Abstract:
A coding and modulation apparatus and method are presented, particularly for use in a system according to IEEE 802.11. The apparatus comprises an encoder configured to encode input data into cell words according to a low density parity check code, LDPC, and a modulator configured to modulate said cell words into constellation values of a non-uniform constellation and to assign bit combinations to constellation values of the used non-uniform constellation, wherein said modulator is configured to use, based on the PHY mode, the total number M of constellation points of the constellation and the code rate, a particular non-uniform constellation.
Abstract:
A method for transmitting signals over a power line network, wherein within the power line network at least one transmitter and at least one receiver communicate via at least two channels, each channel including a respective feeding port of at least one transmitter and the respective receiving port of the at least one transmitter and transmitter including at least two feeding ports. The method: determines a channel characteristic of each of the channels; applies a feeding port selection criterion based on the channel characteristic; and selects an excluded feeding port among the at least two feeding ports based on the feeding port selection criterion, wherein the excluded feeding port is not used during further communication. A corresponding power line communication modem can implement the method.
Abstract:
The present invention relates to OFDM generation apparatus and methods for generating OFDM transmission signals from OFDM symbols, each comprising a plurality of OFDM subcarriers, for transmission in a multi-carrier data transmission system. An embodiment of the proposed apparatus and method are adapted for using a selected mixing frequency for mixing said complex time-domain samples of said OFDM symbol from a baseband frequency up to a passband frequency by use of a mixing frequency to obtain said OFDM transmission signal, wherein the mixing frequency is selected such that common phase rotations of the OFDM subcarriers of said OFDM symbol with respect to adjacent OFDM symbols of said OFDM transmission signal are avoided or compensated after said mixing. Further embodiments for avoidance or compensation of such common phase rotations are provided.
Abstract:
A receiver for receiving data in a broadcast system includes a broadcast receiver that receives via the broadcast system a receiver input data stream including plural channel symbols represented by constellation points in a constellation diagram, a demodulator that demodulates the channel symbols into codewords, and a decoder that decodes the codewords into output data words. A redundancy calculator determines a required amount of redundancy data required for correct demodulation and decoding by use of the originally received channel symbol and additional redundancy data. A broadband request unit requests, if demodulation of a channel symbol and/or decoding of a codeword is erroneous or likely to fail, a required amount of redundancy data via a broadband system, that is received by a broadband receiver via said broadband system. The demodulator and/or the decoder is configured to use the redundancy data for demodulation and decoding, respectively.
Abstract:
A receiver receives payload data transmitted on a downstream using Orthogonal Frequency Division Multiplexed (OFDM) symbols via a cable network. The receiver includes circuitry configured to receive a downstream signal representing the payload data modulated onto one or more OFDM symbols, and to demodulate the OFDM symbols of each frame to detect and to recover the payload data using the physical layer signalling data. One or more of the frames of the received signal includes a preamble of the frame providing the physical layer signalling data, and in a separate media access control (MAC) signal within the frame, upstream messages relating to the transmission of data from the receiver to the transmitter. Accordingly, an arrangement is provided for a cable network communications system in which a capacity for upstream signalling messages for communicating on the downstream can be adapted to a requirement of receivers connected to the network.
Abstract:
A method for transmitting a signal from a transmitter over a channel to a receiver on a Power Line Network, wherein said signal is OFDM-modulated on a set of sub-carriers, is proposed, wherein an OFDM tonemap and an eigenbeamforming encoding matrix are determined based on a channel estimation for each sub-carrier, a tonemap feedback signal and an eigenbeamforming feedback signal are generated, which are descriptive of said OFDM tonemap and said eigenbeamforming encoding matrix, respectively, and transmitted to the transmitter. A corresponding receiver, a transmitter, a power line communication and a power line communication system are described as well.
Abstract:
A coding and modulation apparatus and method are presented. The apparatus comprises an encoder that encodes input data into cell words, and a modulator that modulates said cell words into constellation values of a non-uniform constellation. The modulator is configured to use, based on the total number M of constellation points of the constellation and the code rate, a non-uniform constellation from one or several groups of constellations each comprising one or more constellations.
Abstract:
A transmitting device, a receiving device, and a communication method for transmitting and receiving data modulated on frequency subcarriers of an OFDM communication system. An OFDM burst includes a preamble part and payload data part, whereby the preamble includes a section of pilot symbols mapped onto every n-th frequency subcarrier and signaling data mapped onto the frequency subcarriers between the frequency subcarriers with the pilot symbols. A first channel estimation on the basis of the received pilot symbols is performed, the result of which is used to reconstruct the entire section of the received preamble as a training pattern for an accurate channel estimation, which is used for a channel equalization of the received payload part.
Abstract:
A coding and modulation apparatus and method are presented, particularly for use in a system according to IEEE 802.11. The apparatus comprises an encoder configured to encode input data into cell words according to a low density parity check code, LDPC, and a modulator configured to modulate said cell words into constellation values of a non-uniform constellation and to assign bit combinations to constellation values of the used non-uniform constellation, wherein said modulator is configured to use, based on the PHY mode, the total number M of constellation points of the constellation and the code rate, a particular non-uniform constellation.
Abstract:
A coding and modulation apparatus and method are presented, particularly for use in a system according to IEEE 802.11. The apparatus comprises an encoder configured to encode input data into cell words according to a binary convolutional code, BCC, or a low density parity check code, LDPC, and a modulator configured to modulate said cell words into constellation values of a non-uniform constellation and to assign bit combinations to constellation values of the used non-uniform constellation, wherein said modulator is configured to use, based on the code used by the encoder, the total number M of constellation points of the constellation and the code rate.