Ntwine, LLC

Roshmere, Inc.

University of California

Other

Sans R&d, LLC

Raytheon Company

Apsidon, Inc.

The Regents of the Unversilty of California

Nikola Alic

Andreja Radosevic

Eduardo Temprana Giraldo

Srdjan Brkic

Djordje Sarac

Stojan Radic

Ping Piu Kuo

Vahid Ataie

Daniel Esman

John G Proakis

Predrag Ivanis

Vanessa Lynn Karr

Ping-Piu Kuo

The technology relates to bandwidth constrained communication systems with neural network based detection. In some embodiments, a bandwidth constrained equalized transport (BCET) communication system comprises: a transmitter comprising an error control code encoder, a pulse-shaping filter, and a first interleaver; a communication channel; and a receiver comprising a neural network processing block that processes a received signal. The error control code encoder can append redundant information onto the signal. The pulse-shaping filter can intentionally introduce memory into the signal in the form of inter-symbol interference. The first interleaver can change a temporal order of the symbols in the signal. The neural network can be trained with positive mappings between transmitted and decoded training signals, or negative mappings between training signals and erroneous decoded signals that are known to contain errors.

Bandwidth constrained communication systems with neural network based detection

The present disclosure provides techniques for bandwidth constrained communication systems with frequency domain information processing. A bandwidth constrained equalized transport (BCET) communication system can include a transmitter, a communication channel, and a receiver. The transmitter can include a pulse-shaping filter that intentionally introduces memory into a signal in the form of inter-symbol interference, an error control code (ECC) encoder, a multidimensional fast Fourier transform (FFT) processing block that processes the signal in the frequency domain, and a first interleaver. The receiver can include an information-retrieving equalizer, a deinterleaver with an ECC decoder, and a second interleaver joined in an iterative ECC decoding loop.

Bandwidth constrained communication systems with frequency domain information processing

The technology relates to bandwidth constrained communication systems with neural network based detection. In some embodiments, a bandwidth constrained equalized transport (BCET) communication system comprises: a transmitter comprising an error control code encoder, a pulse-shaping filter, and a first interleaver; a communication channel; and a receiver comprising a neural network processing block that processes a received signal. The error control code encoder can append redundant information onto the signal. The pulse-shaping filter can intentionally introduce memory into the signal in the form of inter-symbol interference. The first interleaver can change a temporal order of the symbols in the signal. The error control code encoder can be a low-density parity-check (LDPC) error control code encoder. The neural network can be trained with positive mappings between transmitted and decoded training signals, or negative mappings between training signals and a null space of an LDPC generation matrix.

The present disclosure provides techniques for bandwidth constrained communication systems with frequency domain information processing. A bandwidth constrained equalized transport (BCET) communication system can include a transmitter, a communication channel, and a receiver. The transmitter can include a pulse-shaping filter that intentionally introduces memory into a signal in the form of inter-symbol interference, an error control code (ECC) encoder, a multidimensional fast Fourier transform (FFT) processing block that processes the signal in the frequency domain, and a first interleaver. The receiver can include an information-retrieving equalizer, a deinterleaver with an ECC decoder, and a second interleaver joined in an iterative ECC decoding loop. The communication system can be bandwidth constrained, and the signal can comprise an information rate that is higher than that of a communication system without intentional introduction of the memory at the transmitter.

The present application is directed to techniques and systems for extension of unrepeatered submarine fiber links to provide an increase in reach of unrepeatered fiber transmission. Both single channel unrepeatered systems and multiple channel unrepeatered systems can be used. The multiple channel unrepeatered systems can further employ nonlinearity compensation. The present application is also directed to methods of signal transmission using the unrepeatered systems.

Increase in reach of unrepeatered fiber transmission

A system and method for mitigating nonlinearity in an optical communication link with multiple carriers uses mutual frequency referencing to stabilize at least a portion of the multiple carriers. Using at least one frequency-referenced signal, carrier nonlinearity can be determined and compensated within the link by pre-distortion, back-propagation, or a combination of both. Mutual frequency referencing may be performed at the emitting end of the link, at the receiving end, or a combination of both.

Nonlinearity cancellation in fiber optic transmission based on frequency-mutually-referenced carriers

In some embodiments, a bandwidth constrained equalized transport (BCET) communication system comprises a transmitter that transmits a signal, a communication channel that transports the signal, and a receiver that receives the signal. The transmitter can comprise a pulse-shaping filter that intentionally introduces memory into the signal, and an error control code encoder that is a low-density parity-check (LDPC) error control code encoder. The error control encoder comprises code that is optimized based on the intentionally introduced memory into the signal, a code rate, a signal-to-noise ratio, and an equalizer structure in the receiver. In some embodiments, the communication system is bandwidth constrained, and the transmitted signal comprises an information rate that is higher than for an equivalent system without intentional introduction of the memory at the transmitter.

Bandwidth constrained communication systems with optimized low-density parity-check codes

The present disclosure provides techniques for bandwidth constrained communication systems with frequency domain information processing. A bandwidth constrained equalized transport (BCET) communication system can include a transmitter, a communication channel, and a receiver. The transmitter can include a pulse-shaping filter that intentionally introduces memory into a signal in the form of inter-symbol interference, an error control code (ECC) encoder, a multidimensional fast Fourier transform (FFT) processing block and a multidimensional inverse FFT processing block that process the signal in the frequency domain, and a first interleaver. The receiver can include an information-retrieving equalizer, a deinterleaver with an ECC decoder, and a second interleaver joined in an iterative ECC decoding loop. The communication system can be bandwidth constrained, and the signal can comprise an information rate that is higher than that of a communication system without intentional introduction of the memory at the transmitter.

A spread spectrum receiving method receives a spread spectrum signal. An optical signal frequency comb is generated. Modes of the optical signal frequency comb are modulated with a received spread spectrum signal. An optical local oscillator comb is generated that is mutually coherent with the signal frequency comb. A code word is applied to the local oscillator comb. The combs are combined and the received spread spectrum signal is detected from the combined combs.

Comb assisted spread-spectrum method

The present invention is directed to techniques and systems for extension of unrepeatered submarine fiber links to provide an increase in reach of unrepeatered fiber transmission. Both single channel unrepeatered systems and multiple channel unrepeatered systems can be used. The multiple channel unrepeatered systems can further employ nonlinearity compensation. The present invention is also directed to methods of signal transmission using the unrepeatered systems.

A spread spectrum receiver and receiving methods are provided. Received data is physically reconstructed in the optical domain using a pair of coherently coupled frequency combs, one modulated by the received signal and one modulated by the code word, and then detecting the received data with a subrate detector comprised of detector array. Particular methods and receivers extract a timing difference between the received spread spectrum signal and the codeword from the phase shifts of Fourier terms of the product of the received spread spectrum signal and the codeword that can be measured from the combined combs.

Comb assisted spread-spectrum receiver and reception methods

A photonically-assisted cyclostationary analyzer eliminates the need for high-bandwidth digitization and real-time Fourier processors by using mutually-coherent frequency combs to generate a Fourier representation of the received signal in a computation-free manner.

Comb-assisted cyclostationary analysis

In a system, known digital representations are generated, and test analog signals are generated using the known digital representations. The test analog signals are transmitted using a transmitter of a transmission system. The test analog signals are received using a receiver of the transmission system and used to generate test received digital representations. The test received digital representations are cross-correlated with the known digital representations to generate a mixing matrix. The mixing matrix is inverted to generate a de-mixing matrix, which is applied to subsequent digital data to be encoded onto a signal and transmitted by the transmitter to generate pre-compensated digital data.

Crosstalk correction using pre-compensation

In a system, known digitizer signals (known analog signals or digital representations of known analog signals) are generated. The known digitizer signals are input into digitizers (analog-to-digital converter (ADCs) or digital-to-analog converter (DACs)) to output generated digitizer signals (generated digital representations or generated analog signals). The generated digitizer signals are analyzed in relation to the known digitizer signals to generate coupling coefficients, which can be either scalar quantities or finite-impulse-response (FIR) filter functions. Subsequent digitizer signals are generated. The subsequent digitizer signals are modified using the coupling coefficients to generate modified digitizer signals according to formulae. The modified digitizer signals are used directly as digital representations, or are input to the DACs to output modified analog signals that substantially match subsequent analog signals.

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Nikola Alic