A terminal transmits and receives a slot configured with a plurality of symbols. The terminal sets a length of a cyclic prefix added to each symbol based on a degree of compression of each symbol in time domain.

Aspects of the present application provide methods and devices for time domain implementation of a single carrier waveform such as single carrier quadrature amplitude modulation (QAM) DFT-s-OFDM and single carrier Offset QAM (OQAM). A time domain implementation allows flexible symbol lengths, lower implementation complexity as a large IDFT operation is not required in the time domain and support for variable cyclic prefix (CP) length. An OQAM implementation utilizes a pre-processing step to convert a K complex QAM symbol sequence into a 2K OQAM symbol sequence and generates a sequence for transmission in the time domain as opposed to the frequency domain.

Aspects of the present application provide methods and devices for time domain implementation of a single carrier waveform such as single carrier quadrature amplitude modulation (QAM) DFT-s-OFDM and single carrier Offset QAM (OQAM). A time domain implementation allows flexible symbol lengths, lower implementation complexity as a large IDFT operation is not required in the time domain and support for variable cyclic prefix (CP) length. An OQAM implementation utilizes a pre-processing step to convert a K complex QAM symbol sequence into a 2K OQAM symbol sequence and generates a sequence for transmission in the time domain as opposed to the frequency domain.

Highly efficient digital domain sub-band based receivers and transmitters.

Highly efficient digital domain sub-band based receivers and transmitters.

Disclosed is a demodulation method to be used by an apparatus receiving a data packet transmitted in wired and wireless communications to recover data from a received signal. The apparatus receiving the data packet may recover or synchronize a symbol timing that is used to recover the data, and a demodulator included in the apparatus receiving the data packet may determine the symbol timing through different methods based on a length of a burst included in the data packet.

Highly efficient digital domain sub-band based receivers and transmitters.

Disclosed is a demodulation method to be used by an apparatus receiving a data packet transmitted in wired and wireless communications to recover data from a received signal. The apparatus receiving the data packet may recover or synchronize a symbol timing that is used to recover the data, and a demodulator included in the apparatus receiving the data packet may determine the symbol timing through different methods based on a length of a burst included in the data packet.

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 implementations allow increases in data rate provided by the Faster-Than-Nyquist multi-carrier signaling to he balanced against system conditions to maintain transmission error rates on channels within an acceptable range. If conditions such as channel traffic load, inter-system interference, intra-system interference, available transmission power, and/or available bandwidth change, the Faster-Than-Nyquist multi-carrier signaling acceleration factor used on system channels may be adjusted based on the changing conditions. If conditions change unfavorably, the acceleration factor may be increased to lower the data rate so that the error rate improves on the one or more channels. If conditions change favorably, the acceleration factor may be decreased to increase the data rate in the improved channel conditions. During system operation, channel conditions may be monitored, and the acceleration factor on the channels may be adjusted to provided higher or lower data rates according to any changes in the channel conditions.