US 9,253,428 Broadcasting system with digital television signals and metadata that modulate respective sets of OFDM carriers

1. A method for generating coded orthogonal frequency division multiplex (COFDM) digital television signals suitable for broadcasting, said method comprising steps of: generating a serial stream of effective orthogonal frequency division multiplex (OFDM) symbol blocks conveying one or more digital television signals; generating a baseband metadata signal descriptive of the processes for generating said serial stream of effective OFDM symbol blocks; generating a serial stream of complete OFDM symbol blocks from said serial stream of effective OFDM symbol blocks by substeps including introducing segments of said baseband metadata signal into said serial stream of complete OFDM symbol blocks and introducing descriptions of pilot carrier into said serial stream of complete OFDM symbol blocks for the purpose of facilitating frequency-domain channel equalization in receivers of said COFDM digital television signals; modulating a plurality of orthogonal frequency-division-multiplexed carriers in accordance with said serial stream of complete OFDM symbol blocks, thus generating a COFDM signal; and inserting a guard interval and cyclic prefix into said COFDM signal.

9. Receiver apparatus for receiving a selected one of coded orthogonal frequency division multiplex (COFDM) digital signals each conveying a respective baseband data signal and a respective baseband metadata signal descriptive of the processes for generating its said respective baseband data signal, each said baseband metadata signal including a Zadoff-Chu sequence and at least one pseudo-random sequence scrambled per that Zadoff-Chu sequence, which said Zadoff-Chu sequences are repeated from time to time, said Zadoff-Chu sequences indicative of the standard governing the transmission of said selected COFDM signal and the phasing of said repetitive pseudo-random sequences indicative of the processes for baseband data signal in accordance with said standard, said receiver apparatus configured for utilizing said baseband metadata signal to control its processing of said baseband data signal, and said receiver apparatus comprising: a front-end tuner for converting a selected radio-frequency analog COFDM signal to a digitized baseband COFDM signal; a discrete-Fourier-transform computer for computing selected sizes of discrete Fourier transform (DFT) of said digitized baseband COFDM signal, said DFT computer configured for supplying a first set of complex coordinates descriptive of respective quadrature-amplitude-modulated (QAM) orthogonal frequency-division multiplexed (OFDM) carrier waves which convey said respective baseband data signal and are of respective frequencies ranging from the lowest to highest frequencies in said baseband, said DFT computer further configured for supplying a second set of complex coordinates descriptive of respective OFDM carrier waves which convey said respective baseband metadata signal and are of respective midband frequencies in said baseband, said DFT computer further configured for supplying a third set of complex coordinates descriptive of respective OFDM pilot carrier waves intermingled in accordance with a specified pattern among said OFDM carrier waves which convey said respective baseband data signal; a guard-interval-remover unit connected for removing guard-interval digital samples including samples of cyclic prefixes from said digitized baseband COFDM signal to generate OFDM signal for application to said DFT computer as an input signal thereto; timing synchronization apparatus for synchronizing the computation of components of said DFT with said OFDM carrier waves, connected for supplying respective control signals to said guard-interval-remover unit and to said DFT computer; a frequency-domain channel equalizer for equalizing said first and second sets of complex samples of OFDM carrier waves supplied from said DFT computer, said equalizing being performed responsive to said third set of set of complex coordinates supplied from said DFT computer; a bank of parallel-to-serial converters configured for converting said second set of complex coordinates describing said second set of OFDM carrier waves in the midband frequencies of said baseband COFDM signal to different respective serial sequences of complex coordinates; a standard-determination unit for detecting which one if any of said different serial sequences of complex coordinates convey Zadoff-Chu sequences that specify said standard governing the transmission of said selected COFDM signal; and apparatus for processing said first set of complex coordinates describing QAM of OFDM carrier waves conveying baseband data signal, as supplied from said frequency-domain channel equalizer, said processing being in accordance with said standard governing the transmission of said selected COFDM signal as specified by said standard-determination unit.

11. Receiver apparatus for receiving a selected one of coded orthogonal frequency division multiplex (COFDM) digital signals each conveying a respective baseband data signal and a respective baseband metadata signal descriptive of the processes for generating its said respective baseband data signal, each said baseband metadata signal including a Zadoff-Chu sequence and at least one pseudo-random sequence scrambled per that Zadoff-Chu sequence, which said Zadoff-Chu sequences are repeated from time to time, said Zadoff-Chu sequences indicative of the standard governing the transmission of said selected COFDM signal and the phasing of said repetitive pseudo-random sequences indicative of the processes for baseband data signal in accordance with said standard, said receiver apparatus configured for utilizing said baseband metadata signal to control its processing of said baseband data signal, and said receiver apparatus comprising: a front-end tuner for converting a selected radio-frequency analog COFDM signal to a digitized baseband COFDM signal; a discrete-Fourier-transform computer for computing selected sizes of discrete Fourier transform (DFT) of said digitized baseband COFDM signal, said DFT computer configured for supplying a first set of complex coordinates descriptive of respective quadrature-amplitude-modulated (QAM) orthogonal frequency-division multiplexed (OFDM) carrier waves which convey said respective baseband data signal and are of respective frequencies ranging from the lowest to highest frequencies in said baseband, said DFT computer further configured for supplying a second set of complex coordinates descriptive of respective OFDM carrier waves which convey said respective baseband metadata signal and are of respective midband frequencies in said baseband, said DFT computer further configured for supplying a third set of complex coordinates descriptive of respective OFDM pilot carrier waves intermingled in accordance with a specified pattern among said OFDM carrier waves which convey said respective baseband data signal; a guard-interval-remover unit connected for removing guard-interval digital samples including samples of cyclic prefixes from said digitized baseband COFDM signal to generate OFDM signal for application to said DFT computer as an input signal thereto; timing synchronization apparatus for synchronizing the computation of components of said DFT with said OFDM carrier waves, connected for supplying respective control signals to said guard-interval-remover unit and to said DFT computer; a frequency-domain channel equalizer for equalizing said first and second sets of complex samples of OFDM carrier waves supplied from said DFT computer, said equalizing being performed responsive to said third set of set of complex coordinates supplied from said DFT computer; a bank of parallel-to-serial converters each configured for deshuffling said first set of complex coordinates describing said set of OFDM carrier waves of said baseband COFDM signal in accordance with a respective transmission standard, one of which bank of parallel-to-serial converters is selected for supplying de-shuffled said complex coordinates describing said first set of OFDM carrier waves; means for demapping and de-interleaving said de-shuffled complex coordinates describing said first set of OFDM carrier waves to recover de-interleaved soft bits of cells of forward-error-correction coding of said respective baseband data signal; a bank of decoders for said forward-error-correction coding of said respective baseband data signal, each for a respective sort of forward-error-correction coding, said bank of decoders configured so a selected one of them is connected for decoding said de-interleaved soft bits of cells of forward-error-correction coding of said respective baseband data signal to reproduce said respective baseband data signal; a further QAM de-mapper configured for de-mapping said complex coordinates describing said second set of OFDM carrier waves to reproduce said respective baseband metadata signal; and a controller connected for responding to reproduced said respective baseband metadata signal for generating a plurality of control signals to control various operations in said receiver apparatus.

27. Receiver apparatus for receiving a selected one of a plurality of different types of coded orthogonal frequency division multiplex (COFDM) digital signals, at least some of which COFDM digital signals convey digital television information, each COFDM signal conveying a respective baseband data signal and a respective baseband metadata signal descriptive of processes used by a preceding transmitter for generating said respective baseband data signal, said receiver apparatus configured for processing the respective baseband data signal of each different type of COFDM digital signal selected for reception in accordance with said respective baseband metadata signal descriptive of the processes for generating that said respective baseband data signal, said processing of baseband data signals being controlled by control signals supplied from a controller in said receiver apparatus which controller generates said control signals responsive to said baseband metadata signals, said receiver apparatus characterized by: an improvement enabling said controller to utilize baseband metadata signals each including repeated pseudo-random binary sequences scrambled per a Zadoff-Chu sequence, said Zadoff-Chu sequence being used to provide said controller in said receiver apparatus—an indication of the particular standard governing transmission of said selected COFDM signal, and the phasing of said repeated pseudo-random sequences being used to provide said controller in said receiver apparatus—further indications of the particular processes said receiver apparatus is to perform in order to recover said baseband data signal in accordance with that said particular standard.