Method of transmitting scheduling request in a wireless communication system
A method of transmitting a scheduling request which is used to request a radio resource for uplink transmission includes configuring an uplink control channel for transmission of a scheduling request in a subframe, the subframe comprising two consecutive slots, a slot comprising a plurality of single carrier-frequency division multiple access (SC-FDMA) symbols, the scheduling request being carried by presence or absence of transmission of the uplink control channel, and transmitting the scheduling request on the uplink control channel.
1. A method of transmitting a scheduling request in a wireless communication system, the method comprising:
determining a subframe for transmitting the scheduling request, the subframe comprising two consecutive slots, each slot comprising a first set of orthogonal frequency division multiple access (OFDM) symbols and a second set of OFDM symbols, wherein the subframe is determined among subframes which belong to a transmission period of the scheduling request;
configuring an uplink control channel for transmitting the scheduling request; and
transmitting the scheduling request on the uplink control channel in the subframe, wherein configuring the uplink control channel comprises, for the OFDM symbols in each slot:
mapping a corresponding one of a plurality of frequency domain sequences to each OFDM symbol in the first set of OFDM symbols, thereby generating a first set of mapped frequency domain sequences;
mapping a corresponding one of the plurality of frequency domain sequences to each OFDM symbol in the second set of OFDM symbols, thereby generating a second set of mapped frequency domain sequences;
spreading the first set of mapped frequency domain sequences with a first orthogonal sequence, the first orthogonal sequence having a length equal to the number of OFDM symbols in the first set of OFDM symbols; and
spreading the second set of mapped frequency domain sequences associated with each of the OFDM symbols in the second set of OFDM symbols with a second orthogonal sequence, the second orthogonal sequence having a length equal to the number of OFDM symbols in the second set of OFDM symbols.
2. The method of claim 1 , wherein the first orthogonal sequence is a time domain sequence, and wherein spreading the first set of mapped frequency domain sequences comprises:
applying each element associated with the first orthogonal sequence to a corresponding one of the OFDM symbols in the first set of OFDM symbols.
3. The method of claim 1 , wherein the second orthogonal sequence is a time domain sequence, and wherein spreading the second set of mapped frequency domain sequences comprises:
applying each element associated with the second orthogonal sequence to a corresponding one of the OFDM symbols in the second set of OFDM symbols.
4. The method of claim 1 , wherein the subcarriers associated with each of the frequency domain sequences in one of the two consecutive slots of the subframe are different from the subcarriers associated with each of the frequency domain sequences in the second of the two consecutive slots of the subframe.
5. The method of claim 1 , wherein the length of each of the plurality of frequency domain sequences equals the number of subcarriers allocated to the OFDM symbols.
6. The method of claim 1 , wherein the number of OFDM symbols in the first set of OFDM symbols is greater than the number of OFDM symbols in the second set of OFDM symbols.
7. The method of claim 6 , wherein the number of OFDM symbols in one of the two consecutive slots is seven, the number of OFDM symbols in the first set of OFDM symbols is four and the number of OFDM symbols in the second set of OFDM symbols is three.
8. The method of claim 1 , wherein the OFDM symbols are single-carrier frequency division multiple access (SC-FDMA) symbols.
9. An apparatus for transmitting a scheduling request in a wireless communication system, the apparatus comprising:
means for determining a subframe for transmitting the scheduling request, the subframe comprising two consecutive slots, each slot comprising a first set of orthogonal frequency division multiple access (OFDM) symbols and a second set of OFDM symbols, wherein the subframe is determined among subframes which belong to a transmission period of the scheduling request;
means for configuring an uplink control channel to transmit the scheduling request; and
means for transmitting the scheduling request on the uplink control channel in the subframe, wherein said means for configuring the uplink control channel comprises, for the OFDM symbols in each slot:
means for mapping a corresponding one of a plurality of frequency domain sequences to each OFDM symbol in the first set of OFDM symbols, thereby generating a first set of mapped frequency domain sequences, wherein each of the plurality of frequency domain sequences comprises the same subcarriers, and wherein the sequence of the subcarriers associated with each of these frequency domain sequences is cycle shifted relative to the sequence of the subcarriers associated with each of the other of these frequency domain sequences;
means for mapping a corresponding one of the plurality of frequency domain sequences to each OFDM symbol in the second set of OFDM symbols, thereby generating a second set of mapped frequency domain sequences, wherein the sequence of the subcarriers associated with these frequency domain sequences is cycle shifted relative to the sequence of the subcarriers associated with each of the other of these frequency domain sequences;
means for spreading the first set of mapped frequency domain sequences with a first orthogonal sequence, the first orthogonal sequence having a length equal to the number of OFDM symbols in the first set of OFDM symbols; and
means for spreading the second set of mapped frequency domain sequences associated with each of the OFDM symbols in the second set of OFDM symbols with a second orthogonal sequence, the second orthogonal sequence having a length equal to the number of OFDM symbols in the second set of OFDM symbols.
10. The apparatus of claim 9 , wherein the first orthogonal sequence is a time domain sequence, and wherein said means for spreading the first set of mapped frequency domain sequences comprises:
means for applying each element associated with the first orthogonal sequence to a corresponding one of the OFDM symbols in the first set of OFDM symbols.
11. The apparatus of claim 9 , wherein the second orthogonal sequence is a time domain sequence, and wherein said means for spreading the second set of mapped frequency domain sequences comprises:
applying each element associated with the second orthogonal sequence to a corresponding one of the OFDM symbols in the second set of OFDM symbols.
12. The apparatus of claim 9 , wherein the subcarriers associated with each of the frequency domain sequences in one of the two consecutive slots of the subframe are different from the subcarriers associated with each of the frequency domain sequences in the second of the two consecutive slots of the subframe.
13. The apparatus of claim 9 , wherein the length of each of the plurality of frequency domain sequences equals the number of subcarriers allocated to the OFDM symbols.
14. The apparatus of claim 9 , wherein the number of OFDM symbols in the first set of OFDM symbols is greater than the number of OFDM symbols in the second set of OFDM symbols.
15. The apparatus of claim 14 , wherein the number of OFDM symbols in one of the two consecutive slots is seven, the number of OFDM symbols in the first set of OFDM symbols is four and the number of OFDM symbols in the second set of OFDM symbols is three.