Abstract: A receiver configured for use in a communication system, such as a magnetic recording channel, and having a soft-output channel detector provided with a soft-input/soft-output (SISO) modulation codec for parity bits of a block error-correction code. A transmitter of the communication system is configured to encode data by applying a modulation code to the parity bits that have been generated using the block error-correction code. The SISO modulation codec provides an interface between the soft-output channel detector and a parity-check decoder that enables decoding iterations between them in a manner that takes into account inter-bit correlations imposed by the modulation code. In some embodiments, the soft-output channel detector is configured to operate at a fractional rate and to process an input signal carrying non-binary symbols, and the parity-check decoder is configured to apply parity-check-based decoding that is based on a non-binary low-density parity-check code.

Abstract: A packet-router architecture in which buffer modules are interconnected by one or more interconnect fabrics and arranged to form a plurality of hierarchical buffer levels, with each higher buffer level having more buffer modules than a corresponding lower buffer level. An interconnect fabric is configured to connect three or more respective buffer modules, with one of these buffer modules belonging to one buffer level and the other two or more buffer modules belonging to a next higher buffer level. A buffer module is configured to implement a packet queue that (i) enqueues received packets at the end of the queue in the order of their arrival to the buffer module, (ii) dequeues packets from the head of the queue, and (iii) advances packets toward the head of the queue when the buffer module transmits one or more packets to the higher buffer level or to a respective set of output ports connected to the buffer module.

Abstract: A receiver configured for use in a communication system, such as a magnetic recording channel, and having a soft-output channel detector provided with a soft-input/soft-output (SISO) modulation codec for parity bits of a block error-correction code. A transmitter of the communication system is configured to encode data by applying a modulation code to the parity bits that have been generated using the block error-correction code. The SISO modulation codec provides an interface between the soft-output channel detector and a parity-check decoder that enables decoding iterations between them in a manner that takes into account inter-bit correlations imposed by the modulation code. In some embodiments, the soft-output channel detector is configured to operate at a fractional rate and to process an input signal carrying non-binary symbols, and the parity-check decoder is configured to apply parity-check-based decoding that is based on a non-binary low-density parity-check code.

Abstract: A communication system, such as a magnetic recording channel, configured to apply modulation coding to parity bits of a block error-correction code. An embodiment of the communication system may have a transmitter having two different modulation encoders, one configured to apply a first modulation code to information bits and the other configured to apply a second modulation code to the parity bits that have been generated from the information bits using a block error-correction code. Alternatively or in addition, an embodiment of the communication system may have a receiver that incorporates a soft modulation codec configured to use the second modulation code in the log-likelihood-ratio space to enable decoding iterations between a sequence detector and a parity-check decoder.

Abstract: A packet-router architecture in which buffer modules are interconnected by one or more interconnect fabrics and arranged to form a plurality of hierarchical buffer levels, with each higher buffer level having more buffer modules than a corresponding lower buffer level. An interconnect fabric is configured to connect three or more respective buffer modules, with one of these buffer modules belonging to one buffer level and the other two or more buffer modules belonging to a next higher buffer level. A buffer module is configured to implement a packet queue that (i) enqueues received packets at the end of the queue in the order of their arrival to the buffer module, (ii) dequeues packets from the head of the queue, and (iii) advances packets toward the head of the queue when the buffer module transmits one or more packets to the higher buffer level or to a respective set of output ports connected to the buffer module.