In the present invention, regarding a narrowband used in a subframe for transmitting uplink data, if a switch is made from a first narrowband used in a first subframe to a second narrowband that is different from the first narrowband, with respect to a second subframe continuing to the first subframe, a final one symbol of the first subframe and an initial one symbol of the second subframe are punctured and set as a retuning time to transmit the uplink data in the first narrowband and the second narrowband.

An apparatus generating a packet of signals, a number of preamble signals of a preamble portion for each of a number of radio transmission units, and a number of data signals of a data portion, wherein a phase rotation in frequency domain is equal to a time shift in time domain is applied to each symbol of the number of preamble signals separately, the same phase rotation is applied to each symbol separately, the amount of the phase rotation is different for each preamble signal and each data signal, the amount of the phase rotation of one of the number of data signals and one of the number of preamble signals is both zero, and the amount of the phase rotation is equal between one of the preamble signals and one of the data signals for the same radio transmission unit.

A radio communication apparatus includes spreading circuitry that spreads a response signal using a first set of orthogonal sequences to produce a spread response signal. Each orthogonal sequence in the first set has a first length. The spreading circuitry also spreads a reference signal using a second set of orthogonal sequences to produce a spread reference signal. Each orthogonal sequence in the second set has a second length that is shorter than the first length. A radio transmitter transmits the spread response signal and the spread reference signal.

A radio communication apparatus includes spreading circuitry that spreads a response signal using a first set of orthogonal sequences to produce a spread response signal. Each orthogonal sequence in the first set has a first length. The spreading circuitry also spreads a reference signal using a second set of orthogonal sequences to produce a spread reference signal. Each orthogonal sequence in the second set has a second length that is shorter than the first length. A radio transmitter transmits the spread response signal and the spread reference signal.

When a plurality of terminals share the same resources in a wireless communication system, and when control information such as acknowledgement/negative acknowledgement (ACK/NAK) information or scheduling information is transmitted, a method of efficiently performing code division multiplexing (CDM) is required to distinguish the plurality of terminals. In particular, it is necessary to develop a method by which a code sequence of CDM can be selected and used according to each cell condition. Provided is a method of forming a signal in a wireless communication system in which a plurality of terminals commonly share frequency and time resources. The method includes the operations of receiving condition information in a cell; selecting one of a plurality of time domain orthogonal sequences having different lengths, according to the condition information; and allocating the selected time domain orthogonal sequence to a control signal symbol block.

When a plurality of terminals share the same resources in a wireless communication system, and when control information such as acknowledgement/negative acknowledgement (ACK/NAK) information or scheduling information is transmitted, a method of efficiently performing code division multiplexing (CDM) is required to distinguish the plurality of terminals. In particular, it is necessary to develop a method by which a code sequence of CDM can be selected and used according to each cell condition. Provided is a method of forming a signal in a wireless communication system in which a plurality of terminals commonly share frequency and time resources. The method includes the operations of receiving condition information in a cell; selecting one of a plurality of time domain orthogonal sequences having different lengths, according to the condition information; and allocating the selected time domain orthogonal sequence to a control signal symbol block.

A method by which a terminal estimates a channel in a wireless access system can comprises the steps of: receiving mapping information on a port and a layer of a data demodulation reference signal (DMRS); receiving change information on whether the port of the DMRS has been changed; and determining a change in port information on the basis of an indicator and estimating a channel of the DMRS.

A method by which a terminal estimates a channel in a wireless access system can comprises the steps of: receiving mapping information on a port and a layer of a data demodulation reference signal (DMRS); receiving change information on whether the port of the DMRS has been changed; and determining a change in port information on the basis of an indicator and estimating a channel of the DMRS.

Provided is an anti-interference method and system. The anti-interference method includes: setting an orthogonal code division sequence according to a subcarrier position in a frequency domain of resource elements (REs) of a data channel in at least one sub-frame; and configuring transmitting frequency domain symbols of the REs by using the orthogonal code division sequence corresponding to the subcarrier position of the REs.

In future radio communication systems, an uplink control channel will be transmitted properly. A user terminal has a receiving section that receives frequency hopping information, which indicates whether frequency hopping for an uplink control channel is enabled or not, and a control section that applies at least one of a spreading factor for a time-domain orthogonal cover code, a configuration of a demodulation reference code and a base sequence, to the uplink control channel, based on the frequency hopping information.