45 results about "Planisphere" patented technology

The invention discloses a wireless communication system with full diversity and a full code rate. Planisphere matching is performed on input binary digit signals on a transmitting terminal. Uniform encoding is performed on modulated plural form analog signals in a Jafarkhani coding mode. Uniform encoded data are inversely converted to composite form analog signals through Fourier transform to be output. Signals of different transmitting sets in transmitting antennas are separated through the Fourier transform on a receiving terminal, and orthogonal decoding is performed. According to the wireless communication system, a system with more than four transmitting antennas achieves the full diversity and the full code rate on the transmitting terminal and the receiving terminal respectively, and therefore properties of the whole system are improved. The wireless communication system can also use an orthogonal decoding mode, and the complexity of decoding is reduced.

The invention discloses a rate adaptation method based on rateless codes and high-order QAM adaptive demodulation. A fixed modulation and coding scheme is adopted for a transmitting terminal, multiple demodulation modes are adopted for a receiving terminal, and different numbers of bits are demodulated from a received symbol. The decoding complexity constraint and the channel utilization rate are comprehensively considered, the corresponding demodulation mode and the decoding codeword length of the rateless error correcting codes are selected according to the channel quality, and rate adaptive adjustment is achieved. In the method, the modulation order is not limited, and the method is applicable to all square QAM planispheres. According to the scheme, efficient utilization of channels is considered, and meanwhile the decoding complexity is considered, so that the scheme is practical.

The invention discloses a wireless optical orthogonal multi-carrier communication method with a low peak to average power ratio. The wireless optical orthogonal multi-carrier communication method comprises the following steps that at a transmitting end, firstly, modulated frequency domain signals are converted into a semi-positive definite planning convex optimization problem by adopting a tone injection algorithm via a relaxation method, and solving is carried out through general convex optimization and randomized methods; secondly, the frequency domain signals are symmetrically mapped to subcarriers in a conjugate mode, and a cyclic prefix is added after reverse fast Fourier transformation; at last, time domain transmission signals are added into direct-current offset to drive a light-emitting diode to emit light. At a receiving end, photovoltaic conversion is achieved through a photodiode; signals are removed from the cyclic prefix and conjugate symmetry parts after amplification, filtering, analog-digital conversion and fast Fourier transformation; the signals are modulated to be recovered in an original planisphere; at last, receiving symbols are obtained through demodulation. According to the wireless optical orthogonal multi-carrier communication method, the peak to average power ratio of a wireless optical communication PFDM system can be effectively reduced, requirements of a power amplifier and an LED for linear degrees are reduced, non-linear distortion is reduced, and receiving performance is improved.