Method and device for receiving broadcast information in communication system
Disclosed are a communication technique for merging, with IoT technology, a 5G communication system for supporting a data transmission rate higher than that of a 4G system, and a system therefor. The disclosed communication technique and system therefor can be applied to intelligent services (for example, smart home, smart building, smart city, smart car or connected car, health care, digital education, retail, security and safety related services, and the like) on the basis of 5G communication technology and IoT-related technology. The present disclosure relates to a method and a device for receiving, by a terminal, broadcast information in a communication system. According to an embodiment of the present disclosure, the method by which a terminal receives broadcast information in a communication system comprises the steps of: receiving a plurality of radio frames from a base station; extracting at least one broadcasting channel signal from the plurality of radio frames in every set period; combining, for a preset time slot, the at least one broadcasting channel signal extracted in every set period; and acquiring broadcast information by decoding the combined broadcasting channel signal.
1. A method of receiving broadcast information by a user equipment (UE) in a communication system, the method comprising:
setting a subframe among a radio frame as a combining window for extracting a broadcasting channel signal;
receiving a plurality of radio frames including the radio frame from a base station (BS);
extracting the broadcasting channel signal from the subframe corresponding to the combining window in every predetermined period in the plurality of radio frames;
accumulating one or more broadcasting channel signals extracted from the plurality of radio frames in the every predetermined period;
combining the one or more broadcasting channel signals accumulated for a preset time interval; and
acquiring broadcast information by decoding the combined broadcasting channel signal.
2. The method of claim 1 , wherein the UE is a UE for which an improvement in a communication coverage is required.
3. The method of claim 2 , further comprising:
when a time used for synchronization and a cell search is longer than a preset time based on a primary synchronization signal and a secondary synchronization signal included in the plurality of radio frames, identifying that the UE is the UE for which the improvement in the communication coverage is required.
4. The method of claim 2 , further comprising:
when reception power of a signal calculated based on a primary synchronization signal and a secondary synchronization signal included in the plurality of radio frames is smaller than a preset threshold value, identifying that the UE is the UE for which the improvement in the communication coverage is required.
5. The method of claim 1 , wherein the predetermined period corresponds to 1024 radio frames.
6. The method of claim 5 , wherein a number of one or more broadcasting channel signals accumulated is determined based on a number of subframes to which broadcasting channel signals including the broadcast information are mapped in the 1024 radio frames and on a number of preset subframes for extracting the broadcasting channel signal in the corresponding communication system.
7. The method of claim 5 , wherein a number of one or more broadcasting channel signals accumulated is one of 1, 4, and 8.
8. The method of claim 1 , wherein the broadcast information is included in a master information block (MIB).
9. The method of claim 8 , wherein the MIB includes downlink system frequency information, physical hybrid automatic retransmit request indicator channel setting information, and system frame number information.
10. The method of claim 1 , wherein the acquiring of the broadcast information further comprises:
outputting a master information block (MIB) bit sequence by decoding the combined broadcasting channel signal;
calculating cyclic redundancy check (CRC) bits using MIBs included in the output MIB bit sequence;
when CRC bits included in the output MIB bit sequence are identical to the calculated CRC bits based on a comparison therebetween, determining that the MIBs included in the output MIB bit sequence do not contain an error; and
acquiring the broadcast information from the MIBs included in the output MIB bit sequence.
11. An apparatus for receiving broadcast information by a user equipment (UE) in a communication system, the apparatus comprising:
a receiver configured to receive a plurality of radio frames from a base station (BS); and
at least one processor configured to:
set a subframe among a radio frame included in the plurality of radio frames, as a combining window for extracting a broadcasting channel signal,
extract the broadcasting channel signal from the subframe corresponding to the combining window in every predetermined period in the plurality of radio frames,
accumulate one or more broadcasting channel signals extracted from the plurality of radio frames in the every predetermined period,
combine the one or more broadcasting channel signals accumulated for a preset time interval, and
acquire broadcast information by decoding the combined broadcasting channel signal.
12. The apparatus of claim 11 , wherein the UE is required to improve a communication coverage.
13. The apparatus of claim 12 , wherein the at least one processor is further configured to identify that the UE is required to improve the communication coverage when a time used for synchronization and a cell search is longer than a preset time based on a primary synchronization signal and a secondary synchronization signal included in the plurality of radio frames.
14. The apparatus of claim 12 , wherein the at least one processor is further configured to identify that the UE is required to improve the communication coverage when reception power of a signal calculated based on a primary synchronization signal and a secondary synchronization signal included in the plurality of radio frames is smaller than a preset threshold value.
15. The apparatus of claim 11 , wherein the predetermined period corresponds to 1024 radio frames.
16. The apparatus of claim 15 , wherein a number of the one or more broadcasting channel signals accumulated is determined based on at least one of a number of subframes to which a broadcasting channel signal including the broadcast information is mapped in the 1024 radio frames, or a number of preset subframes for extracting the broadcasting channel signal in the corresponding communication system.
17. The apparatus of claim 15 , wherein a number of the one or more broadcasting channel signals accumulated is one of 1, 4, and 8.
18. The apparatus of claim 11 , wherein the broadcast information is included in a master information block (MIB).
19. The apparatus of claim 18 , wherein the MIB includes downlink system frequency information, physical hybrid automatic retransmit request indicator channel setting information, and system frame number information.
20. The apparatus of claim 11 , wherein the at least one processor is further configured to:
output a master information block (MIB) bit sequence by decoding the combined broadcasting channel signal,
calculate cyclic redundancy check (CRC) bits using MIB included in the output MIB bit sequence,
if CRC bits included in the output MIB bit sequence are identical to the calculated CRC bits based on a comparison therebetween, identify that the MIB included in the output MIB bit sequence do not contain an error, and
acquire the broadcast information from the MIB included in the output MIB bit sequence.