TRANSMISSION OF CONTROL CHANNEL AND DATA CHANNELS FOR COVERAGE ENHANCEMENTS

• US 20150131579A1
• Filed: 11/11/2014
• Published: 05/14/2015
• Est. Priority Date: 11/13/2013
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Li, Ying, Papasakellariou, Aris
• Granted Patent: US 9,667,386 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 1/0072 Error control for data other than payload data, e.g. control data
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1845 Combining techniques, e.g. code combining
• CPC Class Codes: H04L 1/1858 Transmission or retransmission of more than one copy of acknowledgement message
• CPC Class Codes: H04L 1/189 Transmission or retransmission of more than one copy of a message
• CPC Class Codes: H04W 52/0212 managed by the network, e.g. network or access point is master and terminal is slave
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Methods and apparatus are provided for a base station to transmit and for a User Equipment (UE) to receive repetitions of an enhanced physical downlink control channel (EPDCCH). Time and frequency resources for EPDCCH repetitions are defined together with restrictions in time resources to provide UE power savings. Time and frequency resources are also defined for repetitions of a physical downlink shared channel (PDSCH) transmission and for repetitions of a physical uplink shared channel (PUSCH) transmission. Methods and apparatus are also provided for the UE to transmit and for the base station to receive acknowledgement information in repetitions of a physical uplink shared channel (PUCCH).

Claims

1. A method comprising:

mapping, by a base station, a first repetition for a transmission of an enhanced physical downlink control channel (EPDCCH) in a sub-frame (SF) with index n_s, wherein the SF is located in a frame that includes ten SFs and has system frame number (SFN) Z, and is determined as ((Z−

Z₀)·

D+n_s−

n_s0)mod(N_EPDCCH+Gap_EPDCCH) where Z₀ is a SFN offset with 0≦

Z₀<

1024, n_s0 is a SF offset with 0≦

n_s0<

10, D is a number of SFs within a frame where the base station transmits an EPDCCH repetition with 0<

D≦

10, N_EPDCCH is a number of SFs with repetitions of the EPDCCH transmission, and Gap_EPDCCH is an offset; and

transmitting, by the base station to a User Equipment (UE), the repetitions of the EPDCCH in N_EPDCCH SFs.

2. The method of claim 1, wherein at least one of:

Z₀=0, or n_s0=0.

3. The method of claim 1, wherein the SFs in which the base station transmits the EPDCCH repetitions or the value of D can be determined by the UE based on higher layer signaling transmitted by the base station.

4. The method of claim 1, wherein for a frequency division duplex system, the EPDCCH is configured to convey a downlink control information (DCI) format scheduling at least one of:

a transmission of a data channel from the base station to the UE, wherein the data channel transmission includes repetitions in a number of N_PUSCH SFs, or

a transmission of a data channel from the UE to the base station, wherein the data channel transmission includes repetitions in a number of N_PUSCH SFs, and wherein a larger of N_PUSCH and N_PUSCH+5 is a Gap_EPDCCH, and wherein the values of N_EPDCCH, N_PDSCH, and N_PUSCH are configured to the UE by the base station using radio resource control signaling.

5. The method of claim 4, wherein when multiple values of N_EPDCCH, and N_PDSCH are configured, the multiple values of N_EPDCCH have a one-to-one mapping with the multiple values of N_PDSCH and a value of N_PDSCH is adapted to be determined from the value of N_EPDCCH that is used by the UE detect the DCI format.

6. The method of claim 1, wherein a drx-InactivityTimer having a unit of N_EPDCCH+Gap_EPDCCH SFs is applied to determine a time period of a discontinuous reception (DRX) state.

7. A method comprising:

mapping, by a base station, a first repetition for a transmission of an enhanced physical downlink control channel (EPDCCH) conveying a downlink control information (DCI) format in a first sub-frame (SF), a first set of frequency resources, and a first set of enhanced control channel elements (ECCEs) and a second repetition in a second SF, a second set of frequency resources, and a second set of ECCEs, wherein the first set of ECCEs and the second set of ECCEs include a same number of ECCEs and the first frequency resources are different than the second frequency resources; and

transmitting, by the base station to a User Equipment (UE), the first EPDCCH repetition and the second EPDCCH repetition.

8. The method of claim 7, wherein the base station configures the UE by radio resource control signaling, a first number of repetitions and a second number of repetitions for receiving the EPDCCH transmission in the first SF and in the first set of frequency resources, and wherein the EPDCCH transmission includes either a repetition from the first number of repetitions in the first set of ECCEs or a repetition from the second number of repetitions in a third set of ECCEs, wherein the first set of ECCEs and the third set of ECCEs include a same number of ECCEs and the first set of ECCEs has at least one ECCE that is not in the third set of ECCEs.

9. The method of claim 7, wherein the possible numbers of ECCEs used to transmit a first DCI format in a first EPDCCH without repetitions is larger than the possible numbers of ECCEs used to transmit a second DCI format in a second EPDCCH with repetitions.

10. A method comprising:

mapping, by a User Equipment (UE), a first repetition of a physical uplink control channel (PUCCH) transmission in a first PUCCH resource in a first sub-frame (SF) and a second repetition of the PUCCH transmission in a second PUCCH resource in a second SF,

wherein the PUCCH transmission conveys hybrid automatic repeat request acknowledgement (HARQ-ACK) information in response to a reception by the UE of a data transport block in a physical downlink shared channel (PDSCH) scheduled by a downlink control information (DCI) format transmitted in an enhanced physical control channel (EPDCCH) that consists of enhanced control channel elements (ECCEs), and

wherein, if the UE is of a first type, the UE determines the first PUCCH resource from an ECCE with a lowest index among the ECCEs of the EPDCCH and the second resource is configured to the UE from the base station by radio resource signaling and wherein, if the UE is of a second type, the UE determines the first PUCCH resource to be same as the second PUCCH resource as configured to the UE from the base station by radio resource signaling; and

transmitting, by the UE to the base station, the first repetition of the PUCCH transmission and the second repetition of the PUCCH transmission.

11. The method of claim 10, wherein the SF includes a first slot and a second slot, and wherein the UE of the first type transmits a PUCCH in the first slot in a different frequency resource block than in the second slot and the UE of the second type transmits a PUCCH in a subframe in a same frequency resource block.

12. A base station comprising:

a mapper configured to map a first repetition for a transmission of an enhanced physical downlink control channel (EPDCCH) in a sub-frame (SF) with index n_s, wherein the SF is located in a frame that includes ten SFs and has system frame number (SFN) Z, and is determined as ((Z−

Z₀)·

D+n_s−

n_s0)mod(N_EPDCCH+Gap_EPDCCH) where Z₀ is a SFN offset with 0≦

Z₀<

1024, n_s0 is a SF offset with 0≦

n_s0<

10, D is a number of SFs within a frame where the base station transmits an EPDCCH repetition with 0<

D≦

10, N_EPDCCH is a number of SFs with repetitions of the EPDCCH transmission, and Gap_EPDCCH is an offset; and

a transmitter configured to transmit the repetitions of the EPDCCH in N_EPDCCH SFs.

13. A User Equipment (UE) comprising:

a receiver configured to receive up to N_EPDCCH repetitions in respective sub-frames (SFs) for a transmission of an enhanced physical control channel (EPDCCH); and

a mapper configured to map the first repetition of the EPDCCH in a SF with index n_s, wherein the SF is located in a frame that includes ten SFs and has system frame number (SFN) Z, and is determined as ((Z−

Z₀)·

D+n_s−

n_s0)mod(N_EPDCCH+Gap_EPDCCH)=0, where Z₀ is a SFN offset with 0≦

Z₀<

1024, n_s0 is a SF offset with 0≦

n_s0<

10, D is a number of SFs within a frame where the base station transmits an EPDCCH repetition with 0<

D≦

10, and Gap_EPDCCH is an offset.

14. The apparatus of claim 13, wherein the UE is configured to determine the value of D and SFs to receive the N_EPDCCH repetitions based on higher layer signaling from a base station wherein the higher layer signaling includes a bit-map having 10 binary elements with a one-to-one mapping to the 10 SFs of a frame, and wherein if a binary value of the bit-map is ‘

0’

, the UE receives the EPDCCH repetition in the respective SF and if a binary value of the bit-map is ‘

1’

, the UE receives the EPDCCH repetition in the respective SF.

15. A base station comprising:

a mapper configured to map a first repetition for a transmission of an enhanced physical downlink control channel (EPDCCH) in a first sub-frame (SF), a first set of frequency resources, and a first set of enhanced control channel elements (ECCEs) and a second repetition in a second SF, a second set of frequency resources, and a second set of ECCEs, wherein the first set of ECCEs and the second set of ECCEs include a same number of ECCEs and the first frequency resources are different than the second frequency resources; and

a transmitter configured to transmit the first EPDCCH repetition and the second EPDCCH repetition.

16. A User Equipment (UE) comprising:

a receiver configured to receive a first repetition and a second repetition of an enhanced physical downlink control channel (EPDCCH) transmission; and

a mapper configured to map the first repetition in a first sub-frame (SF), a first set of frequency resources, and a first set of enhanced control channel elements (ECCEs) and the second repetition in a second SF, a second set of frequency resources, and a second set of ECCEs, wherein the first set of ECCEs and the second set of ECCEs include a same number of ECCEs and the first frequency resources are different than the second frequency resources.

17. The apparatus of claim 16, wherein the UE is configured, by radio resource control signaling from a base station, a first number of repetitions for receiving the EPDCCH transmission and a second number of repetitions for receiving the EPDCCH transmission, and wherein in the first SF and in the first set of frequency resources, the UE receives a candidate EPDCCH repetition from the first number of repetitions in the first set of ECCEs and receives a candidate EPDCCH repetition from the second number of repetitions in a third set of ECCEs, wherein the first set of ECCEs and the third set of ECCEs include a same number of ECCEs and the first set of ECCEs has at least one ECCE that is not in the third set of ECCEs.

18. A User Equipment (UE) comprising:

a mapper configured to map a first repetition of a physical uplink control channel (PUCCH) transmission in a first PUCCH resource in a first sub-frame (SF) and a second repetition of the PUCCH transmission in a second PUCCH resource in a second SF,

wherein the PUCCH transmission conveys hybrid automatic repeat request acknowledgement (HARQ-ACK) information in response to a reception by the UE of a data transport block in a physical downlink shared channel (PDSCH) scheduled by a downlink control information (DCI) format transmitted in an enhanced physical control channel (EPDCCH) that consists of enhanced control channel elements (ECCEs), and

wherein, if the UE is of a first type, the UE determines the first PUCCH resource from an ECCE with a lowest index among the ECCEs of the EPDCCH and the second resource is configured to the UE from the base station by radio resource signaling and wherein, if the UE is of a second type, the UE determines the first PUCCH resource to be same as the second PUCCH resource as configured to the UE from the base station by radio resource signaling; and

a transmitter configured to transmit the first repetition of the PUCCH transmission and the second repetition of the PUCCH transmission.

19. The apparatus of claim 18, wherein the SF includes a first slot and a second slot, and wherein the UE of the first type transmits a PUCCH in the first slot in a different frequency resource block than in the second slot and the UE of the second type transmits a PUCCH in a subframe in a same frequency resource block.

20. A base station comprising:

a receiver configured to receive a first repetition of a physical uplink control channel (PUCCH) transmission and a second repetition of the PUCCH transmission; and

a mapper configured to map the first repetition of the PUCCH transmission in a first PUCCH resource in a first sub-frame (SF) and a second repetition of the PUCCH transmission in a second PUCCH resource in a second SF,

wherein the PUCCH transmission conveys hybrid automatic repeat request acknowledgement (HARQ-ACK) information in response to a transmission by the base station of a data transport block in a physical downlink shared channel (PDSCH) scheduled by a downlink control information (DCI) format transmitted by the base station in an enhanced physical control channel (EPDCCH) that consists of enhanced control channel elements (ECCEs), and

wherein, if the PUCCH transmission is from a User Equipment (UE) is of a first type, the base station determines the first PUCCH resource from an ECCE with a lowest index among the ECCEs of the EPDCCH and the second resource is configured from the base station and wherein, if the PUCCH transmission is from a UE of a second type, the base station determines the first PUCCH resource to be same as the second PUCCH resource and configured from the base station.

21. The apparatus of claim 20, wherein the SF includes a first slot and a second slot, and wherein the base station receives UE a PUCCH in the first slot in a different frequency resource block than in the second slot if the PUCCH is transmitted from a UE of the first type and the base station receives a PUCCH in a subframe in a same frequency resource block if the PUCCH is transmitted from a UE of the second type.