The present disclosure discloses a new coding scheme, which is constructed by superimposing together a pair of basic codes in a twisted manner. A SCL decoding algorithm is proposed for the TPST codes, which may be early terminated by a preset threshold on the empirical divergence functions (EDF) to trade off performance with decoding complexity. The SCL decoding of TPST is based on the efficient list decoding of the basic codes, where the correct candidate codeword in the decoding list is distinguished by employing a typicality-based statistical learning aided decoding algorithm. Lower bounds for the two layers of TPST are derived, which may be used to predict the decoding performance and to show the near-ML performance of the proposed SCL decoding algorithm. The construction of TPST codes may be generalised by allowing different basic codes for the two layers.

The disclosed systems, structures, and methods are directed to encoding and decoding information for transmission across a communication channel. The encoding method includes: distributing the information bits between m parallel polar codes such that each of the m parallel polar codes includes a subset of the information bits; splitting the subset of information bits in each of the m parallel polar codes into a protected information section and a full rate information section; protecting information bits in the protected information section of each of the m parallel polar codes; arranging a plurality of frozen bits in each of the m parallel polar codes; and generating a polar encoded codeword for each of the m parallel polar codes.

A receiver for receiving data in a broadcast system includes a broadcast receiver that receives, via the broadcast system, a receiver input data stream including plural channel symbols represented by constellation points in a constellation diagram. A demodulator demodulates the channel symbols into codewords and a decoder decodes the codewords into output data words. A broadband receiver obtains redundancy data via a broadband system, the redundancy data for a channel symbol including one or more least robust bits of the channel symbol or a constellation subset identifier indicating a subset of constellation points including the constellation point representing the channel symbol. The demodulator and/or the decoder is configured to use the redundancy data to demodulate the respective channel symbol and to decode the respective codeword, respectively.

The present disclosure includes apparatus, systems, and techniques relating to noise-predictive detector adaptation. A described technique includes operating a decoder system to decode codewords that are based on a received encoded signal by processing the codewords and exchanging information between path and code decoders, operating the path decoder to use estimation parameters to produce first and second paths based on a codeword of the codewords, operating the code decoder to produce a decoded path based on the codeword; determining a winning path of first and second paths based on whether the decoded path matches the first path or the second path; and updating, based on one or more error terms and the winning path, the estimation parameters to favor selection of the winning path by the path decoder and to disfavor selection of a losing path of the first and second paths by the path decoder.

A system and method for detecting a scrambling seed in communication between a drone and a controller are described. The system comprises a radio-frequency (RF) receiver configured to receive an RF signal transmitted between the drone and a controller. The RF signal includes scrambled data that contain repetitions of unscrambled data based on known scramblers with an unknown scrambling seed. The system further comprises a memory device in communication with a hardware processor and having stored computer-executable instructions to cause the hardware processor to identify the smallest number of bits required in each segment of scrambled data for data combining by finding an invertible predetermined matrix. The hardware processor is configured to determine the unknown scrambling seed based on a function combining the predetermined matrix, transition matrices of scramblers, and segments of received scrambled data.

A non-systematic convolutional decoder of a convolutionally encoded multi-level data stream includes a shift register and two or more paths of exclusive-OR (XOR) gates, arranged to reconstruct an original input information stream, each path having a quantiser arranged to quantise the signal to two levels, and a set of XOR gates arranged to match an encoding path in an associated convolutional encoder, and a selector arranged to feed an output from each path to a single input of the shift register. If the paths have differing values at their output, the selector may choose the value from the path based upon a function of the multi-level signals associated with each path, such as the path with the largest absolute signal level. The decoder provides a simple means for decoding signals while allowing the signal to also or instead be decoded using e.g. a Viterbi decoder if higher performance is required.

Systems and methods for the secure transmission of data and algorithms are disclosed. The coding and modulation schemes meet the need of low signal-to-noise (SNR) ratio applications in areas of high interference. A radio transmitter is used to transmit data signals and a radio receiver is used to receive signals. The new coding algorithms and modulation for wideband communication at very low SNR domains. Systems use orthogonal frequency-division multiplexing modulation and a channel pilot algorithm for timing synchronization and frame alignment. Systems also use an orthogonal code, a super orthogonal convolutional code, and a block code to achieve channel capacity within 80% of the Shannon limit in the subzero decibel (dB) domain with reasonable decoding complexity. In an implementation example given, a 12.5 MHz band radio can transmit at a 108 kbps user data rate at −20 dB SNR and escape adversity detection.

An aspect of present invention discloses a transceiver processing hardware (“TPH”) which is configured to process wireless information based on a constellation map. The TPH includes a minimum mean square error (“MMSE”), an inverse discrete Fourier transform (“IDFT”), and a demapper. The MMSE provides estimation of received bit stream, and the IDFT generates a list of samples associated with frequency of the bit stream. The demapper configured to discard unused constellation points includes a minimum function component (“MFC”) and a special treatment component (“STC”). While MFC is able to receive a bit stream representing a symbol corresponding to a quadrature amplitude modulation (“QAM”), the STC is configured to force one or more infinity values to facilitate generation of an LLR value representing a logic value of the symbol.

Certain aspects of the present disclosure relate to techniques and apparatus for enhanced decoding, for example, by providing a multi-phase tail biting convolutional code (TBCC) decoding algorithm. An exemplary method generally includes obtaining, via a wireless medium, a codeword encoded with a TBCC encoding scheme, generating metrics for candidate paths through trellis stages of a decoder, propagating information from at least one of the trellis stages to a later trellis stage, while generating the metrics, selecting a set of the candidate paths based on the propagated information, and decoding the encoded codeword by evaluating the selected set of candidate paths based, at least in part, on the generated metrics. Other aspects, embodiments, and features are claimed and described.

The present invention discloses an ML (Maximum Likelihood) detector. An embodiment of the ML detector comprises a search value selecting circuit and an ML detecting circuit. The search value selecting circuit is configured to select a first-layer search value. The ML detecting circuit is configured to carry out the following steps: selecting first-layer candidate values according to the first-layer search value, one of a reception signal and a derivative thereof, and one of a channel estimation signal and a derivative thereof, and adding one or more first-layer candidate value(s), if necessary; calculating second-layer candidate values according to all the above-mentioned first-layer candidate values, and adding one or more second-layer candidate value(s) and its/their corresponding first-layer candidate value(s), if necessary; and calculating log likelihood ratios according to the whole first-layer and second-layer candidate values.