Systems (400) and methods for removing dither introduced into a transmitted RF signal. The method comprising: receiving, by a receiver, the transmitted RF signal; converting, by the receiver, the transmitted RF signal into a discrete-time IF signal comprising a sequence of samples, where at least a first sample of said samples has a first sample duration different than a second sample duration of at least a second sample of said samples; and performing operations by a sub-sample dither removal device of the receiver to modify a sample timing of the discrete-time IF signal by decreasing or increasing the first sample duration of the first sample using a digital signal processing technique in a digital domain.

The disclosure refers to a synthesis filter bank, comprising: a transform module which is configured to receive a plurality of input signals, transform the plurality of input signals, and output a plurality of transformed signals, a plurality of filter modules, which are coupled to the transform module, and wherein each filter module of the plurality of filter modules is configured to receive two transformed signals from the transform module, process the two received transformed signals and output two processed signals, and a parallel-to-serial module which is coupled to the plurality of filter modules and which is configured to receive the processed signals from the plurality of filter modules, combine the received processed signals and output a combined signal. Furthermore, an analysis filter bank, a filter bank and methods for operating a synthesis filter bank and for operating an analysis filter bank are disclosed.

Data modulation for use in a multi-carrier system, a demodulation method, a frame generation method, and a node. A transmitter node performs an inverse fast Fourier transform (IFFT) on successive L symbols of frequency domain data, wherein an inverse of an adjacent subcarrier interval of the frequency domain data is T0, and L2. The transmitter node modulates, using a designated wave function, the successive L symbols of time domain data generated after the IFFT process, wherein an adjacent symbol interval of the L symbols after the modulation is T1, and T1>T0. A variable interval length of the designated wave function is NT1, where N is a real number exceeding or equal to 2 or 3. The application also provides the corresponding demodulation method, frame generation method, and node. The application can better inhibit out-of-band power leakage, and maintain compatibility to LTE. Furthermore, an increased demodulation performance is provided at a receiver end.

Provided is a data processing method and apparatus. The method includes: performing an inverse fast Fourier transform (IFFT) on data and processing the data with a preset function. The preset function is the product of a first function and a second function. The first function is a function in a time domain obtained by performing a Fourier transform on a root-raised cosine function in a frequency domain. The second function is in the time domain.

An apparatus that can make a success of demodulation on the reception side even if the restrictions on the resource setting are lifted. The apparatus includes: a processing unit configured to variably set at least any of a number of subcarriers or a number of subsymbols included in a unit resource including one or more subcarriers or one or more subsymbols, and set a filter coefficient that is applied in accordance with different rules which depend on whether the number of subsymbols included in the unit resource is an even number or an odd number.

How to apply an Alamouti like space-time coding (or transmit diversity) to a Filter Bank Multicarrier (FBMC) transmission using Offset QAM (OQAM). In FBMC, due to the orthogonality in the real domain only, an intrinsic interference results thereof for the imaginary component. Simply adapting the Alamouti scheme to FBMC OQAM is not obvious since the intrinsic interference terms are not equivalent at each antenna since it depends on the surrounding symbols. The application proposes to use a precoding symbol chosen to cancel out (zero) the intrinsic interference individually for each antenna, ie a code rate of (sending one data symbol requires two time units). A more elaborated embodiment proposes to choose the contiguous precoding symbols such that a virtual QAM Alamouti scheme is achieved, without rate loss.

An alternative method of data communications using orthogonal time frequency shifting (OTFS) wireless waveforms configured so as to transmit data in a manner that is relatively insensitive to communications channel distortions and frequency shifts. In contrast to prior methods taught by applicant, the present disclosure teaches an alternative modulation scheme that maps data symbols intended for data transmission onto a symplectic-like 2D Fourier transform which operates on a form of the original data symbols. This 2D Fourier transform in turn is passed through a filter bank of narrow band filters, and the output in turn used to modulate transmitted waveforms according to various time slices until the entire 2D Fourier transform has been transmitted. At the receiver, and inverse of this process can be used to both characterize the data channel and correct the received signals for channel distortions, thus receiving a clear form of the original data symbols.

The present disclosure relates to a 5G or pre-5G communication system for supporting a higher data transfer rate than a 4G communication system such as LTE. The present invention relates to channel estimation and equalization in a cellular environment on the basis of an FBMC transmission and reception technique. A communication method of a base station according to one embodiment of the present invention may comprise the steps of: determining a reference signal (RS) pattern building block of a plurality of cells according to filter information of the plurality of cells; determining an RS pattern of the plurality of cells by using the determined RS pattern building block and the size of a resource block (RB); and transmitting, to a terminal, information about the determined RS pattern. According to one embodiment of the present invention, it is possible to provide a method and an apparatus for mapping a reference signal in a multi-cell environment.

A method for synchronization of an emitter of FBMC system with a RACH channel. On the emitter, a pseudo-random sequence with an initial offset in relation to a reference sequence is inserted into the spectral band of the RACH channel. On the receiver, the sequence received on the RACH channel is estimated using a sliding FFT using a starting point and correlated with the reference sequence. The position of the starting point leading to the highest correlation peak is selected as well as the correlation position corresponding to this peak, with these two positions making it possible to determine the offset of the sequence received with the reference sequence. This offset is transmitted to the emitter and the latter deduces from it a delay to be compensated in the emission in order to synchronize with the receiver.

An FBMC transmission/reception system wherein a phase pre-compensation and an amplitude pre-compensation are done on a block of modulation symbols. The symbol block thus compensated is segmented into a number M of sub-blocks equal to the number of carriers of an FBMC modulator. The sub-blocks are divided into vectors with size N/2 and padded with isolation zeroes to form padded vectors with size N. Each of these padded M is processed by an IFFT to give time sequences to which cyclic prefixes and suffixes are added. The resulting cyclic sequences are then input to the M input channels of the FBMC modulator. The reception symbols can be recovered at the receiver by a simple FFT with size NM/2.