A PAM4 receiver including an adaptive continuous-time linear equalizer and a method for training the same are disclosed. The PAM4 receiver and the method for training the same of the present invention employs a training pattern including a first training data pattern and second training data pattern to adaptively tune the PAM4 receiver to achieve accurate data reception and long-distance, high-speed communication.

A PAM4 receiver including an adaptive continuous-time linear equalizer and a method for training the same are disclosed. The PAM4 receiver and the method for training the same of the present invention employs a training pattern including a first training data pattern and second training data pattern to adaptively tune the PAM4 receiver to achieve accurate data reception and long-distance, high-speed communication.

This application provides a training sequence transmission method and apparatus. The method includes: A first AP broadcasts a trigger frame, where the trigger frame indicates a time sequence of separately sending channel sounding frames by N STAs, and N is an integer greater than 1. The first AP receives the channel sounding frames sequentially sent by the N STAs, where one channel sounding frame includes one or more training sequences. In this solution, only one trigger frame needs to be sent, so that the N STAs can be triggered to separately report channel sounding frames to M+1 APs. However, in the conventional technology, each AP needs to send one channel training request to each STA, that is, N×(M+1) channel training requests are sent in total, to trigger each STA to report a training sequence. Therefore, this solution can significantly reduce signaling overheads.

During a training procedure for communicating via a full-duplex communication link, a first communication device receives training information from a second communication device. The training information corresponds to first signal processing parameters developed at the second communication device for use by the second communication device to process signals received by the second communication device via the full-duplex communication link. After receiving the training information from the second communication device, the first communication device develops second signal processing parameters to be used by the first communication device to process signals received by the first communication device via the full-duplex communication link. The second signal processing parameters are developed using the training information received from the second communication device.

The present invention discloses a receive data equalization apparatus. A delay-compensating calculation circuit retrieves training data groups of a training data signal to retrieve total delay amount, generate signed compensation amounts according to a relation among training data contents of training data in each of the training data groups to generate total compensation amount accordingly, and solve equations that correspond total delay amount of the training data groups to the total compensation amount to obtain each of the compensation amounts. A receive data equalization circuit receives the compensation amounts and retrieves a receive data group in a receive data signal, generate signed receive compensation amounts according to a relation among receive data contents of receive data in the receive data group to generate a total receive compensation amount accordingly to perform equalization on a terminal edge of the receive data group according to the total receive compensation amount.

A secure training sequence (STS) is included in wireless packets communicated between electronic devices to assist with channel estimation and wireless ranging. The STS includes multiple STS segments generated based on outputs from a cryptographically secure pseudo-random number generator (CSPRNG), the STS segments being separated by guard intervals and formatted in accordance with an 802.15.4 data symbol format that uses burst position modulation (BPM) and binary phase shift keying (BPSK) to map bits from the CSPRNG to burst positions and pulse polarities for the STS symbols. Both a first electronic device, which generates the STS, and a second electronic device, which estimates a communication channel using the STS, have prior private knowledge of cryptographic keys required to generate a non-repetitive single-use pseudo-random (PR) sequence by the CSPRNG. The STS includes two burst position intervals per STS symbol and two possible burst positions within each burst position interval.

The received RF signal includes a first RF signal encoding a first orthogonal frequency-division multiplexing (OFDM) symbol of a first long-term evolution (LTE) V2X data packet. A legacy long training field (L-LTF) symbol is determined using the received RF signal (608), a channel estimation is calculated (612) using the L-LTF symbol, and legacy signal (L-SIG) field control bits are determined (614) from the received RF signal, the L-SIG field control bits including a plurality of IQ samples. A plurality of candidate L-SIG decodings are generated (618) using the IQ samples and the channel estimation, wherein each candidate L-SIG decoding of the plurality of L-SIG decodings is generated by setting a different number of IQ samples in the L-SIG field control bits to zero values (616), and a first L-SIG decoding of the plurality of candidate L-SIG decodings is identified (624). A data field from the received RF signal is decoded using the first L-SIG decoding (626).

A device, in a training phase, obtains Channel State Information (CSI) for one or more links between another device and at least one Access Point (AP), and in the training phase, estimates location information of the other device based on at least one geometric localization technique; and generates a database comprising CSI of the one or more links, each CSI being associated with an estimated location information. Further, a device, in a testing phase, obtains a database from another device, wherein the database comprises CSI of one or more links, each CSI being associated with an estimated location information, and in the testing phase, the device estimates CSI for one or more links between the device and at least one AP, and determine location information based on the estimated CSI of the one or more links and the database.

Various embodiments relate to a method for processing received distributed multiple-input and multiple-output (DMIMO) OFDM signals from a plurality of transmitters, including: performing an initial carrier frequency offset (CFO) correction; receiving a plurality of OFDM symbols; re-constructing the channel every N symbols based upon a channel estimate for each transmitter and an estimate of residual CFO for each of the transmitters based upon the long term fields (LTF), wherein N is an integer; and equalizing the received OFDM symbols using the re-constructed channel.

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.