SINGLE-FREQUENCY NETWORK (SFN) OPERATION FOR MACHINE-TYPE COMMUNICATIONS (MTC) COVERAGE ENHANCEMENTS

• US 20170048821A1
• Filed: 10/31/2016
• Published: 02/16/2017
• Est. Priority Date: 02/13/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: XU, Hao, JI, Tingfang, GAAL, Peter, MALLADI, Durga Prasad, WEI, Yongbin, CHEN, Wanshi
• Granted Patent: US 9,888,457 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04L 1/0013 Rate matching, e.g. puncturing or repetition of code symbols
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 4/70 Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

Certain aspects of the present disclosure generally relate to wireless communications and, more particularly, to techniques for single-frequency network (SFN) operation for machine-type communications (MTC) coverage enhancements. A method is provided for wireless communications by a user equipment (UE). The method generally includes detecting a synchronization signal transmitted from at least one of a plurality of transmission points, wherein each of the plurality of transmission points transmits a synchronization signal at a different offset time relative to a subframe boundary in a synchronized network, determining a subframe occurring a fixed time after detecting the synchronization signal to monitor for system information transmitted from at least one of the plurality of transmission points, and monitoring for a system information block during the determined subframe.

Claims

1. A method for wireless communications, by a user equipment (UE), comprising:

receiving, in special subframes designated for UEs of a first type, reference signals transmitted from one or more transmission points using at least one entire symbol in a downlink subframe.

2. The method of claim 1, wherein:

multiple symbols per slot can be assigned for reference signals for UEs of the first type.

3. The method of claim 1, wherein reference signals for UEs of the first type are transmitted only in the first slot of a subframe.

4. The method of claim 1, wherein:

signals for UEs of a second type are also transmitted in the special subframes; and

the UE performs rate-matching around the signals for UEs of a second type.

5. The method of claim 1, wherein the reference signals are transmitted as single frequency network (SFN) transmissions from multiple cells.

6. A method for wireless communications, by a user equipment (UE), comprising:

transmitting a physical uplink shared channel (PUSCH); and

including, in the PUSCH, pilot symbols, wherein a number of symbols used for pilot symbols varies based on coverage of the UE.

7. The method of claim 6, wherein:

a number of symbols used for pilot symbols for UEs with good coverage is less than a number of symbols used for pilot symbols for UEs with worse coverage.

8. The method of claim 7, wherein at least one out of seven symbols are used as pilot symbols for UEs with good coverage and at least two out of seven symbols are used as pilot symbols for UEs with worse coverage.

9. The method of claim 6, wherein user multiplexing is allowed to improve loading.

10. An apparatus for wireless communications, by a user equipment (UE), comprising:

means for receiving, in special subframes designated for UEs of a first type, reference signals transmitted from one or more transmission points using at least one entire symbol in a downlink subframe.

11. The apparatus of claim 10, wherein:

multiple symbols per slot can be assigned for reference signals for UEs of the first type.

12. The apparatus of claim 10, wherein reference signals for UEs of the first type are transmitted only in the first slot of a subframe.

13. The apparatus of claim 10, wherein:

signals for UEs of a second type are also transmitted in the special subframes; and

the UE performs rate-matching around the signals for UEs of a second type.

14. The apparatus of claim 10, wherein the reference signals are transmitted as single frequency network (SFN) transmissions from multiple cells.

15. An apparatus for wireless communications, by a user equipment (UE), comprising:

means for transmitting a physical uplink shared channel (PUSCH); and

means for including, in the PUSCH, pilot symbols, wherein a number of symbols used for pilot symbols varies based on coverage of the UE.

16. The apparatus of claim 15, wherein:

a number of symbols used for pilot symbols for UEs with good coverage is less than a number of symbols used for pilot symbols for UEs with worse coverage.

17. The apparatus of claim 16, wherein at least one out of seven symbols are used as pilot symbols for UEs with good coverage and at least two out of seven symbols are used as pilot symbols for UEs with worse coverage.

18. The apparatus of claim 15, wherein user multiplexing is allowed to improve loading.