Abstract:
A coding and modulation apparatus and method are presented. The apparatus (10) comprises an encoder (11) that encodes input data into cell words, and a modulator (12) that modulates said cell words into constellation values of a non-uniform constellation. The modulator (12) is configured to use, based on the total number M of constellation points of the constellation and the signal-to-noise ratio SNR in dB, a non-uniform constellation from a group of constellations comprising one or more of predetermined constellations defined by the constellation position vector w0 . . . b−1, wherein b=M/4.
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 groupsof constellations each comprising one or more constellations.
Abstract:
A coding and modulation apparatus and method are presented. The apparatus (10) comprises an encoder (11) that encodes input data into cell words, and a modulator (12) that modulates said cell words into constellation values of a non-uniform constellation. The modulator (12) is configured to use, based on the total number M of constellation points of the constellation and the signal-to-noise ratio SNR in dB, a non-uniform constellation from a group of constellations comprising one or more of predetermined constellations defined by the constellation position vector w0 . . . b-1, wherein b=M/4.
Abstract:
An OFDM encoding apparatus for encoding OFDM symbols into an OFDM signal includes: a pre-distortion unit that pre-distorts OFDM symbols into pre-distorted OFDM symbols, the OFDM symbols including payload data and each being carried on multiple OFDM subcarriers; an OFDM generator that generates an OFDM signal from the pre-distorted OFDM symbols by OFDM modulating the pre-distorted OFDM symbols; and a filter that filters the OFDM signal to obtain a filtered OFDM signal, the filter being configured to attenuate the spectrum of the OFDM signal in frequency bands outside the signal bandwidth of the OFDM signal by applying a filter transfer function to the OFDM signal. The pre-distortion unit is configured to apply a pre-distortion transfer function equal to the inverse of the filter transfer function to the OFDM symbols.
Abstract:
A receiver for receiving data in a broadcast system comprises a broadcast receiver configured to receive, via said broadcast system, a receiver input data stream comprising a plurality of channel symbols represented by constellation points in a constellation diagram. A demodulator demodulates said channel symbols into codewords and a decoder decodes said codewords into output data words. A redundancy unit selects or requests, if demodulation of a channel symbol and/or decoding of a codeword is erroneous or likely to fail, redundancy data for demodulation of future channel symbols and/or decoding of future codewords via a broadband system and a broadband receiver obtains said redundancy data via said broadband system. Said demodulator and/or said decoder is configured to use the obtained redundancy data to demodulate the respective future channel symbols and to decode the respective future codewords, respectively.
Abstract:
A receiver for receiving data in a broadcast system includes a broadcast receiver configured to receive, via the broadcast system, a receiver input data stream including a plurality of channel symbols represented by constellation points in a constellation diagram. A demodulator demodulates the channel symbols into codewords and a decoder decodes the codewords into output data words. A redundancy unit selects or requests, if demodulation of a channel symbol and/or decoding of a codeword is erroneous or likely to fail, redundancy data for demodulation of future channel symbols and/or decoding of future codewords via a broadband system and a broadband receiver obtains the redundancy data via the broadband system. The demodulator and/or the decoder is configured to use the obtained redundancy data to demodulate the respective future channel symbols and to decode the respective future codewords, respectively.
Abstract:
A transmitter for transmitting payload data and emergency information using data symbols in a single-carrier or multi-carrier broadcast system includes a modulator configured to modulate one or more transmission symbols with signaling data for use in detecting and recovering the payload data at a receiver and to modulate one or more transmission symbols with the payload data. An emergency information receiver receives emergency information carrying information of an actual emergency. An emergency information embedder embeds emergency information into one or more transmission symbols, wherein the emergency information is embedded within a predetermined time period after its reception by using a resource used for carrying signaling data and/or payload data if no emergency information shall be transmitted. A transmission unit transmits the transmission symbols.
Abstract:
A coding and modulation apparatus and method are presented. The apparatus (10) comprises an encoder (11) that encodes input data into cell words, and a modulator (12) that modulates said cell words into constellation values of a non-uniform constellation. The modulator (12) is configured to use, based on the total number M of constellation points of the constellation and the signal-to-noise ratio SNR in dB, a non-uniform constellation from a group of constellations comprising one or more constellations defined by a constellation position vector comprising a predetermined number of constellation positions, wherein in one or more constellation position vectors two or more constellation positions are identical resulting from a condensation of preliminary constellation positions optimized before.
Abstract:
A transmitter transmits payload data using Orthogonal Frequency Division Multiplexed (OFDM) symbols. The transmitter comprises a frame builder configured to receive the payload data to be transmitted and to receive first signalling data for use in detecting and recovering the payload data at a receiver, and to form the payload data and the first signalling data into frames for transmission, the first signalling data forming a part of the frames with the payload data. A modulator is configured to modulate a first OFDM symbol with the first signalling data and to modulate one or more second OFDM symbols with the payload data. A signature sequence processor provides a signature sequence, a combiner combines the signature sequence with the first OFDM symbol, and a transmission unit transmits the first and second OFDM symbols. The signature sequence provided by the signature sequence processor comprises at least one of a first synchronisation sequence or a second message sequence, the first synchronisation sequence and/or the second message sequence being combined by the combiner with the first OFMD symbol. The first synchronisation sequence is provided for a receiver to detect and to recover the first signalling data from the first OFDM symbol and the second message sequence provides message information to the receiver. The message information may be used to convey a specific message to a user such as an emergency warning relating to a natural disaster such as an earthquake or a tsunami warning.