Method for allocating phich and generating reference signal in system using single-user MIMO based on multiple codewords when transmitting uplink
The present invention relates to a method for generating an uplink reference signal in a system supporting plural uplink-access transmission modes. The method comprises: a step for transmitting the reference signal configuration information about the configuration of a reference signal from a base station to a user device through an uplink grant PDCCH (Physical Downlink Control Channel), and a step for receiving from the user device a sub-frame including the reference signal that is generated based on the reference signal configuration information. The reference signal configuration information is prepared for plural uplink access transmission modes and includes a cyclic shift value for the sequence of the reference signal. The reference signal is supposed to be transmitted to an uplink, and the user device is set up to be operated in the uplink-access transmission mode that corresponding to the reference signal configuration information.
1. A method of generating an uplink reference signal in a Single-User Multiple Input Multiple Output (SU-MIMO) system for transmitting one or more codewords in uplink, the method comprising:
transmitting, at a base station, reference signal configuration information indicating the configuration of reference signals to be transmitted in uplink to a user equipment through a uplink grant Physical Downlink Control Channel (PDCCH), wherein the user equipment is set to operate according to an uplink access mode corresponding to the information; and
receiving a subframe including the reference signals generated based on the reference signal configuration information from the user equipment,
wherein the reference signal configuration information includes cyclic shift values of sequences of the reference signals,
wherein the reference signal configuration information includes information about cyclic shifts of N (N≦M) reference signals among all M reference signals to be transmitted in uplink, and the information includes cyclic shift index of a reference signal used as a criterion among the N reference signals and offset information for determining cyclic shift indexes of remaining N−1 reference signals.
2. The method according to claim 1 , wherein the reference signal configuration information includes cyclic shift indexes of N (N≦M) reference signals among all M reference signals to be transmitted in uplink.
3. The method according to claim 2 , wherein the N reference signals are Constant Amplitude Zero Autocorrelaton (CAZAC) reference signals.
4. The method according to claim 2 , wherein the N reference signals of the M reference signals are inserted at predetermined symbol positions of a time domain and are subjected to a Discrete Fourier Transform (DFT) process.
5. The method according to claim 2 , wherein the N reference signals of the M reference signals are directly mapped to sample points corresponding to an allocated frequency transmission band at an input end of Inverse Discrete Fourier Transform (IDFT) or Inverse Fast Fourier Transform (IFFT).
6. The method according to claim 1 , wherein M is determined according to a number of physical transmission antennas, physical transmission antennas or transmission layers of a subframe configured in the user equipment.