An Ethernet transceiver is disclosed. The Ethernet transceiver includes transmit circuitry having a forward error correction (FEC) encoder to encode data into FEC frames. A modulator modulates the FEC frames into symbols. A precoder equalizes the symbols and a transmitter transmits the equalized symbols over a reduced number of channels N.sub.S with respect to a baseline number of channels N.sub.0. For a reduced data rate B.sub.S with respect to a baseline data rate B.sub.0, the FEC frames are assembled by the FEC encoder to exhibit an expanded frame time FT.sub.S that is expanded from a baseline frame time FT.sub.0 by a factor of B.sub.0/B.sub.S. The modulator generates symbols that are transmitted by the transmit circuit at a symbol rate SR.sub.S that is reduced from a baseline symbol rate SR.sub.0 by a factor of (B.sub.0*N.sub.S)/(B.sub.S*N.sub.0).

An Ethernet transceiver is disclosed. The Ethernet transceiver includes transmit circuitry having a forward error correction (FEC) encoder to encode data into FEC frames. A modulator modulates the FEC frames into symbols. A precoder equalizes the symbols and a transmitter transmits the equalized symbols over a reduced number of channels N.sub.S with respect to a baseline number of channels N.sub.0. For a reduced data rate B.sub.S with respect to a baseline data rate B.sub.0, the FEC frames are assembled by the FEC encoder to exhibit an expanded frame time FT.sub.S that is expanded from a baseline frame time FT.sub.0 by a factor of B.sub.0/B.sub.S. The modulator generates symbols that are transmitted by the transmit circuit at a symbol rate SR.sub.S that is reduced from a baseline symbol rate SR.sub.0 by a factor of (B.sub.0*N.sub.S)/(B.sub.S*N.sub.0).

Orthogonal Time Frequency Space (OTFS) is a novel modulation scheme with significant benefits for 5G systems. The fundamental theory behind OTFS is presented in this paper as well as its benefits. We start with a mathematical description of the doubly fading delay-Doppler channel and develop a modulation that is tailored to this channel. We model the time varying delay-Doppler channel in the time-frequency domain and derive a new domain (the OTFS domain) where we show that the channel is transformed to a time invariant one and all symbols see the same SNR. We explore aspects of the modulation like delay and Doppler resolution, and address design and implementation issues like multiplexing multiple users and evaluating complexity. Finally we present some performance results where we demonstrate the superiority of OTFS.

Orthogonal Time Frequency Space (OTFS) is a novel modulation scheme with significant benefits for 5G systems. The fundamental theory behind OTFS is presented in this paper as well as its benefits. We start with a mathematical description of the doubly fading delay-Doppler channel and develop a modulation that is tailored to this channel. We model the time varying delay-Doppler channel in the time-frequency domain and derive a new domain (the OTFS domain) where we show that the channel is transformed to a time invariant one and all symbols see the same SNR. We explore aspects of the modulation like delay and Doppler resolution, and address design and implementation issues like multiplexing multiple users and evaluating complexity. Finally we present some performance results where we demonstrate the superiority of OTFS.

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.

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 disclosure discloses a method for constructing a TFDMA random self-organizing ad hoc network: the total spectrum bandwidth W is divided into N=W/Δf sub-channels, and Δf represents the bandwidth of one sub-channel. 24 hours a day is divided into U epochs, V time frames, S time slots, and E time chips. In an epoch of sub-channel bandwidth Δf, the last time slot is connected to the first time slot to form a time-frequency loop net. The N epoch-ring net corresponding to the N sub-channels are stacked together in a manner of time slot alignment to form a cylindrical web. A web is reused U times to cover the full spectrum bandwidth W and 24 hours a day, forming a time-frequency division multiple access self-organizing network.

The disclosure discloses a method for constructing a TFDMA random self-organizing ad hoc network: the total spectrum bandwidth W is divided into N=W/Δf sub-channels, and Δf represents the bandwidth of one sub-channel. 24 hours a day is divided into U epochs, V time frames, S time slots, and E time chips. In an epoch of sub-channel bandwidth Δf, the last time slot is connected to the first time slot to form a time-frequency loop net. The N epoch-ring net corresponding to the N sub-channels are stacked together in a manner of time slot alignment to form a cylindrical web. A web is reused U times to cover the full spectrum bandwidth W and 24 hours a day, forming a time-frequency division multiple access self-organizing network.

Wireless communications are described. A device may receive a message. The device may receive application data via a first cell group and a second cell group, and the device may transmit the application data to a communication device. The device may receive application data from a communication device, and the device may transmit the application data via a first cell group and a second cell group.

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.