Methods and apparatus for providing a demapping system with phase compensation to demap uplink transmissions. In an embodiment, a method is provided that includes detecting a processing type associated with a received uplink transmission, and when the detected processing type is a first processing type then performing the following operations: removing resource elements containing reference signals from the uplink transmission; layer demapping remaining resource elements of the uplink transmission into two or more layers; phase compensating all layers to generate phase compensated layers; and soft-demapping all phase compensated layers to produce phase compensated soft-demapped bits.

Aspects described herein relate to configuring a search space size for a demodulator to use in generating log likelihood ratios (LLRs) in demodulating received signals. In an aspect, an indication of a search space size for a demodulator to use in generating LLRs can be received from a base station, and a demodulation of one or more signals received in wireless communication can be performed by a node using the demodulator and based on the search space size. In another aspect, a search space size for the demodulator of the node to use in generating log likelihood ratios (LLRs) can be determined based on one or more signals transmitted by the node, and an indication of a search space size can be transmitted to the node.

Transmission quality is improved in an environment in which direct waves dominate in a transmission method for transmitting a plurality of modulated signals from a plurality of antennas at the same time. All data symbols used in data transmission of a modulated signal are precoded by hopping between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol in the frequency domain and the time domain all differ. A modulated signal with such data symbols arranged therein is transmitted.

Consistent with the present disclosure, an encoder circuit is provided at a transmit side of an optical fiber link that maps an input sequence of bits of fixed length k a sequence of symbols of a codeword of length n, such that the symbols of the codeword define a predetermined transmission probability distribution. Preferably, each symbol of the codeword is generated during a corresponding clock cycle, such that after n clock cycles, a complete codeword corresponding to the input bit sequence is output. On a receive end of the link, a decoder is provided that outputs the k-bit sequence every n clock cycles. Accordingly, buffers need not be provided at the output of the encoder and the input of the decoder, such that processing of the input sequence, codewords, and output sequence may be achieved efficiently without large buffers and complicated circuitry. Moreover, the input sequence, with any binary alphabet may be matched to a desired output distribution with any arbitrary alphabet. Accordingly, probabilistic constellation shaping may be achieved over constellations of arbitrary size. In addition, relatively long codewords, may be encoded and decoded with the apparatus and method disclosed herein. Accordingly, for a fixed SNR a higher SE (more bits per symbol) can be achieved. Alternatively, for a fixed SE, a lower SNR may be sufficient. Moreover, the resulting SE may be finely tailored to a particular optical link SNR to provide data transmission rates that are higher than the low order modulation formats that would otherwise be employed for optical signals carried by such links.

A receiver for a passive optical network is provided. The receiver includes an analog-to-digital converter circuitry configured generate a digital receive signal based on an analog receive signal. The analog receive signal is based on an optical receive signal encoded with a binary transmit sequence. The receiver additionally comprises linear equalizer circuitry configured to generate an equalized receive signal by linearly equalizing the digital receive signal. Further, the receiver comprises secondary equalizer circuitry configured to generate soft information indicating a respective reliability of elements in the equalized receive signal using the Viterbi algorithm. In addition, the receiver comprises decoder circuitry configured to generate a digital output signal based on the soft information using soft decision forward error correction.

Apparatuses, systems, and techniques to demodulate data for fifth-generation (5G) new radio (NR). In at least one embodiment, a processor includes one or more circuits to use a parallel processor to determine a signal value based, at least in part, on one or more predetermined probability values.

A reception device includes: a receiver that receives a multiplexed signal; a first demapper that demaps the multiplexed signal, with a second modulated symbol stream of a second data series being included in the multiplexed signal as an undefined signal component, to generate a first bit likelihood stream of a first data series; a second demapper that demaps the multiplexed signal, with a first modulated symbol stream of the first data series being included in the multiplexed signal as an undefined signal component, to generate a second bit likelihood stream of the second data series; a first decoder that performs error control decoding on the first bit likelihood stream to derive the first data series; and a second decoder that performs error control decoding on the second bit likelihood stream to derive the second data series.

An apparatus for processing a received radio signal includes at least one processor and at least one memory. The at least one memory storing computer program code. The at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus to at least in part perform processing (received radio signal data with first and second signal processing chains, which respectively include first and second processing modules configured to respectively determine first output and an estimation of the first output data, and determine second output data using a neural network based on the estimation; updating parameters of the neural network based on the first output data and the second output data; and after the updating, processing the received radio signal data with the second signal processing chain, without applying the first processing module.

Methods and apparatuses are described herein for feedback based midamble adaptation. For example, a first station (STA) may transmit, to a second STA, a request frame that includes an indicator indicating a request for midamble information. The first STA may receive, from the second STA, a response frame that includes the midamble information determined by the second STA based on one or more channel measurements associated with the second STA. The midamble information may include a midamble report, a Doppler measurement report, or the like. The midamble report or the Doppler measurement report may include at least one of a midamble periodicity, a mobility/Doppler level, or the like. Based on the midamble information, the first STA may generate a physical layer convergence procedure (PLCP) protocol data unit (PPDU) that includes at least one midamble within a data portion of the PPDU.

A method and system for providing sub-band whitening are herein provided. According to one embodiment, a method includes deriving an estimated noise plus interference variance (NIVar) based on at least one legacy-long training field (LLTF) symbol from an LLTF signal; and updating an interference whitening (IW) factor by using a sub-band NIVar.