A method and structure for probabilistic shaping and compensation techniques in coherent optical receivers. According to an example, the present invention provides a method and structure for an implementation of distribution matcher encoders and decoders for probabilistic shaping applications. The techniques involved avoid the traditional implementations based on arithmetic coding, which requires intensive multiplication functions. Furthermore, these probabilistic shaping techniques can be used in combination with LDPC codes through reverse concatenation techniques.

Various embodiments of the present disclosure relate to transmitter systems, methods, and instructions for signal predistortion. The transmitter system includes a primary digital predistortion (DPD) layer and a secondary DPD layer. The primary DPD layer includes a DPD coefficient estimation module configured to update primary signal generation coefficients based on comparing a secondary predistorted signal (U.sub.out) with a detected feedback signal (Y.sub.out), and a primary distortion compensation processing module configured to generate a primary predistorted signal (U.sub.out′) based on the secondary predistorted signal (U.sub.out) using the updated primary signal generation coefficients. The secondary DPD layer includes a signal characteristic estimation module configured to update secondary signal generation coefficients based on comparing an input signal (S.sub.in) with the detected feedback signal (Y.sub.out), and a secondary distortion compensation processing module configured to generate the secondary predistorted signal (U.sub.out) based on the input signal (S.sub.in) using the updated secondary signal generation coefficients.

Various embodiments of the present disclosure relate to transmitter systems, methods, and instructions for signal predistortion. The transmitter system includes an intermodulation distortion (IMD) filter module configured to filter a detected feedback signal (Y.sub.in) to generate a targeted filtered signal (Y.sub.out), a digital pre-distortion (DPD) coefficient estimation module configured to update signal generation coefficients based on comparing an input signal (S.sub.in) with the targeted filtered signal (Y.sub.out), and a distortion compensation processing module configured to generate a pre-distorted signal (U.sub.out) based on the input signal (S.sub.in) using the updated signal generation coefficients.

Various embodiments of the present disclosure relate to transmitter systems, methods, and instructions for signal predistortion. The transmitter system includes a signal decomposition module configured to extract a low-frequency signal (S.sub.lo) and a high-frequency signal (S.sub.hi) from an input signal (S.sub.in); a distortion compensation processing module configured to generate a pre-distorted low-frequency signal (U.sub.lo) and a pre-distorted high-frequency signal (U.sub.hi) based on the received low-frequency and high-frequency signals using signal generation coefficients; a signal combining module configured to combine the pre-distorted low-frequency signal (U.sub.lo) and the pre-distorted high-frequency signal (U.sub.hi); and a signal characteristic estimation processing module configured to update the signal generation coefficients used by the distortion compensation processing module based on comparing the low-frequency signal (S.sub.lo) and the high-frequency signal (S.sub.hi) with a detected feedback low-frequency signal (Y.sub.lo) and a detected feedback high-frequency signal (Y.sub.hi).

The present invention relates to a method and apparatus for monitoring a downlink control channel by a first terminal having a single RX chain in a wireless communication system. Specifically, the present invention comprises the steps of: setting a particular gap for a resource area related to device-to-device (D2D) signal transmission/reception; and monitoring a wide area network (WAN) communication-based downlink control channel on the basis of a timer performed according to a discontinuous reception (DRX) operation, wherein the timer is counted on the basis of at least one subframe which does not overlap with the particular gap, and the particular gap is a time interval set for allowing the single RX chain to cover a switching operation between WMN communication and D2D communication.

A receiving system of the present disclosure includes: a plurality of demodulators; an add-on generating one stream based on an output from each of the demodulators; a selector selecting and outputting one among an output from one of the demodulators, namely the demodulator, and the one stream from the add-on; and a back-end processor generating an output for a display based on an output from the selector and the other demodulators, namely the demodulators. The selector selects an output from the demodulator in a single channel transmission mode, and selects the stream from the add-on in a multiple channel transmission mode.

A technique of separating a sequence of modulation shift keying (MSK) symbols into a first portion and a second portion and separately comparing the first portion of the sequence of MSK symbols and the second portion of the sequence of MSK symbols against a first portion of a reference sequence of MSK symbols and a second portion of the reference sequence of MSK symbols allows a low complexity detection of a start field delimiter in a wireless communication packet.

Various embodiments of the present disclosure relate to transmitter systems, methods, and instructions for signal predistortion. The transmitter system includes a signal decomposition module configured to extract a low-frequency signal (S.sub.lo) and a high-frequency signal (S.sub.hi) from an input signal (S.sub.in); a distortion compensation processing module configured to generate a pre-distorted low-frequency signal (U.sub.lo) and a pre-distorted high-frequency signal (U.sub.hi) based on the received low-frequency and high-frequency signals using signal generation coefficients; a signal combining module configured to combine the pre-distorted low-frequency signal (U.sub.lo) and the pre-distorted high-frequency signal (U.sub.hi); and a signal characteristic estimation processing module configured to update the signal generation coefficients used by the distortion compensation processing module based on comparing the low-frequency signal (S.sub.lo) and the high-frequency signal (S.sub.hi) with a detected feedback low-frequency signal (Y.sub.lo) and a detected feedback high-frequency signal (Y.sub.hi).

A method and structure for probabilistic shaping and compensation techniques in coherent optical receivers. According to an example, the present invention provides a method and structure for an implementation of distribution matcher encoders and decoders for probabilistic shaping applications. The techniques involved avoid the traditional implementations based on arithmetic coding, which requires intensive multiplication functions. Furthermore, these probabilistic shaping techniques can be used in combination with LDPC codes through reverse concatenation techniques.

A technique of separating a sequence of modulation shift keying (MSK) symbols into a first portion and a second portion and separately comparing the first portion of the sequence of MSK symbols and the second portion of the sequence of MSK symbols against a first portion of a reference sequence of MSK symbols and a second portion of the reference sequence of MSK symbols allows a low complexity detection of a start field delimiter in a wireless communication packet.