Nokia Solutions and Networks Oy

Nokia Technologies Oy

Yannick Lefevre

Jochen Maes

Amitkumar Mahadevan

Werner Coomans

Werner Van Hoof

Wouter Lanneer

Paschalis Tsiaflakis

Vincent Etienne Houtsma

Bart J Pauwels

Doutje T Van Veen

Joon Ho Cho

Paul Henri Marie Cautereels

Adriaan De Lind Van Wijngaarden

Michaël Fivez

Michiel Verplaetse

Laurens Breyne

Bart Joseph Pauwels

An optical network unit (ONU) includes a transmitter and receiver to optically communicate with an optical line terminal (OLT) of a passive optical network. The ONU is configured to send an acknowledgment message to the OLT in response to a burst-profile message unicast by the OLT. The acknowledgement message indicates unsupported forward error correction (FEC) code in response to the burst-profile message identifying an FEC code for upstream transmission and the ONU not supporting the FEC code for upstream transmission to the OLT.

Acknowledgment-based flexible FEC selection

A digital receiver based on one-dimensional hard demapping of an input symbol stream (FEC encoded) is configured to utilize LLRs created to have bit-specific magnitude values to improve the probability that the included decoder (such as an LDPC decoder) properly recovers each bit from the original stream. The digital receiver may be used with various types of data modulation schemes (e.g., PAM3, PAM4, DSQ8, etc.), with a specific set of LLR magnitudes created for each modulation scheme.

One-dimensional hard-input FEC receiver for digital communication

In one embodiment, an apparatus is configured to perform mapping an interleaved bit stream into a sequence of 4-level pulse amplitude modulation (PAM4) labels according to a mapping scheme, with a respective PAM4 label including a least significant bit (LSB) and a most significant bit (MSB) respectively corresponding to a bit in the interleaved bit stream; transmitting a sequence of PAM4 symbols generated based on the sequence of PAM4 labels to the ONUs; and wherein, bits from respective one of the N codewords are assigned to LSBs of a first subset of labels, and to MSBs of a second subset of labels, with the first and the second subset of labels being determined based on the interleaving scheme and the mapping scheme and respectively comprising labels located N labels apart in the sequence of PAM4 labels.

Method and apparatus for downstream transmission

The method includes sending a first frame of a first modulation format that is suitable for a first group of receivers before sending a second frame of a second modulation format that is suitable for a second group of receivers, wherein the first modulation format is a higher modulation format than the second modulation format, and wherein the method further includes inserting into the first frame at least one symbol of the second modulation format at at least one outer edge of the first frame.

Apparatus and a method for transmitting and receiving in a passive optical network

An apparatus grouping data units for optical network units into groups of Encapsulation Method, EM, frame(s), wherein a respective group of EM frame(s) include data units addressed to a respective subset of ONUs, generating, based on the groups of EM frame(s), a Framing Sublayer payload including at least one specific frame, wherein, the specific frame includes a length indicator determined in relation to the length of the group(s) of EM frame(s) that is(are) directly following the specific frame and is(are) addressed to at least one subset of ONUs; instructing the ONUs assigned to at least one of said at least one subset to process the EM frame directly following the specific frame, and instructing the ONUs not assigned to the at least one subset to process the EM frame that is indicated by the length indicator of the specific frame; and transmitting the Framing Sublayer payload to the ONUs.

Method and apparatus for ONU grouping

An upstream (US) optical line terminal (OLT) for a passive optical network having at least one downstream (DS) optical network unit (ONU). The OLT generates a trigger signal indicating a need to receive at least one US burst having a shortened codeword for a first forward error-correction (FEC) code. Based on the trigger signal, the OLT transmits a DS message instructing the ONU to transmit an US burst having a shortened codeword. The OLT receives and decodes the US burst having the shortened codeword using the first FEC code. During periods of high bit-error rate, the shortened codewords increase the ability of the OLT to decode the US bursts and keep communications from the ONU alive. The OLT can use the decoded US bursts to measure BER and, if appropriate, instruct the ONU to use a different FEC code.

Using shortened codewords in passive optical networks

The method includes transmitting by a first remote communication unit an upstream symbol with a first structure onto a first communication line at a reference time point trf, wherein the reference time point trf is determined based on a time of reception of a downstream symbol with the first structure tFDX_DS_RX and a first propagation delay over the first communication line tPD1, as trf=tFDX_DS_RX−tPD1; transmitting by a second remote communication unit an upstream symbol with a second structure onto the second communication line at tTDD_US_TX=trf−tPD2 during a time interval assigned for upstream transmission on the second communication line, wherein tPD2 is a second propagation delay over the second communication line, so that the upstream symbol with the second structure transmitted by the second remote communication unit arrives at the access node at the reference time point trf.

Method and apparatus for coordinating FDX and TDD communications in a communication system

The present disclosure relates to an equalizer training unit for deriving equalization parameters for compensating data-dependent distortion in received samples by use of a training sequence including a sequence p&#x3e;1 times and cyclically comprising N sub-sequences of respective combinations of L time-domain symbols of a modulation scheme, wherein the N sub-sequences are cyclically arranged in a selected order and such that L&#x2212;1 symbols of a respective sub-sequence overlap with symbols in the preceding and following sub-sequences. The present disclosure further relates to a training sequence generator unit for generative the training sequence and an equalizer employing the equalizer training unit.

Equalizer and an equalizer training unit for data-dependent distortion compensation

An apparatus, for use by an Optical Network Unit, performs receiving, from an Optical Line Terminal, a broadcast message including code set information indicating a first code set selected from a plurality of error correction code sets; determining whether the first code set is comprised in a group of code sets supported by the Optical Network Unit, wherein, the group of code sets includes at least one code set of the plurality of error correction code sets; and encoding an upstream transmission with the first code set, in case the first code set is included in the group of code sets.

Method and apparatus for ONU activation

Various example embodiments for supporting forward error correction (FEC) in a communication system are presented. Various example embodiments for supporting FEC in a communication system may include the selection of a FEC setting for a communication channel from a transmitter to a receiver, e.g., the selection of a FEC setting for a communication channel, the selection of a FEC setting for a data burst sent over a communication channel, the selection of a FEC setting for a portion of a data burst sent over a communication channel, switching between FEC settings for different portions of a data burst over a communication channel, or the like, as well as various combinations thereof.

Forward error correction control

According to example embodiments, the OLT includes at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the OLT to perform grouping data units for the ONUs in groups, wherein a group includes data units for a subset of the ONUs, encoding the groups of data units into respective sets of at least one codeword, interleaving the at least one codeword of the respective sets thereby obtaining a stream of codewords, and sequentially transmitting the stream of codewords to the ONUs.

Optical line terminal and an optical network unit and methods therefor

The method includes transmitting by a first remote communication unit an upstream symbol with a first structure onto a first communication line at a reference time point t, wherein the reference time point tis determined based on a time of reception of a downstream symbol with the first structure tand a first propagation delay over the first communication line t, as t=t&#x2212;t; transmitting by a second remote communication unit an upstream symbol with a second structure onto the second communication line at t=t&#x2212;tduring a time interval assigned for upstream transmission on the second communication line, wherein tis a second propagation delay over the second communication line, so that the upstream symbol with the second structure transmitted by the second remote communication unit arrives at the access node at the reference time point t.

Example embodiments describe a transmitter including data encapsulation circuitry configured to encapsulate data packets into Data Transport Units, DTUs, for further transmission over a communication medium. The data packets have respective Quality of Service, QoS, tolerances. The data encapsulation circuitry is configured to delay transmission of first data packets with a lower QoS tolerance and to group the first data packets in a subset of DTUs available for transportation of the first data packets.

Encapsulation of data packets

A communication system in which a constellation employing partially anti-symmetric amplitude labels is used to transmit probabilistically shaped amplitudes such that said amplitudes are also used to determine the signs applied thereto for transmission. In an example embodiment, a data transmitter is configured to use a suitable logic function (e.g., an XOR function) to place the parity generated by an FEC code into a selected amplitude bit while using the partially anti-symmetric amplitude labels to avoid placing the parity into the sign bits of the transmitted constellation symbols. In some embodiments, the FEC code can be a low-density parity-check code. Some embodiments are compatible with layered FEC coding, e.g., employing an outer FEC code and an inner FEC code. In some embodiments, FEC coding may be optional. Some embodiments can advantageously be used in communication systems relying on DMT modulation, such as the systems providing DSL access over copper wiring.

Transmission of probabilistically shaped amplitudes using partially anti-symmetric amplitude labels

An FDM communication system in which encoding/decoding settings for different sets of tones are specified using index values assigned to different sets of tones by selecting suitable respective values from a fixed set of index values. Each of the specified index values causes the corresponding digital signal processor to use a respective predefined pair of encoding or decoding settings that includes a respective predefined constellation and a respective predefined shaping code. In some embodiments, the used shaping codes are configured to operate as block codes, with the block sizes being selected such that a multi-code frame generated using multiple shaping codes can be matched to exactly one DMT symbol or to a desired number of whole DMT symbols.

Growing community of inventors

Kessel-lo, Belgium

Yannick Lefevre