H04L27/264

TRELLIS CODED DFTS-OFDM
20240178937 · 2024-05-30 ·

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a transmitter. The transmitter receives a plurality of input bits. The transmitter encodes the plurality of input bits using a Trellis code to generate a plurality of output symbols. The Trellis code is configured to confine amplitude fluctuations between consecutive output symbols. The transmitter pulse shapes the output symbols in a frequency domain. The transmitter maps the pulse shaped symbols onto a plurality of subcarriers. The transmitter generates a time domain waveform based on the mapped symbols. The transmitter transmits the time domain waveform.

GENERALISED FFT-IFFT STRUCTURE BASED FREQUENCY DIVISION MULTIPLEXING TRANSCEIVER
20190190634 · 2019-06-20 ·

A generalized frequency division multiplexing (GFDM) transceiver system includes a low complex GFDM transmitter with multiple sub-carriers and timeslots having IFFT based modulator for modulating data corresponding to a particular timeslot and different sub-carriers to corresponding sub-carrier frequencies and thereby generating transmittable GFDM data signal, multipath frequency selective fading GFDM channel having uncorrelated channel coefficients corresponding to different paths for transmitting the modulated GFDM data signal and a low complex GFDM receiver configured to operate with said multipath frequency selective fading channel involving channel equalization followed by self-interference equalization to receive the transmitted modulated GFDM data signal and thereby de-modulate the GFDM data signal to obtain the data.

INFORMATION PROCESSING DEVICE, COMMUNICATION DEVICE, INFORMATION PROCESSING METHOD, COMMUNICATION METHOD, AND PROGRAM
20190173730 · 2019-06-06 · ·

[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.

OFDM modulator for block-filtered OFDM transmitter, related block-filtered OFDM transmitter and transceiver system

An OFDM modulator including a predistortion module configured to receive the N.sub.c consecutive data carriers and configured to compensate for distortion subsequently introduced by a polyphase filter bank connectable to the output of the OFDM modulator, a transformation module configured to apply a discrete inverse Fourier transform of constant size N.sub.IDFT independently of the numbering and transmission band used by the OFDM transmitter including the OFDM modulator, a filling module, the input of which is connected to the output of the predistortion module, and the output of which is connected to the input of the transformation module, and configured to insert (N.sub.IDFT?N.sub.c) null carriers in succession to the N.sub.c consecutive data carriers independently of the parity of the index i associated with the OFDM modulator.

Frame structure for filter bank multi-carrier (FBMC) waveforms

A unified frame structure for filter bank multi-carrier (FBMC) and orthogonal frequency division multiplexed (OFDM) waveforms may allow FBMC and OFDM frames to be communicated over a common channel without significant inter-frame gaps. The unified frame structure may set an FBMC frame duration to an integer multiple of an OFDM frame element duration to enable alignment of FBMC frames and OFDM frames in the time domain. The unified frame structure may also map control channels in the FBMC and OFDM frames to common resource locations so that the respective control channels are aligned in the time and/or frequency domains. The unified frame structure may also share synchronization channels between FBMC and OFDM frames. Additionally, overhead in an FBMC time division duplexed (TDD) communications channel can be reduced by overlapping time windows appended to FBMC blocks.

Adaptive Excision of Co-Channel Interference Using Network Self-Coherence Features
20190140872 · 2019-05-09 ·

An apparatus and digital signal processing means are disclosed for excision of co-channel interference from signals received in crowded or hostile environments using spatial/polarization diverse arrays, which reliably and rapidly identifies communication signals with transmitted features that are self-coherent over known framing intervals due to known attributes of the communication network, and exploits those features to develop diversity combining weights that substantively excise that co-channel interference from those communication signals, based on differing diversity signature, timing offset, and carrier offset between the network signals and the co-channel interferes. In one embodiment, the co-channel interference excision is performed in an appliqu? that can be implemented without coordination with a network transceiver.

System and Method for an Adaptive Frame Structure with Filtered OFDM
20190123872 · 2019-04-25 ·

Different filtered-orthogonal frequency division multiplexing (f-OFDM) frame formats may be used to achieve the spectrum flexibility. F-OFDM waveforms are generated by applying a pulse shaping digital filter to an orthogonal frequency division multiplexed (OFDM) signal. Different frame formats may be used to carry different traffic types as well as to adapt to characteristics of the channel, transmitter, receiver, or serving cell. The different frame formats may utilize different sub-carrier (SC) spacings and/or cyclic prefix (CP) lengths. In some embodiments, the different frame formats also utilize different symbol durations and/or transmission time interval (TTI) lengths.

APPARATUS AND METHOD

An apparatus including: a communication unit configured to perform radio communication; and a control unit configured to perform control such that control information regarding a filter length of a filter for limiting a width of a guard band in a frequency band to be used in the radio communication is transmitted to an external apparatus through the radio communication. The filter length is determined in accordance with at least one of a frequency resource and a time resource for the radio communication. The apparatus enables a filter improving frequency use efficiency.

System and method for an adaptive frame structure with filtered OFDM

Different filtered-orthogonal frequency division multiplexing (f-OFDM) frame formats may be used to achieve the spectrum flexibility. F-OFDM waveforms are generated by applying a pulse shaping digital filter to an orthogonal frequency division multiplexed (OFDM) signal. Different frame formats may be used to carry different traffic types as well as to adapt to characteristics of the channel, transmitter, receiver, or serving cell. The different frame formats may utilize different sub-carrier (SC) spacings and/or cyclic prefix (CP) lengths. In some embodiments, the different frame formats also utilize different symbol durations and/or transmission time interval (TTI) lengths.

ADAPTIVE EXCISION OF CO-CHANNEL INTERFERENCE USING NETWORK SELF-COHERENCE FEATURES
20240283682 · 2024-08-22 ·

An apparatus and digital signal processing means are disclosed for excision of co-channel interference from signals received in crowded or hostile environments using spatial/polarization diverse arrays, which reliably and rapidly identifies communication signals with transmitted features that are self-coherent over known framing intervals due to known attributes of the communication network, and exploits those features to develop diversity combining weights that substantively excise that cochannel interference from those communication signals, based on differing diversity signature, timing offset, and carrier offset between the network signals and the co-channel interferers. Co-channel interference excision may be performed in an appliqu? that can be implemented without coordination with a network transceiver.