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1.发明专利
公开(公告)号：JPH11340847A
公开(公告)日：1999-12-10
申请号：JP11528799
申请日：1999-04-22
Applicant: LUCENT TECHNOLOGIES INC
Inventor： CHEN BRIAN , CARL-ERIK WILHELM
Abstract: PROBLEM TO BE SOLVED: To reduce adjacent channel interference effectively in an adjacent area, in which an IBOC/CM system is used by making the power level of the sub-set of the digital modulation signal of the sub-band of a digital band lower than the power level of the second sub-set of the digital modulation signal of the second sub-band of the digital band. SOLUTION: An IBOC/AM system uses a digital band, using the analog host AM carrier wave with frequencies (fc) in 30 kHz width as a center. At the using of the IBOC/AM system in two adjacent regions to which the frequencies (fc) are assigned so as to be separated by 20 kHz, they mutually overlap by 10 kHz amount, and sub-adjacent channel interference is generated. In this case, a profile 301 is mounted in the region with the low frequencies (fc) among the two adjacent region mounts, and a profile 311 is mounted in the region with the high frequencies (fc). Thus, the profiles 301 and 311 do not overlap each other, and sub-adjacent channel interference can be prevented.
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公开(公告)号：JP2000196470A
公开(公告)日：2000-07-14
申请号：JP36198999
申请日：1999-12-21
Applicant: LUCENT TECHNOLOGIES INC
Inventor： CHEN BRIAN , SUNDBERG CARL-ERIK
Abstract: PROBLEM TO BE SOLVED: To provide satisfactory performance by selecting an optimum group composed of plural complementary punctured convolution codes and encoding the stream of information bits while using the code of the selected optimum group. SOLUTION: A convolution encoder 26 encodes the bit stream to the sequence of symbols while using a complementary punctured pair convolution(CPPC) code. An IBOC system is constituted so as to use the forward error correction code of rate 4/5 called semi-band code for both upper and lower wave band channels. By coupling these channels, the error correction code of rate 2/5 called full band code is formed. By puncturing the mother code of rate 1/3, the required conditions of an IBOC code can be satisfied. The code of rate 1/3 and limit length K=7 as the mother code of rate 1/3 has three generators g0=1011011, g1=1111001 and g2=1100101.
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公开(公告)号：JPH11284520A
公开(公告)日：1999-10-15
申请号：JP430999
申请日：1999-01-11
Applicant: LUCENT TECHNOLOGIES INC
Inventor： CHEN BRIAN , SUNDBERG CARL-ERIK WILHELM
Abstract: PROBLEM TO BE SOLVED: To obtain a punctured convolution code by which satisfactory performance is provided by encoding an information bit by using a group of codes including complementary codes whose values are not equivalent. SOLUTION: A digital bit stream from an audio encoder 25 is inputted in a convolutional code part 26. The bit stream is encoded to a symbol string, by the use of a pair of the complementary punctured convolutional codes by the convolutional code part 26. A rate 4/5 anterior error correcting code is used for both upper and lower side band channels in the convolutional code part 26. Namely, the codes of all bandwidth class I (rate 4/11) and a class II (rate 4/9) are generated by puncturing a rate 1/3 base code. An average rate between the classes I and II is 2/5. Half bandwidth codes (the lower side band code and the upper side band code) are generated by puncturing all the bandwidth codes. The average rate between the half band width code is 4/5.
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公开(公告)号：JPH10271085A
公开(公告)日：1998-10-09
申请号：JP6564698
申请日：1998-03-16
Applicant: LUCENT TECHNOLOGIES INC
Inventor： CHEN BRIAN , SUNDBERG CARL-ERIK WILHELM
Abstract: PROBLEM TO BE SOLVED: To increase the convenience of a simultaneous transmission system between an FM signal and a digital modulation carrier by selecting carriers inserted into an FM band in a specified order. SOLUTION: A module 116 analyzes the interference of emulated transmission while the pre-cancellation effect of the sub-set of the carriers to the FM signal is considered. The module 116 calculates the value of γaggregate , which is caused by the FM signal by the sub-set of the carriers and shows deterioration as a whole based on interference analysis. It is decided whether the value exceeds the value of γmax or not. When it does not exceed the value, the module 116 decides whether a pair of final carriers is added or not to the sub-set. In such a case, a control channel transmitting information identifying the selected pair of carriers to a receiver changes a pair of carriers selected by the module 116 at every frame. A data bit showing control information is generated by a control channel processor 119.
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公开(公告)号：CA2228240A1
公开(公告)日：1998-09-18
申请号：CA2228240
申请日：1998-01-30
Applicant: LUCENT TECHNOLOGIES INC
Inventor： CHEN BRIAN , SUNDBERG CARL-ERIK WILHELM
Abstract: In a system for simulcasting digitally modulated and analog FM signals over the same FM frequency band, the effect of the analog FM signal on the digitally modulated signal in the simulcast is calculated and canceled from the latter signal before its transmission. As a result, the digital transmission is free from interference from the analog FM signal. Moreover, the digital transmission is achieved by adaptively inserting a time varying number of carriers modulated by digital data into the FM band. The carriers are selected frame by frame to control their interference with the analog FM signal. In accordance with the invention, the carriers are selected in a predetermined order, and in a preferred embodiment grouped contiguously with one another in the FM band. As a result, the rate of control information required to identify the inserted carriers to a receiver is advantageously low.
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Patent Agency Ranking6.发明专利
公开(公告)号：CA2266114A1
公开(公告)日：1999-10-22
申请号：CA2266114
申请日：1999-03-17
Applicant: LUCENT TECHNOLOGIES INC
Inventor： CHEN BRIAN , SUNDBERG CARL-ERIK WILHELM
IPC: H04L27/00 , H04B1/04 , H04H20/00 , H04J11/00 , H04L5/02 , H04L27/36 , H04B3/06 , H04B7/005 , H04L27/04
Abstract: In a communications system implementing an in-band on channel AM (IBOC-AM) (also known as "hybrid IBOC-AM") scheme, digitally modulated signals are transmitted in a 30 kHz digital band centered at an analog host AM carrier frequency f c. The host AM carrier is assigned to the geographic area served by the communications system for AM radio broadcast. It is likely that a similar IBOC-AM scheme is implemented in an adjacent area which is assigned a second analog host AM carrier having a frequency which is either 20 kHz higher or lower than f c. In that case, the transmission of the digitally modulated signals are interfered by a similar transmission in the adjacent area. The interference is known as "second adjacent channel interference." To reduce such interference, selected power profiles in accordance with the invention are used to allocate the relative transmission power to the digitally modulated signals in the digital band.
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公开(公告)号：DE69841744D1
公开(公告)日：2010-08-12
申请号：DE69841744
申请日：1998-03-11
Applicant: LUCENT TECHNOLOGIES INC
Inventor： CHEN BRIAN , SUNDBERG CARL-ERIK WILHELM
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公开(公告)号：CA2228240C
公开(公告)日：2002-03-26
申请号：CA2228240
申请日：1998-01-30
Applicant: LUCENT TECHNOLOGIES INC
Inventor： SUNDBERG CARL-ERIK WILHELM , CHEN BRIAN
Abstract: In a system for simulcasting digitally modulated and analog FM signals over the same FM frequency band, the effect of the analog FM signal on the digitally modulated signal in the simulcast is calculated and canceled from the latter signal before its transmission. As a result, the digital transmission is free from interference from the analog FM signal. Moreover, the digital transmission is achieved by adaptively inserting a time varying number of carriers modulated by digital data into the FM band. The carriers are selected frame by frame to control their interference with the analog FM signal. In accordance with the invention, the carriers are selected in a predetermined order, and in a preferred embodiment grouped contiguously with one another in the FM band. As a result, the rate of control information required to identify the inserted carriers to a receiver is advantageously low.
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公开(公告)号：DE69933256T2
公开(公告)日：2007-04-05
申请号：DE69933256
申请日：1999-04-13
Applicant: LUCENT TECHNOLOGIES INC
Inventor： CHEN BRIAN , SUNDBERG CARL-ERIK WILHELM
IPC: H04L5/02 , H04B1/04 , H04L27/00 , H04B7/005 , H04H20/00 , H04J11/00 , H04L27/26 , H04L27/36 , H04M11/06
Abstract: In a communications system implementing an in-band on channel AM (IBOC-AM) (also known as "hybrid IBOC-AM") scheme, digitally modulated signals are transmitted in a 30 kHz digital band centered at an analog host AM carrier frequency fc. The host AM carrier is assigned to the geographic area served by the communications system for AM radio broadcast. It is likely that a similar IBOC-AM scheme is implemented in an adjacent area which is assigned a second analog host AM carrier having a frequency which is either 20 kHz higher or lower than fc. In that case, the transmission of the digitally modulated signals are interfered by a similar transmission in the adjacent area. The interference is known as "second adjacent channel interference." To reduce such interference, selected power profiles in accordance with the invention are used to allocate the relative transmission power to the digitally modulated signals in the digital band.
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10.发明专利
公开(公告)号：CA2266114C
公开(公告)日：2002-08-20
申请号：CA2266114
申请日：1999-03-17
Applicant: LUCENT TECHNOLOGIES INC
Inventor： SUNDBERG CARL-ERIK WILHELM , CHEN BRIAN
IPC: H04L27/00 , H04B1/04 , H04H20/00 , H04J11/00 , H04L5/02 , H04L27/36 , H04B3/06 , H04B7/005 , H04L27/04
Abstract: In a communications system implementing an in-band on channel AM (IBOC-AM) (also known as "hybrid IBOC-AM") scheme, digitally modulated signals are transmitted in a 30 kHz digital band centered at an analog host AM carrier frequency f c. The host AM carrier is assigned to the geographic area served by the communications system for AM radio broadcast. It is likely that a similar IBOC-AM scheme is implemented in an adjacent area which is assigned a second analog host AM carrier having a frequency which is either 20 kHz higher or lower than f c. In that case, the transmission of the digitally modulated signals are interfered by a similar transmission in the adjacent area. The interference is known as "second adjacent channel interference." To reduce such interference, selected power profiles in accordance with the invention are used to allocate the relative transmission power to the digitally modulated signals in the digital band.
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