公开(公告)号：EP1155521B1

公开(公告)日：2005-11-02

申请号：EP00908706.5

申请日：2000-02-17

申请人： IBIQUITY DIGITAL CORPORATION

发明人： KROEGER, Brian, William

IPC分类号： H04H1/00

CPC分类号： H04H20/30 ,  H04H60/11 ,  H04H2201/20

摘要： A method is provided for processing a composite digital audio broadcast signal to mitigate intermittent interruptions in the reception of said digital audio broadcast signal. The method includes the steps of separating an analog modulated portion of the digital audio broadcast signal from a digitally modulated portion of the digital audio broadcast signal, producing a first plurality of audio frames having symbols representative of the analog modulated portion of the digital audio broadcast signal, and producing a second plurality of audio frames having symbols representative of the digitally modulated portion of the digital audio broadcast signal. The first plurality of audio frames is then combined with the second plurality of audio frames to produce a blended audio output. A method is also provided for transmitting a composite digital audio broadcast signal having an analog portion and a digital portion to mitigate intermittent interruptions in the reception of said digital audio broadcast signal. The method comprises the steps of arranging symbols representative of the digital portion of the digital audio broadcast signal into a plurality of audio frames, producing a plurality of modem frames, each of the modem frames including a predetermined number of the audio frames, and adding a frame synchronization signal to each of the modem frames. The modem frames are then transmitted along with the analog portion of the digital audio broadcast signal, with the analog portion being delayed by a time delay corresponding to an integral number of the modem frames. The invention also encompasses radio receivers and transmitters which process signals according to the above method.

公开(公告)号：EP1206866A1

公开(公告)日：2002-05-22

申请号：EP00957735.4

申请日：2000-08-23

申请人： IBIQUITY DIGITAL CORPORATION

发明人： SHASTRI, Anjali ,  KROEGER, Brian, William

IPC分类号： H04L27/26

CPC分类号： H04L27/2624

摘要： This invention provides a method for reducing peak to average power ratio in a radio frequency signal. The method comprises the steps of modulating a plurality of subcarriers with a plurality of data symbol vectors to produce a first modulated signal; limiting the magnitude of the first modulated signal to produce a first limited modulated signal; demodulating the first limited modulated signal to recover the constellation points; predistorting the data symbol vectors to provide a minimum magnitude for in-phase and quadrature components thereof to produce predistorted data symbol vectors; modulating the plurality of carriers with the predistorted data symbol vectors to produce a second modulated signal; limiting the magnitude the second modulated signal to produce a second limited modulated signal; and reducing intermodulation products in the second limited modulated signal. Transmitters that perform the method are also included.

公开(公告)号：EP1712051B9

公开(公告)日：2010-02-03

申请号：EP05705538.6

申请日：2005-01-12

申请人： IBIQUITY DIGITAL CORPORATION

发明人： KROEGER, Brian, William

IPC分类号： H04L27/26

CPC分类号： H04L27/2623 ,  H04L27/2624 ,  H04L27/2626

公开(公告)号：EP1712051A1

公开(公告)日：2006-10-18

申请号：EP05705538.6

申请日：2005-01-12

申请人： IBIQUITY DIGITAL CORPORATION

发明人： KROEGER, Brian, William

IPC分类号： H04L27/26

CPC分类号： H04L27/2623 ,  H04L27/2624 ,  H04L27/2626

摘要： A method of reducing peak-to-average power ratio in an OFDM signal comprises the steps of modulating a set of subcarriers with a set of data symbol vectors to produce a first modulated signal, limiting the magnitude of the first modulated signal to produce a first limited modulated signal, demodulating the first limited modulated signal to recover distorted input symbol vectors, constraining the distorted input symbol vectors to values greater than or equal to a minimum threshold value to produce constrained data symbol vectors, constraining out-of-band spectral components to lie within a predetermined mask, and remodulating the constrained data symbol vectors. A transmitter that performs the method is also included.

公开(公告)号：EP1125384B1

公开(公告)日：2004-09-22

申请号：EP99965739.8

申请日：1999-10-28

申请人： IBIQUITY DIGITAL CORPORATION

发明人： KROEGER, Brian, William ,  BAIRD, Jeffrey, Scott

IPC分类号： H04H1/00 ,  H04B1/10

CPC分类号： H04B1/109 ,  H04H40/27 ,  H04H2201/183 ,  H04L25/03006

公开(公告)号：EP1293055B1

公开(公告)日：2004-09-15

申请号：EP01939750.4

申请日：2001-05-31

申请人： IBIQUITY DIGITAL CORPORATION

发明人： KROEGER, Brian, William ,  BAIRD, Jeffrey, S.

IPC分类号： H04H1/00

CPC分类号： H04L27/2647 ,  H03D3/007 ,  H04H20/30 ,  H04H2201/183 ,  H04H2201/20

公开(公告)号：EP1293055A2

公开(公告)日：2003-03-19

申请号：EP01939750.4

申请日：2001-05-31

申请人： IBIQUITY DIGITAL CORPORATION

发明人： KROEGER, Brian, William ,  BAIRD, Jeffrey, S.

IPC分类号： H04H1/00

CPC分类号： H04L27/2647 ,  H03D3/007 ,  H04H20/30 ,  H04H2201/183 ,  H04H2201/20

摘要： This invention provides a method for reducing radio frequency interference in an FM in-band on-channel digital audio broadcasting receiver. The method comprises the steps of receiving a composite signal including a signal of interest and an interfering signal, demodulating the composite signal to produce a first demodulated signal, computing a first binary soft decision from the first demodulated signal, processing the composite signal to produce a processed signal, demodulating the processed signal to produce a second demodulated signal, computing a second binary soft decision from the second demodulated signal, and combining the first and second binary soft decisions to produce an output signal. Radio receivers that utilize the above method are also included.

公开(公告)号：EP1232591A1

公开(公告)日：2002-08-21

申请号：EP00993065.2

申请日：2000-11-10

申请人： IBIQUITY DIGITAL CORPORATION

发明人： KROEGER, Brian, William ,  BAIRD, Jeffrey, S.

IPC分类号： H04H1/00

CPC分类号： H04L27/2613 ,  H04H20/30 ,  H04H2201/183 ,  H04H2201/20 ,  H04L1/004 ,  H04L5/0048 ,  H04L25/0226 ,  H04L25/0228 ,  H04L25/03159 ,  H04L27/2071 ,  H04L27/2655

摘要： A method for transmission of data in a digital audio broadcasting system includes the steps of providing a plurality of orthogonal frequency division multiplexed sub-carriers, with the sub-carriers including data sub-carriers and reference sub-carriers, and modulating the data sub-carriers with a digital signal representative of information to be transmitted. The reference sub-carriers are modulated with a sequence of timing bits, wherein the sequence of timing bits includes an unambiguous block synchronization word, and the number of bits comprising the block synchronization word is less than one half of the number of bits in said timing sequence. Then the orthogonal frequency division multiplexed sub-carriers are transmitted. Receivers that differentially detect the block synchronization word and use the block synchronization word to coherently detect the digital signal representative of information to be transmitted are also included.