A system includes a hardware accelerator configured to perform a two-dimensional (2D) fast Fourier transform (FFT) on an MN element array. The hardware accelerator has log.sub.2 MN pipeline stages including an initial group of log.sub.2 M stages and a final group of log.sub.2 N stages. Each stage includes a butterfly unit, a FIFO buffer coupled to the butterfly unit, and a multiplier coupled to the butterfly unit and to an associated twiddle factor table. The hardware accelerator also includes butterfly control logic to provide elements of the MN element array to the initial group of stages in an N direction of the array, and twiddle factor addressing logic to, for the twiddle factor tables of the initial group of stages, apply an indexed entry of the twiddle factor table to the associated multiplier. The indexed entry begins as a first entry and advances by N entries after every N cycles.

There is provided a method comprising: obtaining, by an apparatus, a first data block, a second data block and a third data block; generating a first signal, wherein a first part of the first signal is generated based on a data of the first data block, and wherein a second part of the first signal is generated based on a data of the second data block, the second part being subsequent in time domain compared with the first part; generating a second signal, wherein a first part of the second signal is generated based on a data of the third data block, and wherein a second part of the second signal is generated based on the data of the second data block, the second part being subsequent in time domain compared with the first part; and transmitting the first and second signals.

A method and apparatus for generating a preamble symbol in an Orthogonal Frequency Division Multiplexing (OFDM) system by generating a first main body sequence in a time domain by performing an inverse fast Fourier transform (IFFT) on a preset sequence in a frequency domain, generating a first postfix by copying samples in a preset section in the first main body sequence, generating a first prefix by copying samples in at least a portion of a section remaining by excluding the preset section from the first main body sequence, and generating a plurality of symbols, based on a combination of the first main body sequence, the first prefix, and the first postfix.

Disclosed is a method pilot-aided channel estimation in Orthogonal Frequency Division Multiplexing (OFDM) systems regardless of the frequency selectivity severity of the channel is proposed.

The present disclosure relates to a pre-5.sup.th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4.sup.th-Generation (4G) communication system such as Long Term Evolution (LTE). A method for operating a transmission device in a wireless communication system is provided. The method includes generating modulation symbols based on a modulation scheme, generating transformed data by applying a modified Fourier transform to the modulation symbols, generating a transmission signal based on the transformed data, and transmitting the transmission signal. The modified Fourier transform applies to each of the modulation symbols an amount of phase change that is shifted from an amount of reference phase change by a phase offset.

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.

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.

A transmitter includes: a frame generator configured to generate a frame including a frame starting symbol, at least one data symbol and a frame closing symbol; a pilot and reserved tone inserter configured to insert pilots and reserved tones in at least one of the frame starting symbol, the data symbol and the frame closing symbol such that positions of the reserved tones do not overlap positions of the pilots in the at least one of the frame starting symbol, the data symbol and the frame closing symbol; and a transmitter configured to transmit the frame in which the pilots and the reserved tones are inserted, wherein the reserved tones are not used to transmit data in the frame.

The present disclosure relates to a pre-5.sup.th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4.sup.th-Generation (4G) communication system such as Long Term Evolution (LTE). A method for operating a transmission device in a wireless communication system is provided. The method includes generating modulation symbols based on a modulation scheme, generating transformed data by applying a modified Fourier transform to the modulation symbols, generating a transmission signal based on the transformed data, and transmitting the transmission signal. The modified Fourier transform applies to each of the modulation symbols an amount of phase change that is shifted from an amount of reference phase change by a phase offset.

A transmitter includes: a frame generator configured to generate a frame including a frame starting symbol, at least one data symbol and a frame closing symbol; a pilot and reserved tone inserter configured to insert pilots and reserved tones in at least one of the frame starting symbol, the data symbol and the frame closing symbol such that positions of the reserved tones do not overlap positions of the pilots in the at least one of the frame starting symbol, the data symbol and the frame closing symbol; and a transmitter configured to transmit the frame in which the pilots and the reserved tones are inserted, wherein the reserved tones are not used to transmit data in the frame.