Method for transmitting control signal
There is provided a method of enabling a user equipment to transmit a control signal to a base station. The method includes allocating a control signal to a control region on a subframe comprising the control region for the control signal and a data region for user data, wherein different frequency bands within the control region are allocated to different user equipments, and transmitting the subframe in uplink direction. A control signal can be robustly transmitted under variance of channel condition.
1. In a wireless communication system, a method of transmitting a signal from a user equipment to a base station, the method comprising:
mapping, at the user equipment, the control signal to a cycle shifted sequence;
performing a Discrete Fourier Transform (DFT) on user data;
performing an Inverse Fast Fourier Transform (IFFT) on the mapped control signal, whereby generating a transformed control signal;
performing the IFFT on the DFT-spread user data, whereby generating transformed user data; and
transmitting at least one of the transformed control signal and the transformed user data in a subframe, the subframe comprising a control region and a data region in frequency domain, and a first slot and a second slot in time domain,
wherein a first portion of the control signal is transmitted at a first frequency in the first slot of the control region and a second portion of the control signal is transmitted at a second frequency in the second slot of the control region, and
wherein the user data is transmitted in the data region.
2. The method of claim 1 , wherein the control region occupies an upper and a lower portion of a subframe bandwidth and the data region occupies a portion of the subframe bandwidth between the upper and lower portions.
3. The method of claim 2 , wherein the first frequency used for transmitting the first portion of the control signal in the first time slot of the control region and the second frequency used for transmitting the second portion of the control signal in the second time slot of the control region are at least separated by the frequencies in the data region.
4. The method of claim 1 , wherein each of the first and second slots comprises a plurality of single carrier-frequency division multiple access (SC-FDMA) symbols.
5. The method of claim 4 , wherein at least one SC-FDMA symbol of the plurality of the SC-FDMA symbol in the control region is allocated to a reference signal and the remaining SC-FDMA symbols of the plurality of the SC-FDMA symbol in the control region are allocated to the control signal.
6. The method of claim 1 , wherein the control signal is an acknowledgement (ACK)/negative-acknowledgement (NACK) signal or a channel quality indicator (CQI).
7. The method of claim 1 , wherein the transformed control signal is transmitted in a first subframe and the transformed user data is transmitted in a second subframe.
8. The method of claim 1 , wherein the transformed control signal and the transformed user data are transmitted in same subframe.
9. In a wireless communications system, a user equipment comprising:
a data processing unit configured to map a control signal to a cycle shifted sequence and generate user data by encoding information bits;
a modulation unit configured to:
perform an Inverse Fast Fourier Transform (IFFT) on the mapped control signal, whereby generating a transformed control signal,
perform a Discrete Fourier Transform (DFT) on the user data, and
perform the IFFT on the DFT-spread user data, whereby generating transformed user data; and
a radio frequency unit and a transmit antenna configured to transmit at least one of the transformed control signal and the transformed user data in a subframe, the subframe comprising a control region and a data region in frequency domain, and a first slot and a second slot in time domain,
wherein a first portion of the control signal is transmitted at a first frequency in the first slot of the control region and a second portion of the control signal is transmitted at a second frequency in the second slot of the control region, and
wherein the user data is transmitted in the data region.
10. The user equipment of claim 9 , wherein the control region occupies an upper and a lower portion of a subframe bandwidth and the data region occupies a portion of the subframe bandwidth between the upper and lower portions.
11. The user equipment of claim 10 , wherein the first frequency used for transmitting the first portion of the control signal in the first time slot of the control region and the second frequency used for transmitting the second portion of the control signal in the second time slot of the control region are at least separated by the frequencies in the data region.
12. The user equipment of claim 9 , wherein each of the first and second slots comprises a plurality of single carrier-frequency division multiple access (SC-FDMA) symbols.
13. The user equipment of claim 12 , wherein at least one SC-FDMA symbol of the plurality of the SC-FDMA symbol in the control region is allocated to a reference signal and the remaining SC-FDMA symbols of the plurality of the SC-FDMA symbol in the control region are allocated to the control signal.
14. The user equipment of claim 9 , wherein the control signal is an acknowledgement (ACK)/negative-acknowledgement (NACK) signal or a channel quality indicator (CQI).
15. The user equipment of claim 9 , wherein the transformed control signal is transmitted in a first subframe and the transformed user data is transmitted in a second subframe.
16. The user equipment of claim 9 , wherein the transformed control signal and the transformed user data are transmitted in same subframe.