公开(公告)号：DE69933256D1

公开(公告)日：2006-11-02

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.

公开(公告)号：CA2289344C

公开(公告)日：2005-06-28

申请号：CA2289344

申请日：1999-11-10

Applicant: LUCENT TECHNOLOGIES INC

Inventor： CHEN BRIAN ,  SUNDBERG CARL-ERIK WILHELM

IPC: H03M13/00 ,  H03M13/23 ,  H03M13/41 ,  H04L1/00 ,  H04L27/26 ,  H03M13/31

Abstract: The invention provides optimal complementary punctured convolutional codes f or coding information bits in a communication system. In an illustrative embodiment, an optimal pair of complementary punctured codes is selected from a set of potential code pairs. The set of potential code pairs includes all non-catastrophic complementary punctured code pairs which combine to produce to a specified full-bandwidth code, and thus includes both equivalent and non-equivalent complementary codes. The optimal code pair may be selected, for example, as the pair of equivalent or non-equivalent codes which has the best free Hamming distance and minimum information error weight of all t he pairs in the set. In addition, the invention provides both rate-compatible and rate- incompatible codes suitable for use in providing unequal error protection (UEP) for different classes of information bits. The invention further provides optimal bit assignment techniques for use in digital audio broadcasting or other applications in which digital information is transmitted on subcarriers in both an upper and a lower sideband of an analog carrier.

公开(公告)号：CA2289344A1

公开(公告)日：2000-06-21

申请号：CA2289344

申请日：1999-11-10

Applicant: LUCENT TECHNOLOGIES INC

Inventor： SUNDBERG CARL-ERIK WILHELM ,  CHEN BRIAN

IPC: H03M13/00 ,  H03M13/23 ,  H03M13/41 ,  H04L1/00 ,  H04L27/26 ,  H03M13/31

Abstract: The invention provides optimal complementary punctured convolutional codes for coding information bits in a communication system. In an illustrative embodiment, an optimal pair of complementary punctured codes is selected from a set of potential code pairs. The set of potential code pairs includes all non-catastrophic complementary punctured code pairs which combine to produce to a specified full-bandwidth code, and thus includes both equivalent and non-equivalent complementary codes. The optimal code pair may be selected, for example, as the pair of equivalent or non-equivalent codes which has the best free Hamming distance and minimum information error weight of all the pairs in the set. In addition, the invention provides both rate-compatible and rateincompatible codes suitable for use in providing unequal error protection (UEP) for different classes of information bits. The invention further provides optimal bit assignment techniques for use in digital audio broadcasting or other applications in which digital information is transmitted on subcarriers in both an upper and a lower sideband of an analog carrier.