Disclosed are a method and a device for transmitting uplink control information (UCI) by a terminal in a wireless communication system. The UCI transmission method comprises the steps of: generating an encoding information bit stream by performing channel coding for a UCI bit stream; generating complex modulation symbols by performing modulation for the generated encoding information bit stream; spreading the complex modulation symbols in block-wise on the basis of an orthogonal sequence; and transmitting the spread complex modulation symbols to a base station. The encoding information bit stream is generated by a channel coding for circularly repeating the UCI bit stream.

A response signal in each subframe is multiplied by a corresponding one of components forming one of a plurality of first sequences orthogonal to each other. The response signal is also multiplied by a second sequence defined by one of a plurality of cyclic shift indexes and one of a plurality of third sequences orthogonal to each other. Among a plurality of resources, a resource associated with one of at least two first sequences of the plurality of first sequences is different from a resource associated with another one of the at least two first sequences. Each of the plurality of resources is constituted by one of the plurality of cyclic shift indexes and one of the plurality of third sequences.

A receiver receives signals and noise over a frequency spectrum of a desired received signal. The desired received signal is spread using code division multiple access. The received signals and noise are demodulated to produce a demodulated signal. The demodulated signal is despread using a code uncorrelated with a code associated with the desired received signal. A power level of the despread demodulated signal is measured as an estimate of the noise level of the frequency spectrum.

A method and apparatus for multiplexing reference signals in a predetermined number of Code Division Multiplexing (CDM) groups to balance power across Orthogonal Frequency Division Multiplexing (OFDM) symbols are disclosed. In a wireless communication system, orthogonal sequences used for spreading the reference signals are allocated such that the order of orthogonal sequences allocated to a subcarrier of one CDM group has a predetermined offset with respect to the order of orthogonal sequences allocated to a subcarrier of another CDM group, adjacent to the subcarrier of the one CDM group.

A wireless communication apparatus and method minimizes degradation in a separation characteristic of a code-multiplexed response signal using two-dimensional processing. One of plural cyclic shift values defines a reference signal sequence that is spread with an orthogonal sequence associated with one of the plural cyclic shift values. This two-dimensional processing compensates for interference affecting the reference signal.

A terminal apparatus is disclosed wherein even in a case of applying SU-MIMO and MU-MIMO at the same time, the inter-sequence interference in a plurality of pilot signals used by the same terminal can be suppressed to a low value, while the inter-sequence interference in pilot signal between terminals can be reduced. In this terminal apparatus: a pilot information deciding unit decides, based on allocation control information, Walsh sequences of the respective ones of first and second stream groups at least one of which includes a plurality of streams; and a pilot signal generating unit forms a transport signal by using the decided Walsh sequences to spread the streams included in the first and second stream groups. During this, Walsh sequences orthogonal to each other are established in the first and second stream groups, and users are allocated on a stream group-by-stream group basis.

A signal processing method is provided. The signal processing method includes: determining, by a first communication device, a first Walsh sequence based on first indication information; performing, by the first communication device, spectrum spreading on an original signal based on the first Walsh sequence to generate a first signal; and transmitting, by the first communication device, the first signal to a second communication device. The first communication device is a device that provides a radio frequency carrier source for the second communication device.

An optical communication method using deep learning in a code-division multiple access (CDMA) scheme may include obtaining an image of an optical signal from a light source and applying a first model trained to identify a location of the light source to detect the light source in the image. The method may also include detecting a preamble of an on-off keying (OOK) modulated signal from a pulse signal generated based on the identified light source using a second model trained to detect preambles in received signals, to decode the OOK modulated signal for a first user device by applying a first pseudo-random noise (PN) code. The method may further include determining a start position of an orthogonal frequency division multiplexing (OFDM) frame in an OFDM modulated signal from the pulse signal, to decode the OFDM modulated signal by applying a first Walsh code.

A method of a base station may comprise: mapping at least one port of the base station to each of a plurality of user equipments (UEs) to be overloaded; configuring overloading signatures for a code division multiplexing (CDM) scheme; mapping the overloading signatures with the plurality of UEs to be overloaded, respectively; transmitting a message including configuration information of the overloading signatures to the plurality of UEs; and transmitting, to the plurality of UEs, signals multiplexed by the CDM scheme using the overloading signatures.

Certain aspects of the present disclosure provide techniques for selecting a first orthogonal cover code (OCC) codeword from an OCC matrix for a transmission occurring during a first transmission time interval based on a first pseudo-random codeword allocator function, such as a first pseudo-random permutation matrix, corresponding to the first transmission time interval; and sending the transmission during the first transmission time interval using the first OCC codeword.