time, the downlink control channel of the mobile relay is carried on the first OFDM symbols of the 1 st slot of each subframe.

In this embodiment, it is assumed that the base station fixes the starting position of the search space of the 4 subjacent MRs to a certain CCE index, and the CCE index may also be semi-static and variable, that is:

for example, the starting positions of the search spaces of MR1, MR2, MR3, and MR4 are CCE0, CCE16, CCE20, and CCE55, respectively. At this time, each MR needs to start blind detection from the respective starting CCE index number, and the search space cannot exceed the total number of CCEs.

In this embodiment, assuming that the total number of CCEs is 80, each MR is notified by higher layer signaling.

Taking the blind detection process of MR1 as an example, the method includes:

the MR1 starts from L-4, and starts from CCE0 to perform detection according to a group of 4-CCEs, and the corresponding candidate control channels are 2, 3 or 4, that is, 2, 3 or 4 times in total;

the corresponding search space is: { { CCE, CCE, CCE, CCE }, { CCE, CCE, CCE } }, or { { CCE, CCE, CCE }, { CCE, CCE, CCE, CCE }, { CCE, CCE, CCE, CCE } }; the search space size is: 8 or 12 or 16 CCEs.

If the MR1 does not detect the downlink control channel matched with its own ID, continuing to detect by 8-CCE group from L-8, and detecting 2 or 3 or 4 corresponding candidate control channels, that is, detecting 2 or 3 or 4 times in total;

the corresponding search space is: { { CCE0, CCE1, …, CCE7}, { CCE8, CCE9, …, CCE15} }, or { { CCE0, CCE1, …, CCE7}, { CCE8, CCE9, …, CCE15}, { CCE16, CCE17, …, CCE23} }, or { { CCE0, CCE1, …, CCE7}, { CCE8, CCE9, …, CCE15}, { CCE16, CCE17, …, CCE23}, { 24, CCE25, …, CCE31} }; the search space size is: 16 or 24 or 32 CCEs.

If the MR1 does not detect the downlink control channel matched with its own ID, the detection is continued from L-16 according to a group of 16-CCEs, and the number of corresponding candidate control channels is 1 or 2, that is, the detection is performed for 1 or 2 times;

the corresponding search space is: { { CCE0, CCE1, …, CCE15} }, or { { CCE0, CCE1, …, CCE15}, { CCE16, CCE17, …, CCE31} }; the search space size is: 16 or 32 CCEs.

If the MR1 does not detect the downlink control channel matched with its own ID, continuing to detect by 32-CCE group from L-32, and detecting the corresponding candidate control channels by 1, that is, detecting for 1 time in total;

the corresponding search space is: { { CCE0, CCE1, …, CCE31} }; the search space size is: 32 CCEs.

In any of the above CCE combination detection processes, the MR stops blind detection once it detects the R-PDCCH matching its own ID.

Taking the blind detection of MR4 as an example, the procedure is as follows:

the MR4 starts from L-4, and starts from CCE20 to perform detection according to a group of 4-CCEs, and the corresponding candidate control channels are 2, 3 or 4, that is, 2, 3 or 4 times in total;

If MR4 does not detect the downlink control channel matching its own ID, it continues to detect by 8-CCE group starting from L-8, and the corresponding candidate control channels are 2 or 3, that is, 2 or 3 times in total. Note that: when the candidate control channel is 4, the search space may exceed the total number of CCEs, and thus, in this case, the candidate control channels can be only 2 or 3.

The corresponding search space is: { { CCE55, CCE56, …, CCE62}, { CCE63, CCE64, …, CCE70} }, or { { CCE55, CCE56, …, CCE62}, { CCE63, CCE64, …, CCE70}, { CCE71, CCE72, …, CCE78} }; the search space size is: 16 or 24 CCEs.

If MR4 does not detect the downlink control channel matching its own ID, it continues to detect by 16-CCE group starting from L-16, and the corresponding candidate control channels are 1 or 2, that is, 1 or 2 times in total. Note that: when the candidate control channel is 2, the search space may exceed the total number of CCEs, and thus, in this case, the candidate control channel can be only 1.

The corresponding search space is: { CCE55, CCE56, …, CCE70 }; the search space size is: 16 CCEs.

Since the total number of CCEs is 80, MR4 does not detect Λ 32, i.e., stops detecting Λ 16.

In any CCE combination detection process, the MR stops blind detection once it detects a downlink control channel matching its own ID.

In this embodiment, it is assumed that the base station configures a set of fixed CCEs for carrying their respective downlink control channels for their subordinate 4 MRs, and the range of the search space is limited within the set of CCEs. For example:

1) the search space range of MR1 is defined in { CCE0, CCE1, …, CCE15 }; the search space range of MR2 is defined in { CCE20, VCCE21, …, CCE51 }; the search space range of MR3 is defined in { CCE55, CCE56, …, CCE62 }; the search space range of MR4 is defined in { CCE65, CCE66, …, CCE80 }.

2) The starting positions of the search spaces corresponding to different L are all the same, and the starting position of the search space corresponding to each L is the 1 st CCE in the range of the search space. For MR1, the starting position of the search space corresponding to each L is CCE 0; for MR2, the starting position of the search space corresponding to each L is CCE 20; for MR3, the starting position of the search space corresponding to each L is CCE 55; for MR3, the starting position of the search space corresponding to each L is CCE 65.

Taking the blind detection of MR1 as an example, the procedure is as follows:

If MR1 does not detect the downlink control channel matching its own ID, it continues to detect by 8-CCE group starting from L-8, and the corresponding candidate control channels are 2, that is, 2 times in total. Note that: when the candidate control channel is 3 or 4, the search space is beyond the pre-allocated range of the base station, and therefore, in this case, the candidate control channel can only be 2.

The corresponding search space is: { { CCE0, CCE1, …, CCE7}, { CCE8, CCE9, …, CCE15} }; the search space size is 16 CCEs.

If MR1 does not detect the downlink control channel matching its own ID, it continues to detect by 16-CCE group starting from L-16, and the corresponding candidate control channels are 1 or 2, that is, 1 or 2 times in total. Note that: when the candidate control channel is 2, the search space is beyond the pre-allocated range of the base station, so in this case, the candidate control channel can only be 1.

The corresponding search space is: { { CCE0, CCE1, …, CCE15} }; the search space size is: 16 CCEs.

Since the range of the search space of MR1 is limited to CCE0 to CCE15, MR1 does not detect Λ 32, that is, stops detecting Λ 16.

In any of the above CCE combination detection processes, the MR stops blind detection once it detects a downlink control channel matching its own ID.

Similarly, the search spaces of MR2, MR3, and MR4 are determined as MR1, as long as the range of the search space pre-allocated by the base station is not exceeded.

In this embodiment, it is assumed that the base station sets CCE index numbers occupied by downlink control channels of 4 subordinate MRs to a fixed value or semi-statically variable respectively, and notifies the CCE index numbers by using a high-level signaling.

For example, the downlink control channel of MR1 consists of 16 CCEs, and the CCE index number occupied is fixed to { CCE0 to CCE15 }; the downlink control channel of MR2 is composed of 32 CCEs, and the index number of the occupied CCE is fixed to { CCE 20-CCE 51 }; the downlink control channel of MR3 is composed of 4 CCEs, and the index number of the occupied CCE is fixed to { CCE 16-CCE 19 }; the downlink control channel of MR4 is composed of 8 CCEs, and the index number of the occupied CCE is fixed to { CCE 56-CCE 63 }. Note that: when the base station allocates the CCE index numbers to the subordinate MRs, it is ensured that the CCE index numbers of the MRs do not overlap.

At this time, the MR can obtain its own downlink control information by receiving and demodulating the allocated set of CCEs without performing blind detection.

In addition, the CCE index number occupied by the downlink control channel of each MR may be a fixed value or a semi-statically changed value, and the updated value of each MR needs to be notified by using a high-level signaling.

In the fifth embodiment, the outband is not interlaced, and the downlink control channel of the mobile relay is composed of Λ VRBs. The only difference is that, like the first and second embodiments: the definition of out-of-band and in-band VRB pair is different. Size of out-of-band VRB pair: occupying 12 REs in the frequency domain and all OFDM symbols of the entire subframe in the time domain. And size of the in-band VRB pair: still occupy 12 REs in the frequency domain, but remove-max (OFDM symbol occupied by PDCCH sent by base station for macro cell UE, OFDM symbol occupied by PDCCH sent by in-band relay for its subordinate UE) in the time domain.

A sixth embodiment, out-of-band interleaving. In this embodiment, the MRs belong to an out-of-band relay, and downlink control channels of the MRs under the coverage of the same base station are interleaved. At the moment, the determination method of the search space is basically consistent with the determination method of the search space of the UE in the current LTE/LTE-A; the difference is that the number of the candidate control channels corresponding to L-16 is 1 or 2, and the number of the candidate control channels corresponding to L-32 is 1. The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, and any modifications, equivalents, improvements, etc. that are within the spirit and principle of the present invention should be included in the present invention.

Claims

1. A method of determining a search space, comprising,

when the downlink control channel of the mobile relay consists of L ═ 16 CCEs, the number of the corresponding candidate control channels is 1 or 2; when the downlink control channel of the mobile relay consists of L-32 CCEs, the number of the corresponding candidate control channels is 1; when the downlink control channel of the mobile relay consists of the VRB pair with Λ being 16 virtual resource blocks, the number of the corresponding candidate control channels is 1 or 2; when the downlink control channel of the mobile relay consists of Λ ═ 32 VRB pairs, the number of the corresponding candidate control channels is 1;

wherein, the values of L and Λ are respectively: 1 or 2 or 4 or 8 or 16 or 32.

2. The method of claim 1, wherein for the case of in-band non-interleaving, the starting positions of the search spaces corresponding to different Λ are the same; or, differently; or, some are the same and the remainder are different;

the starting position is indicated by a VRB index number.

3. The method of claim 1, wherein a downlink control channel for the outband mobile relay is composed of L CCEs, and starting positions of the search spaces corresponding to different L are as follows:

4. The method of claim 1, wherein a downlink control channel for the outband mobile relay is composed of L CCEs, and starting positions of the search spaces corresponding to different L are as follows:

5. The method of claim 1, wherein a downlink control channel for the outband mobile relay is composed of L CCEs, and starting positions of the search spaces corresponding to different L are as follows:

the search space of each outband mobile relay is a pre-allocated group of CCEs.

6. The method of claim 1, wherein when the downlink control channel of the outband mobile relay is composed of Λ VRB pairs, the initial positions of the search spaces corresponding to different Λ are the same; or, differently; or, some are the same and the remainder are different;

the starting position is indicated by a VRB index number.

7. An apparatus for determining a search space, comprising at least a determining unit and a detecting unit, wherein,

when the downlink control channel of the mobile relay consists of the VRB pair with Λ being 16 virtual resource blocks, the number of the corresponding candidate control channels is 1 or 2; when the downlink control channel of the mobile relay consists of Λ ═ 32 VRB pairs, the number of the corresponding candidate control channels is 1;

the detection unit is used for blindly detecting the downlink control channel in the search spaces corresponding to different polymerization degrees;

wherein, the values of L and Λ are respectively: 1 or 2 or 4 or 8 or 16 or 32.