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.

Deterioration of convergence performance or operational stability due to an increase in constraint length is suppressed when coefficients are updated, so that decoding performance is improved. A decoding device according to the present technology includes an adaptive equalization unit that performs adaptive equalization, an adaptive maximum likelihood decoding unit that causes an identification point of maximum likelihood decoding to adaptively follow a characteristic of an input signal, a target waveform generation unit that, by convoluting a partial response coefficient into a decoded value, generates an equalization target waveform of the adaptive equalization which is performed by the adaptive equalization unit, an error signal generation unit that generates, as an equalization error signal, an error signal between the equalization target waveform and an equalized signal, and a coefficient updating unit that, through least-square-method computation for minimizing a correlation between the decoded value and the equalization error signal, updates the partial response coefficient which is used by the target waveform generation unit to generate the equalization target waveform.

In one aspect, a method includes: receiving, in a configurator for a wireless receiver, a plurality of user-defined parameters for configuring the wireless receiver for wireless communication, the user-defined parameters including pulse shaping information of a pulse shaper of a wireless transmitter to be in communication with the wireless receiver and channel filter information of a channel filter of the wireless receiver; generating a plurality of frequency signals based on a corresponding plurality of predetermined bit sequences and at least two of the plurality of user-defined parameters including the pulse shaping information and the channel filter information; setting a first nominal symbol value based at least in part on an oversampling rate for a demodulator of the wireless receiver; and configuring the wireless receiver with the first nominal symbol value to cause the demodulator of the wireless receiver to operate using the first nominal symbol value.

New sequences have been proposed and/or adopted for short Physical Uplink Control Channel communications between base stations and UEs. In an exemplary embodiment, a UE communicates with a base station based on sequence groups that include the new sequences, where the new sequences are allocated to different sequence groups based, at least in part, on correlations with other existing sequences included in individual sequence groups.

A reception device 20 is configured to include a separation means 21 and a plurality of optical reception means 22. Each optical reception means 22 further includes an optical/electrical conversion means 23, a reception coefficient computation means 24, and a band restoration means 25. The separation means 21 separates a multiplexed signal into which signals of respective channels to which spectral shaping that narrows bandwidth to less than or equal to a baud rate is applied as band narrowing filter processing on the transmission side, based on characteristics of a transmission line are multiplexed at spacings less than or equal to the baud rate. Each band restoration means 25 applies processing having inverse characteristics to those of the band narrowing filter processing to a reception signal, based on the band narrowing parameter acquired by the reception coefficient computation means 24 and thereby restores the band of the reception signal.

A method includes: generating a trellis; generating one or more predicted symbols using a first non-linear model; computing and saving two or more branch metrics using a priori log-likelihood ratio (LLR) information, a channel observation, and the one or more predicted symbols; if alpha forward recursion has not yet completed, generating alpha forward recursion state metrics using a second non-linear model; if beta backward recursion has not yet completed, generating beta backward recursion state metrics using a third non-linear model; if sigma forward recursion has not yet completed, generating sigma forward recursion state metrics using the branch metrics, the alpha state metrics, and the beta backward recursion state metrics; generating extrinsic information comprising a difference of a posteriori LLR information and the a priori LLR information; computing and feeding back the a priori LLR information; and calculating the a posteriori LLR information.

The invention comprises a method for controlling a gain of a multi-stage equalizer of a serial data receiver, applied to the serial data receiver comprising the multi-stage equalizer, wherein the method comprises: Step S1, enabling the serial data receiver to receive a set of serial data; Step S2, selecting a plurality of continuous data sequences from the set of serial data according to a preset first rule; Step S3, extracting a predetermined bit from each of the plurality of continuous data sequences; Step S4, calculating an equalization gain identifier corresponding to each of the plurality of continuous data sequences according to a predetermined bit in each of the plurality of continuous data sequences; Step S5, obtaining an optimized equalization gain identifier through calculation according to each of the equalization gain identifiers; and Step S6, controlling a gain value of the multi-stage equalizer according to the optimized equalization gain identifier.

A method and apparatus for adapting, in parallel, two operating parameters associated with an equalizer circuit is disclosed. A control circuit may be configured to initialize a first operating parameter to an initial value, and modify a second operating parameter based upon the initial value of the first parameter. In response to determining a peak amplitude of an output signal of the equalizer circuit is less than a threshold value, the control circuit may be further configured to select a new value for the first operating parameter and adapt, in response to the change in the first operating parameter, the second operating parameter based on a performance metric of the equalizer circuit.

The present application discloses a forward and backward smooth decoding method and device suitable for an OvXDM system, and a system. Importance weights of particles in a particle set corresponding to a symbol are calculated by using a forward process and a backward process, and screening is performed with reference to forward importance weights of particles and backward importance weights of particles, to output a final decoding sequence.

An iterative two dimension equalizer usable in a receiver of orthogonal time frequency space (OTFS) modulated signals is described. In one configuration of the equalizer, a forward path generates, from received time-frequency domain samples and a channel estimate, estimates of data bits and likelihood numbers associated with the estimates of data bits, generated by delay-Doppler domain processing. In the feedback direction, the estimates of data bits are used to generate symbol estimates and autocorrelation matrix estimate in the time domain. In another configuration, a soft symbol mapper is used in the feedback direction for directly generating the feedback input symbol estimate without having to generate estimates of data bits.