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.

System and methods enabling radio communications that are operating in noisy environments using OFDM (Orthogonal Frequency Division Multiplexing) are disclosed. A spread OFDM transmitter that generates OFDM symbols that may include multiple copies of IFFT symbols is disclosed. A spread OFDM receiver is disclosed for receiving the spread OFDM symbols. Other methods for symbol detection, frequency offset correction, and equalization are disclosed.

Embodiments herein describe an FFT that can bypass one or more stages when processing smaller frames. For example, when all the stages in the FFT are active, the FFT can process up to a maximum supported point size. However, the particular application may only every send smaller sized frames to the FFT. Instead of unnecessarily passing these frames through the beginning stages of the FFT (which adds latency and consumes power), the embodiments herein can bypass the unneeded stages which reduces the maximum point size the FFT can process but saves power and reduces latency. For example, the FFT can have selection circuitry (e.g., multiplexers) disposed between each stage that permits the input data to either bypass the previous stage(s) or the subsequent stage(s), depending on the architecture of the FFT. The bypassed stages can then be deactivated to conserve power.

Methods and systems for modulating and demodulating data in systems. Bits can be converted into complex-valued symbols. An Inverse Fast Fourier Transform (FFT) can be applied to the complex-valued symbols that represent the bit groups. An FFT time window can be replaced with a time window and a frequency window. A signal comprising the time window and the frequency window can be transmitted. The signal can be converted into a complex-valued symbol. The complex-valued symbols can be converted into bits.

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.

Provided is a communication system that can sustain a reduction in delay in FFT/IFFT processing by code blocking user data, even in a case where the functions of upper layers such as a MAC scheduler and the function of the radio physical layer are implemented separately. In a radio base station (communication system) including a central aggregation device 210 and a remote device 220, the central aggregation device 210 transmits code blocks in a number necessary for generating an OFDM symbol as a piece of data to the remote device 220, the code blocks being produced by dividing user data into units of encoding processing.

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 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.