Patent classifications
H04L27/26532
METHOD AND APPARATUS FOR MODULATION IN COMMUNICATION SYSTEM
A method of a second communication node may comprise: obtaining a compensated first reception signal by performing channel estimation between a first communication node and a second communication node for a first transmission signal received from the first communication node; obtaining an offset-demodulated signal and a first demodulated bit sequence by performing offset-demodulation on the first reception signal; obtaining a frequency-domain signal by performing time-to-frequency domain transform on the offset-demodulated signal; obtaining a complex signal sequence by performing subcarrier deallocation on the frequency-domain signal; obtaining a second demodulated bit sequence by performing QAM demodulation on the complex signal sequence according to the first demodulated bit sequence; and obtaining a final demodulated bit sequence by performing reassembly on the first demodulated bit sequence and the second demodulated bit sequence.
Systems and Methods for Communicating by Modulating Data on Zeros
Systems and methods for transmitting data using various Modulation on Zeros schemes are described. In many embodiments, a communication system is utilized that includes a transmitter having a modulator that modulates a plurality of information bits to encode the bits in the zeros of the z-transform of a discrete-time baseband signal. In addition, the communication system includes a receiver having a decoder configured to decode a plurality of bits of information from the samples of a received signal by: determining a plurality of zeros of a z-transform of a received discrete-time baseband signal based upon samples from a received continuous-time signal, identifying zeros that encode the plurality of information bits, and outputting a plurality of decoded information bits based upon the identified zeros.
Iterative decoding of orthogonal time frequency space waveforms in the delay-doppler domain
Methods, systems and devices for wireless communication are described. One method includes obtaining a two-dimensional delay-Doppler representation of a received wireless signal that is received over a wireless channel, determining an estimated channel response of the wireless channel from a portion of the delay-Doppler grid corresponding to a channel estimation portion, performing, using the estimated channel response, channel equalization in the delay-Doppler domain, generating, based on the channel equalization, a posteriori probability estimates of data symbols in the received wireless signal, wherein the a posteriori probability estimates are generated based on a priori feedback that is generated using an iterative process and further processing the a posteriori probability estimates of data symbols to recover information bits from the received wireless signal.
Modulation and equalization in an orthonormal time-shifting communications system
A method for modulating data for transmission within a communication system. The method includes establishing a time-frequency shifting matrix of dimension NN, wherein N is greater than one. The method further includes combining the time-frequency shifting matrix with a data frame to provide an intermediate data frame. A transformed data matrix is provided by permuting elements of the intermediate data frame. A modulated signal is generated in accordance with elements of the transformed data matrix.
ITERATIVE DECODING OF ORTHOGONAL TIME FREQUENCY SPACE WAVEFORMS IN THE DELAY-DOPPLER DOMAIN
Methods, systems and devices for wireless communication are described. One method includes obtaining a two-dimensional delay-Doppler representation of a received wireless signal that is received over a wireless channel, determining an estimated channel response of the wireless channel from a portion of the delay-Doppler grid corresponding to a channel estimation portion, performing, using the estimated channel response, channel equalization in the delay-Doppler domain, generating, based on the channel equalization, a posteriori probability estimates of data symbols in the received wireless signal, wherein the a posteriori probability estimates are generated based on a priori feedback that is generated using an iterative process and further processing the a posteriori probability estimates of data symbols to recover information bits from the received wireless signal.
TRANSMITTER AND RECEIVER FOR, AND METHOD OF, TRANSMITTING AND RECEIVING SYMBOLS OVER TIME VARYING CHANNELS WITH DOPPLER SPREAD
A communication frame for an OTFS transmission system includes first-type and second-type blocks. The first-type block includes pilot signals, guard signals, and data signals, the second-type block exclusively includes data signals. The pilot symbols, guard signals, and data symbols of the first-type block, and the data symbols of the second-type block, are arranged along the points of a grid in the delay-Doppler domain. In the communication frame, a first-type block is followed by a second-type block, and a second-type block is followed by a first-type block. In the first-type block at least one pilot symbol is surrounded on at least three sides by one or more guard symbols. Points of the grid of the first-type blocks in the delay-Doppler domain that are not occupied by pilot symbols or guard symbols are used for data symbols. The communication frame permits determining oscillator frequency offset and channel coefficients in a receiver.
TRANSMITTER AND RECEIVER FOR, AND METHOD OF, TRANSMITTING AND RECEIVING SYMBOLS OVER TIME VARYING CHANNELS WITH DOPPLER SPREAD
A communication frame for an OTFS transmission system includes first-type and second-type blocks. The first-type block includes pilot signals, guard signals, and data signals, the second-type block exclusively includes data signals. The pilot symbols, guard signals, and data symbols of the first-type block, and the data symbols of the second-type block, are arranged along the points of a grid in the delay-Doppler domain. In the communication frame, a first-type block is followed by a second-type block, and a second-type block is followed by a first-type block. In the first-type block at least one pilot symbol is surrounded on at least three sides by one or more guard symbols. Points of the grid of the first-type blocks in the delay-Doppler domain that are not occupied by pilot symbols or guard symbols are used for data symbols. The communication frame permits determining oscillator frequency offset and channel coefficients in a receiver.
OFDM-based method and device for spreading and transmitting compressed data
The present disclosure relates to a communication technique that merges IoT technology with a 5G communication system for supporting higher data transmission rates than 4G systems, and a system therefor. The present disclosure may be applied to intelligent services (for example, smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail business, security and safety-related services, etc.) on the basis of 5G communication technology and IoT-related technology. A method for a transmitter of a communication system according to the present disclosure is characterized by: transmitting configuration information for signal transmission to a receiver, checking resources for the signal transmission; transmitting scheduling information indicating the resources to the receiver; converting a transmission signal to a compressed signal so as to correspond to the configuration information; spreading the compressed signal to multiple dimensions; mapping a portion of the spread compressed signal to the resources corresponding to the scheduling information; converting the spread compressed signal to generate an orthogonal frequency-division multiplexing (OFDM) signal; and transmitting the generated OFDM signal to the receiver.
Windowing for OTFS-based communication systems under fractional delay-doppler and adjacent channel interference
Disclosed is a windowing method for OTFS-based wireless signals to mitigate interference due to fractional delay and Doppler cases and to control out-of-band emission. The method provides for suitable windowing mechanisms for the multicarrier orthogonal time frequency space (OTFS) scheme in order to manage out-of-band emission and interference due to the limited time and frequency resolution of the OTFS frame.
Transmitter and receiver for, and method of, transmitting and receiving symbols over time varying channels with Doppler spread
A communication frame for an OTFS transmission system includes first-type and second-type blocks. The first-type block includes pilot signals, guard signals, and data signals, the second-type block exclusively includes data signals. The pilot symbols, guard signals, and data symbols of the first-type block, and the data symbols of the second-type block, are arranged along the points of a grid in the delay-Doppler domain. In the communication frame, a first-type block is followed by a second-type block, and a second-type block is followed by a first-type block. In the first-type block at least one pilot symbol is surrounded on at least three sides by one or more guard symbols. Points of the grid of the first-type blocks in the delay-Doppler domain that are not occupied by pilot symbols or guard symbols are used for data symbols. The communication frame permits determining oscillator frequency offset and channel coefficients in a receiver.