A signal processing circuit includes an encoding circuit and a subcarrier sorting circuit. The encoding circuit is arranged to encode an input data to generate multiple codewords corresponding to a symbol. The subcarrier sorting circuit is arranged to sequentially arrange multiple subcarriers into an array, wherein a size of the array is M*N, N is a number of columns, N is equal to a number of the multiple codewords corresponding to the symbol, M is a number of rows, and M is a number of the multiple subcarriers divided by N; and the multiple subcarriers are sequentially arranged into the array starting from a row of the array, and subcarriers comprised in each column of the array are arranged to transmit one of the multiple codewords.

A transmitter of an FBMC-MIMO system in which, for each FBMC-OQAM modulator associated with a transmission antenna, the symbols of a block to be transmitted are grouped in pairs, the input symbols in a pair being combined to output first and second combined symbols, the combined symbols being input to the FBMC-OQAM modulator. The invention also relates to a receiver including an FBMC-OQAM demodulator (410.sub.1, . . . ,410.sub.N.sub.R) and an ML detector (450.sub.k) from the observables obtained, for each reception antenna. The used ML detection allows for not being affected by intrinsic interference and obtaining a high degree of diversity without increasing the number of antennas.

A plurality of candidate transmission signals which are modulated according to a discrete Fourier transform (DFT)-spread filter-bank multi-carrier (FBMC)/offset quadrature amplitude modulation (OQAM) scheme and are capable of achieving a single carrier effect are generated. A candidate transmission signal having the smallest peak to average power ratio (PAPR) is selected and transmitted, so that a PAPR performance can be effectively improved.

A method is provided for modulating data symbols, outputting a multi-carrier signal, implementing: a mathematical transform, which transforms data symbols from the frequency domain to a time domain, outputting transformed symbols; and a polyphase filtering, which filters the transformed symbols, outputting the multi-carrier signal. The polyphase filtering uses an expansion factor taking account of a compression factor , the compression factor being a number between 0 and 1 such that the multi-carrier signal can be transmitted at a Faster-Than-Nyquist rate.

Disclosed is a 5G or pre-5G communication system to be provided for supporting a data transmission rate higher than that of a 4G communication system such as LTE. Particularly, the present invention relates to a communication device and method in a filter-bank based single carrier frequency division multiple access (FB based SC-FDMA) system and, particularly, to a communication device and method for lowering a peak to average power ratio (PAPR) in an uplink.

This invention discloses a multicarrier communication system that includes a transmitter equipment and a receiver equipment. According to a timing scheme, the transmitter equipment processes multiple original symbols for transmission on multiple subcarrier channels, and the receiver equipment processes and detects multiple received symbols from the multiple subcarrier channels. During a time frame of data transmission, the initial three of the original symbols for each of the subcarrier channels are three pilot symbols, forming a preamble. The three preambles of every consecutive three of the subcarrier channels form a preamble unit. All the pilot symbols of the preamble unit are expressed as a 33 matrix. When the center pilot symbol of the preamble unit is normalized to 1 or j (i.e., the imaginary unit), the matrix is

[00001]$\left[\begin{array}{ccc}-j& -j& -j\\ j& 1& -j\\ -j& j& -j\end{array}\right].Math..Math.\mathrm{or}.Math.\left[\begin{array}{ccc}1& 1& 1\\ -1& j& 1\\ 1& -1& 1\end{array}\right].$

A channel estimation method for the multicarrier communication system is also disclosed.

A method for transmitting multiple communications of different types, in particular sporadic (MTC) or cellular (broadband) communication including symbols to be transmitted, corresponding to communication services implementing a modulation having M subcarriers of the FBMC-OQAM or OFDM-OQAM type. The method uses linear frequency filtering of a sequence of length N including symbols having L coefficients that are parametrizable according to the communication, L, N, and M being natural numbers, so as to generate N+L1 symbols, reducing out-of-band spurious emissions. The method also uses, no matter what the communication is, a single frequency/time transform (IFFT) having a size M, where N<M. For sporadic communications (MTC) in a lower frequency band, the constraints on the out-of-band side-lobes are more stringent on the filter and FBMC modulation is thus better adapted.

A method and apparatus for orthogonal frequency division multiplexing (OFDM) modulation includes separating a frequency-domain sequence of complex numbers into a first portion and a second portion that is disjoint with the first portion, each of the first portion and the second portion including a respective half of the complex numbers of the frequency-domain sequence, and generating a time-domain sequence having a real in-phase component that is a function of the first portion only, and an imaginary quadrature-phase component that is a function of the second portion only.

Disclosed herein is a station (STA) device of a wireless LAN (WLAN) system. The STA device includes a radio frequency (RF) unit sending and receiving a radio signal and a processor controlling the RF unit. The processor may generate a physical protocol data unit (PPDU) including a physical preamble and a data field and send the PPDU using the RF unit.

A transmission method and an FBMC transmitter to transmit at least a first and a second block of symbols (X.sub.0, X.sub.1), each symbols block including a temporal sequence of L vectors with predetermined size N. It uses a first and a second FBMC modulation channel, each FBMC modulation channel being associated with an antenna. During a first use of the channel, the vectors of the first block and the vectors of the second block are input to the first and to the second FBMC modulation channels respectively, in the order of the temporal sequence. During a second use of the channel, the vectors of the first and second blocks are multiplied by a factor j.sup.L 1 respectively and (j.sup.L 1) input to the second and to the first FBMC modulation channels respectively, in the inverse order of the temporal sequence.