The present disclosure provides a multi-carrier time-division multiplexing (MC-TDMA) modulation and demodulation method and system. Before multi-carrier modulation is performed on an input symbol, an interleaving allocation and an FFT may be performed, a time domain symbol may be transformed into a frequency domain symbol signal to perform a MDFT treatment. A sending end may adopt an analyzing filter bank structure, and pre-filtering and an IFFT may be performed on a signal successively. A pre-filter may be positioned between an NM point FFT and an M point IFFT, a PAPR value of the system may be reduced using the symmetry of a coefficient of a filter, and a frequency domain symbol signal may be allocated to different sub-bands for multi-carrier modulation.

Performing wireless transmissions over a unified air interface that span portions of both the primary band and the complementary band may provide improved throughput and spectral efficiency in next generation networks. Wireless transmissions spanning both the licensed and unlicensed spectrum carry data in different frame formats over the respective primary and complementary bands. For example, frames communicated over the primary band may have a different channel structure (e.g., different size, placement, orientation, etc.) than frames communicated over the complementary band. Wireless transmissions spanning the licensed and unlicensed spectrum may also utilize different access schemes and/or waveforms over the respective primary and complementary bands. Embodiment unified air interfaces may be dynamically configurable via software defined radio (SDR) signaling instructions.

[Object] To realize IQ imbalance correction in a more preferable aspect. [Solution] An information processing device including: a calculation unit configured to calculate an error between predetermined reference coordinates on an IQ plane and a signal point of a received predetermined reference signal on a basis of a reception result of the reference signal on which phase modulation or quadrature amplitude modulation is implemented and mapping information of the reference signal; and a generation unit configured to generate correction data for correcting a deviation of a signal point of a received signal on a basis of a calculation result of the error.

Systems and methods are provided for channelizing. A first stage can provide a WOLA filter bank that can apply a single multiplier resource to perform window weighting for multiple WOLA filter banks. The first stage can remove mixer-based post FFT adjustment and provide equal functionality with a particular modification of tuning mixers at inputs of second stage FIR paths. The first stage can include a variable decimation, using a particular implementation of variable sample block size.

The present disclosure discloses a communication method and a communications apparatus. The method includes: determining, by a first communications device, a first subcarrier spacing corresponding to a first subband; and performing, by the first communications device, signal transmission on the first subband with a second communications device based on the first subcarrier spacing; or determining, by a first communications device, a second subcarrier spacing corresponding to a second subband; and performing, by the first communications device, signal transmission on the second subband with a second communications device based on the second subcarrier spacing. The first subcarrier spacing is different from the second subcarrier spacing, and both the first subcarrier spacing and the second subcarrier spacing are integral multiples of a basic frequency spacing; and both bandwidth of the first subband and bandwidth of the second subband are integral multiples of the basic frequency spacing.

A method and apparatus for performing pulse shaping using different windowing functions for different sub-bands of a transmission is disclosed. A method for use in a wireless transmit/receive unit (WTRU) may include the WTRU receiving data symbols. The WTRU may assign the data symbols to a plurality of subcarriers in different sub-bands and map the data symbols on each of the plurality of subcarriers in the different sub-bands to a plurality of corresponding subcarriers of an inverse fast Fourier transform (IFFT) block. The WTRU may take an IFFT of the block for each sub-band and pad an output of the IFFT block with a prefix and a postfix for each sub-band. The WTRU may apply a windowing function to an output of the padding for each sub-band and form a composite signal for transmission by adding an output of the windowing of each sub-band. The WTRU may transmit the signal.

Cyclic prefix based OFDM (CP-OFDM) signals can be filtered using a digital filter whose filter length exceeds the length of a cyclic prefix in CP-OFDM symbols of the signal. In one example, the duration of the filtered CP-OFDM symbol may be expressed by the following equation: M=N+L1, where M is the duration of the filtered CP-OFDM signal, N is a duration of the CP-OFDM signal, and L is the filter length of the digital filter. Digitally filtering the CP-OFDM signal may include convolving a filtering signal with the CP-OFDM signal. The digital filter may include a finite impulse response (FIR) filter or an infinite impulse response (IIR) filter. In some embodiments, a different digital filter may be applied to each sub-band of the CP-OFDM signal.

Disclosed are a roll-off period detection method, a symbol starting point detection method, a fractional frequency offset estimating method, and an OFDM downstream system using the same. A method of detecting a roll-off period in an OFDM downstream system according to an embodiment of the present disclosure may include: generating a temporary roll-off period by applying a windowing function to a signal having a preset length; and detecting a roll-off period based on any one of a cross correlation and a sum of differences between a detection target signal included in a range of two OFDM symbol signals based on a detection starting point, and the temporary roll-off period.

Highly efficient digital domain sub-band based receivers and transmitters.

Circularly pulse-shaped waveforms for communication systems are disclosed herein, including a single carrier modulation in which pulse-shaping is performed using a circular convolution by the transmitter for various modulation schemes. A transmitter, related method, and corresponding receiver are also disclosed for demodulation of the single carrier circularly pulse-shaped signal and data extraction.