Patent classifications
H04L25/03318
LOW POWER HIGH SENSITIVITY SENSE AMPLIFIER LATCH WITH COMPLIMENTARY OUTPUTS IN RESET MODE
A sense amplifier latch (SAL) provides complimentary outputs in a reset phase to feed them directly to the Decision Feedback Equalizer (DFE) taps from SAL soft decision (d1x & d1xb) to improve the performance of DFE first tap 1-UI (one unit-interval) critical timing. The latch generates the complimentary resetting values on differential outputs in reset time. The latch enables in the required time i.e., once evaluation is done it shuts the current sinking path. The latch can extrapolate to rail-to-rail input common mode range of operation.
Systems and methods for phase noise mitigation in optical superchannels
A receiver architecture is described for phase noise compensation in the presence of inter-channel interference (ICI) and inter-symbol interference (ISI), particularly for time-frequency packing (TFP) transmissions. The receiver includes a coarse phase noise (PN) estimator, a PN compensation module, an ICI cancellation module, an ISI compensation module, a FEC decoder, and an iterative PN estimator. The iterative PN estimator receives log likelihood ratio (LLR) information from the decoder and provides an iterative PN estimation to the PN compensation module. The decoder also provides LLR to the ISI compensation module, and to at least one other receiver for another subchannel that is immediately adjacent in frequency. The ICI cancellation module receives decoder output from at least one adjacent subchannel, which the ICI cancellation module uses to provide a ICI-cancelled signal.
USER EQUIPMENT INITIATED DATA AIDED PHASE TRACKING REFERENCE SIGNALS ON MULTIPLE LAYERS OF A COMMUNICATION LINK
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may transmit a request, for an uplink transmission or a downlink transmission, for data aided phase tracking reference signals (PT-RSs) on multiple layers of a communication link; and communicate the uplink transmission or the downlink transmission based at least in part on the request. Numerous other aspects are provided.
Multi-Stage Equalizer for Inter-Symbol Interference Cancellation
An equalizer includes a first feed-forward stage that provides a measure of low-frequency IS I and a second feed-forward stage that includes a cascade of stages each making an IS I estimate. The IS I estimate from each stage is further equalized by application of the measures of low-frequency IS I from the first feed-forward stage and fed to the next in the cascade of stages. The IS I estimate from the stages thus become progressively more accurate. The number of stages applied to a given signal can be optimized to achieve a suitably low bit-error rate. Power is saved by disabling stages which are not required to meet that goal.
Soft value extraction method and device applicable to OvXDM system, and OvXDM system
This application discloses a soft value extraction method and device applicable to an OvXDM system, and the OvXDM system. In the method, waveform coding is performed on all symbols in a hard value sequence, to generate a predictive value after overlapped coding; the symbols in the hard value sequence are reversed one by one, and overlapped coding is performed on each reversed symbol and associated symbols before and after the reversed symbol, to generate a predictive value of the reversed symbol; and for each symbol in the hard value sequence, a soft value of the current symbol is calculated based on A(.sup.+1
.sup.1), where A is a coefficient related to a channel type,
.sup.+1=y.sub.rxy.sup.+1, and
.sup.1=y.sub.rxy.sup.1.sup.2; if y.sup.+1 is a predictive value of the symbol obtained after overlapped coding and before reversing, y.sup.1 is a predictive value of the symbol obtained after overlapped coding and reversing; and y.sub.rx is a received signal sequence.
Optical transmission apparatus and method for processing signal based on direct detection
An optical transmission method for processing a signal based on direct detection includes setting, by an equalizer, an adaptive equalization coefficient by performing an equalization process during a training symbol field section in a frame of a received signal, performing, by a channel estimator, channel estimation to perform an equalization process of a soft output maximum likelihood sequence equalizer (MLSE) during the training symbol field section, driving the soft output MLSE, and compensating for, by the soft output MLSE, distortion of the received signal during a data symbol field section in the frame on the basis of the adaptive equalization coefficient and an estimated result value of a channel, and recovering, by an error corrector which allows soft-decision processing to be performed, the received signal by performing error correction on the received signal in which the distortion is compensated for.
ADAPTIVE DETECTION FUNCTION BASED ON STATISTICAL PROPAGATION CHANNEL ESTIMATION FOR GNSS RECEIVERS
Method and device to decode a GNSS signal in a GNSS receiver include a channel decoder, wherein the GNSS receiver is configured to: determine parameters relative to a statistical propagation channel model, the statistical propagation channel model being a Prieto channel model or a Perez-Fontan channel model, compute a statistical channel attenuation from the statistical propagation channel model using the parameters, compute LLRs from a detection function adapted to the statistical propagation channel model using the computed statistical channel attenuation, and use the said LLRs to feed the channel decoder.
OPTICAL TRANSMISSION APPARATUS AND METHOD FOR PROCESSING SIGNAL BASED ON DIRECT DETECTION
An optical transmission method for processing a signal based on direct detection includes setting, by an equalizer, an adaptive equalization coefficient by performing an equalization process during a training symbol field section in a frame of a received signal, performing, by a channel estimator, channel estimation to perform an equalization process of a soft output maximum likelihood sequence equalizer (MLSE) during the training symbol field section, driving the soft output MLSE, and compensating for, by the soft output MLSE, distortion of the received signal during a data symbol field section in the frame on the basis of the adaptive equalization coefficient and an estimated result value of a channel, and recovering, by an error corrector which allows soft-decision processing to be performed, the received signal by performing error correction on the received signal in which the distortion is compensated for.
RECEPTION DEVICE, COMMUNICATION SYSTEM, AND METHOD FOR CALCULATING LIKELIHOOD OF MODULATION SIGNAL
A reception device according to the present invention includes: a signal division unit; a maximum-likelihood point search unit; a maximum-likelihood point search unit; a replica-vector calculation unit; a replica-vector calculation unit; and a likelihood calculation unit. Wherein, the signal division unit divides a reception signal including a plurality of multiplexed signals respectively into a real component and an imaginary component; the maximum-likelihood point search unit narrows down candidate signal points; the maximum-likelihood point search unit to narrows down candidate signal points; the a replica-vector calculation unit calculates a first replica vector by using the first candidate signal point; the replica-vector calculation unit calculates a second replica vector by using the second candidate signal point; and the likelihood calculation unit calculates a likelihood of the modulation signal by using the first replica vector and the second replica vector.
Apparatus and method for processing a received input signal containing a sequence of data blocks
An apparatus and method are provided for processing a received input signal comprising a sequence of data blocks. Counter circuitry within the apparatus is arranged to receive a digital representation of the input signal, and for each data block generates a count value indicative of occurrences of a property of the digital representation (for example a rising edge or a falling edge) during an associated data block transmission period. Quantization circuitry then maps each count value to a soft decision value from amongst a predetermined set of soft decision values, where the number of soft decision values in the predetermined set exceeds a number of possible data values of the data block. The output circuitry then generates a digital output signal in dependence on the soft decision values. Such an apparatus has been found to provide a low power technique for a receiver, whilst still enabling the improved sensitivity benefits of using soft decisions to be achieved, and allows the apparatus to be constructed using all digital components.