A method of encoding data includes identifying multiple complex number pairs of a data vector and generating a transformed data vector by applying a non-linear transformation to each complex number pair from the multiple complex number pairs. The non-linear transformation includes modifying a phase of a first complex number from each complex number pair. The phase modification is based on a value associated with a second complex number from each complex number pair. A signal representing the transformed data vector is sent to multiple transmitters for transmission to multiple receivers. A signal representing the non-linear transformation is sent to a compute device for transmission of the non-linear transformation to the multiple receivers prior to transmission of the signal representing the transformed data vector from the multiple transmitters to the multiple receivers, for recovery of the data vector at the multiple receivers.

The apparatus may be a base station. The apparatus processes a plurality of synchronization signals by performing time-division multiplexing (TDM) of at least one of a plurality of first synchronization signals of different types and at least one of the plurality of second synchronization signals of different types, the plurality of synchronization signals including the plurality of first synchronization signals and the plurality of second synchronization signals. The apparatus transmits the processed synchronization signals to a user equipment (UE).

A user equipment (UE) receives a plurality of synchronization signals, the plurality of synchronization signals including a plurality of first synchronization signals of different types and a plurality of second synchronization signals of different types. Reception of the plurality of synchronization signals comprises: reception of a first transmission by receiving a first group of the plurality of synchronization signals; and reception of one or more repeat transmissions of the first transmission, wherein each of the one or more repeat transmissions of the first transmission includes a repetition of the first transmission, wherein the first transmission and the one or more repeat transmissions of the first transmission are received within a first synchronization subframe. The UE demultiplexes the plurality of synchronization signals by performing time-division demultiplexing of at least one of the plurality of first synchronization signals and at least one of the plurality of second synchronization signals.

A communication apparatus includes a receiver and a decoder. The receiver includes a plurality of antenna elements and, in operation, receives from a base station apparatus a modulated signal mapped to one of a plurality of subframes defined in a frame corresponding to a communicable range to which the communication apparatus belongs. The plurality of subframes are defined by time-division, frequency-division, or time-and-frequency division of the frame. A maximum number of modulated signals that can be simultaneously transmitted in a subframe from the base station apparatus varies depending on the communicable range. The decoder, in operation, decodes the received modulated signal.

Methods, systems, and devices for wireless communications are described that support noise tracking within transmission time intervals (TTIs) in wireless communications. A transmitting user equipment (UE) in direct communications with a receiving UE may transmit one or more reference signals that allow the receiving UE to estimate noise during different portions of a TTI and compensate for varying noise levels within the TTI. The transmitting UE may identify different sets of symbols within the TTI that are expected to have different noise levels, and may transmit one or more reference signals that allow for noise estimation at the receiving UE for each of the different sets of symbols.

A terminal apparatus includes circuitry and a transmitter. The circuitry, in operation, generates a reference signal using a cyclic shift value and an orthogonal sequence, which are associated with each other. The orthogonal sequence is one of two orthogonal sequences corresponding to a first orthogonal sequence [1, 1] and a second orthogonal sequence [1, 1]. The cyclic shift value is one of 12 cyclic shift values ranging from 0 to 11. The transmitter, in operation, transmits the reference signal multiplexed with a data signal. Two of the cyclic shift values having a difference of 6 are respectively associated with the two orthogonal sequences.

The disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). The present disclosure relates to a 5.sup.th generation (5G) or pre-5G communication system for supporting a higher data transmission rate beyond a 4th generation (4G) communication system such as long term evolution (LTE). A method for operating a base station in a wireless communication system, according to the present disclosure, comprises determining the window configuration to be applied to a transmission signal based on channel-related information of at least one UE; and transmitting control information comprising the window configuration to the at least one UE, wherein the window configuration comprises a length of each window to be applied to each of at least one subband of a frequency band allocated to the transmission signal.

A base station serving as a transmission apparatus includes a plurality of transmission antennas capable of forming beams directed to a plurality of terminals, which are reception apparatus, and a precoder configured to perform outer precoding on transmission signals transmitted from the plurality of transmission antennas. The plurality of terminals include at least one first reception apparatus, which are transmission destinations of the transmission signals, and second reception apparatus, which are reception apparatus other than the first reception apparatus. The precoder performs outer precoding on the transmission signals transmitted from the plurality of transmission antennas so that received power in the second reception apparatus among the plurality of reception apparatus is equal to or less than a threshold.

A communication system includes a repetitive orthogonal frequency-division multiplexing (ROFDM)transmitter communicating with an ROFDM receiver. The ROFDM transmitter includes an ROFDM modulator, which includes a K-point Fast Fourier Transform receiving a block of time-domain data symbols and generating an initial orthogonal frequency-division multiplexing symbol. The initial orthogonal frequency-division multiplexing symbol is based on a block of frequency-domain data symbols corresponding to the block of time-domain data symbols. The initial orthogonal frequency-division multiplexing symbol includes an ending part. The ROFDM modulator includes an orthogonal frequency-division multiplexing symbol repeater generating a repetitive orthogonal frequency-division multiplexing symbol by repeatedly reproducing the initial orthogonal frequency-division multiplexing symbol. The modulator includes a cyclic prefix adder pretending a cyclic prefix to the repetitive orthogonal frequency-division multiplexing symbol to generate a baseband transmitted signal. The cyclic prefix includes the ending part of the initial orthogonal frequency-division multiplexing symbol. The ROFDM receiver includes an ROFDM demodulator.

A method and apparatus for generating and utilizing spreading sequence codebooks for a symbol-level sequence spreading is disclosed. In one embodiment, a method performed by a wireless communication device, comprising: receiving a first number from a wireless communication node; selecting a first spreading sequence codebook from at least one spreading sequence codebook; selecting a first spreading sequence from the first spreading sequence codebook according to the first number; and spreading data symbols according to the first spreading sequence, wherein the at least one spreading sequence codebook each comprises a plurality of spreading sequences configured based on one entry of a first sequence set after cyclic shifting operation, wherein the first sequence set before cyclic shifting operation is configured based on a second sequence set.