3 results about "Single carrier modulation" patented technology

The application discloses a kind of adaptive QAM and OFDM bimodulus intracorporeal ultrasonic communication system and method based on channel estimation, belong to intracorporeal ultrasonic communication technical field, the transmitting end is configured with single carrier QAM modulation mode and multicarrier OFDM modulation mode, real-time evaluation intracorporeal ultrasonic channel quality in receiving end, according to the optimal modulation mode of evaluation result, according to the optimal modulation mode generation mode switching instruction, the mode switching instruction is sent to transmitting end, transmitting end according to the mode switching instruction seamlessly switches between single carrier QAM modulation mode and multicarrier OFDM modulation mode, so that transmitting end works in optimal modulation mode, the system and method can dynamically select optimal modulation mode according to intracorporeal channel real-time quality parameter, while ensuring that mode switching is reliably synchronized.

Receiver devices for single-carrier modulation are disclosed. In particular, the receiver devices of the present disclosure are able to deal with doubly selective channels (i.e., channels varying in time and frequency). The receiver devices are configured to determine channel state information (CSI) of a communication channel and a plurality of signature roots based on the CSI. Each signature root of the plurality of signature roots is a nonzero complex point, wherein the plurality of signature roots are uniformly distributed on a circumference of a circle in a complex plane. The receiver devices are further configured to construct a first Vandermonde matrix based on the plurality of signature roots, perform a demodulation of a single-carrier modulated signal, based on the first Vandermonde matrix, to obtain a demodulated signal, and obtain symbols based on performing an iterative procedure on the demodulated signal.