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公开(公告)号：BR0101646A
公开(公告)日：2001-12-26
申请号：BR0101646
申请日：2001-04-30
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LI XIAODONG , PAPADIAS CONSTANTINOS B , VISWANATHAN HARISH
Abstract: Wireless communications for frequency-selective fading channels is realized by employing a system including orthogonal frequency division multiplexing (OFDM) in combination with an at least two antenna transmit diversity arrangement. Specifically, OFDM converts a multipath channel into a plurality of narrowband subchannels each having flat fading. Then, the signals on the same frequency subchannels of the at least two antennas are grouped together. Considering a first frequency subchannel, during a first OFDM time interval, a first signal and a second signal are transmitted on the first frequency subchannel from a first antenna (0) and from a second antenna (1), respectively. During a second OFDM time interval, a reverse sign (-) complex conjugate of the second signal and a complex conjugate of the first signal are transmitted from the first antenna and the second antenna, respectively. In a specific embodiment of the invention, reduced complexity in the implementation is realized by a reverse order complex conjugate and a reverse order, reverse sign (-) complex conjugate and judicious selection of the processed data signals in order to transmit the appropriate ones of the signals during the first and second OFDM intervals. Again, if the channel remains constant over the two OFDM intervals, diversity combination is realized for each frequency subchannel. In another embodiment of the invention, antenna-group hopping is employed in conjunction with pairing in time of the OFDM frequency subchannel signals to realize increased transmit diversity without rate loss.
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公开(公告)号：CA2313818A1
公开(公告)日：2001-01-27
申请号：CA2313818
申请日：2000-07-12
Applicant: LUCENT TECHNOLOGIES INC
Inventor： RUPP MARKUS , NARAYANASWAMY SHANKAR , LI XIAODONG , KRISHNAMOORTHY RAJEEV , VISWANATHAN HARISH
Abstract: In a wireless communication system, the constellation mapping scheme employ ed may be changed on a per-time-slot basis, i.e., from time slot to time slot, so that the constellation used to encode the symbols of each time slot may be different for each time slot within a single frame and may be different for a particular time slot i n different consecutive frames. In other words, several constellation mapping schemes ar e available, with each providing the ability to transmit a different number of bits per symbol, and the particular constellation mapping scheme employed for any time slot need be selected for that time slot only. The ability to use any particular constellation mapping scheme is dependent on the current channel quality. The particular constellation mappi ng used for the user data of the time slot may be indicated in the preamble of the time slot. To this end, each time slot may have its own preamble that is mapped with a constellation mapping scheme which is a) known à priori, b) may be the same for all time slots, and c) may be different from the constellation mapping scheme used to encode user data in the time slot. A receiver can determine the constellation mapping used for each time slot from solely from the preamble of the time slot.
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公开(公告)号：CA2313818C
公开(公告)日：2007-07-10
申请号：CA2313818
申请日：2000-07-12
Applicant: LUCENT TECHNOLOGIES INC
Inventor： VISWANATHAN HARISH , RUPP MARKUS , NARAYANASWAMY SHANKAR , KRISHNAMOORTHY RAJEEV , LI XIAODONG
Abstract: In a wireless communication system, the constellation mapping scheme employe d may be changed on a per-time-slot basis, i.e., from time slot to time slot, so that the constellation used to encode the symbols of each time slot may be different for each time slot within a single frame and may be different for a particular time slot i n different consecutive frames. In other words, several constellation mapping schemes ar e available, with each providing the ability to transmit a different number of bits per symbol, and the particular constellation mapping scheme employed for any time slot need be selected for that time slot only. The ability to use any particular constellation mapping scheme is dependent on the current channel quality. The particular constellation mappi ng used for the user data of the time slot may be indicated in the preamble of the time slot. To this end, each time slot may have its own preamble that is mapped with a constellation mapping scheme which is a) known à priori, b) may be the same for all time slots, and c) may be different from the constellation mapping scheme used to encode user data in the time slot. A receiver can determine the constellation mapping used for each time slot from solely from the preamble of the time slot.
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公开(公告)号：DE60014798T2
公开(公告)日：2005-06-09
申请号：DE60014798
申请日：2000-07-17
Applicant: LUCENT TECHNOLOGIES INC
Inventor： KRISHNAMOORTHY RAJEEV , LI XIAODONG , NARAYANASWAMY SHANKAR , RUPP MARKUS , VISWANATHAN HARISH
Abstract: In a wireless communication system, the constellation mapping scheme employed may be changed on a per-time-slot basis, i.e., from time slot to time slot, so that the constellation used to encode the symbols of each time slot may be different for each time slot within a single frame and may be different for a particular time slot in different consecutive frames. In other words, several constellation mapping schemes are available, with each providing the ability to transmit a different number of bits per symbol, and the particular constellation mapping scheme employed for any time slot need be selected for that time slot only. The ability to use any particular constellation mapping scheme is dependent on the current channel quality. The particular constellation mapping used for the user data of the time slot may be indicated in the preamble of the time slot. To this end, each time slot may have its own preamble that is mapped with a constellation mapping scheme which is a) known Ù priori, b) may be the same for all time slots, and c) may be different from the constellation mapping scheme used to encode user data in the time slot. A receiver can determine the constellation mapping used for each time slot from solely from the preamble of the time slot.
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公开(公告)号：DE60014798D1
公开(公告)日：2004-11-18
申请号：DE60014798
申请日：2000-07-17
Applicant: LUCENT TECHNOLOGIES INC
Inventor： KRISHNAMOORTHY RAJEEV , LI XIAODONG , NARAYANASWAMY SHANKAR , RUPP MARKUS , VISWANATHAN HARISH
Abstract: In a wireless communication system, the constellation mapping scheme employed may be changed on a per-time-slot basis, i.e., from time slot to time slot, so that the constellation used to encode the symbols of each time slot may be different for each time slot within a single frame and may be different for a particular time slot in different consecutive frames. In other words, several constellation mapping schemes are available, with each providing the ability to transmit a different number of bits per symbol, and the particular constellation mapping scheme employed for any time slot need be selected for that time slot only. The ability to use any particular constellation mapping scheme is dependent on the current channel quality. The particular constellation mapping used for the user data of the time slot may be indicated in the preamble of the time slot. To this end, each time slot may have its own preamble that is mapped with a constellation mapping scheme which is a) known Ù priori, b) may be the same for all time slots, and c) may be different from the constellation mapping scheme used to encode user data in the time slot. A receiver can determine the constellation mapping used for each time slot from solely from the preamble of the time slot.
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Patent Agency Ranking
公开(公告)号：BR0002917A
公开(公告)日：2001-04-03
申请号：BR0002917
申请日：2000-07-17
Applicant: LUCENT TECHNOLOGIES INC
Inventor： KRISHNAMOORTHY RAJEEV , VISWANATHAN HARISH , LI XIAODONG , NARAYANASWAMY SHANKAR , RUPP MARKUS
Abstract: In a wireless communication system, the constellation mapping scheme employed may be changed on a per-time-slot basis, i.e., from time slot to time slot, so that the constellation used to encode the symbols of each time slot may be different for each time slot within a single frame and may be different for a particular time slot in different consecutive frames. In other words, several constellation mapping schemes are available, with each providing the ability to transmit a different number of bits per symbol, and the particular constellation mapping scheme employed for any time slot need be selected for that time slot only. The ability to use any particular constellation mapping scheme is dependent on the current channel quality. The particular constellation mapping used for the user data of the time slot may be indicated in the preamble of the time slot. To this end, each time slot may have its own preamble that is mapped with a constellation mapping scheme which is a) known Ù priori, b) may be the same for all time slots, and c) may be different from the constellation mapping scheme used to encode user data in the time slot. A receiver can determine the constellation mapping used for each time slot from solely from the preamble of the time slot.
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公开(公告)号：DE60138506D1
公开(公告)日：2009-06-10
申请号：DE60138506
申请日：2001-04-30
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LI XIAODONG , PAPADIAS CONSTANTINOS BASIL , VISWANATHAN HARISH
Abstract: Wireless communications for frequency-selective fading channels is realized by employing a system including orthogonal frequency division multiplexing (OFDM) in combination with an at least two antenna transmit diversity arrangement. Specifically, OFDM converts a multipath channel into a plurality of narrowband subchannels each having flat fading. Then, the signals on the same frequency subchannels of the at least two antennas are grouped together. Considering a first frequency subchannel, during a first OFDM time interval, a first signal and a second signal are transmitted on the first frequency subchannel from a first antenna (0) and from a second antenna (1), respectively. During a second OFDM time interval, a reverse sign (-) complex conjugate of the second signal and a complex conjugate of the first signal are transmitted from the first antenna and the second antenna, respectively. In a specific embodiment of the invention, reduced complexity in the implementation is realized by a reverse order complex conjugate and a reverse order, reverse sign (-) complex conjugate and judicious selection of the processed data signals in order to transmit the appropriate ones of the signals during the first and second OFDM intervals. Again, if the channel remains constant over the two OFDM intervals, diversity combination is realized for each frequency subchannel. In another embodiment of the invention, antenna-group hopping is employed in conjunction with pairing in time of the OFDM frequency subchannel signals to realize increased transmit diversity without rate loss.
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公开(公告)号：CA2341808A1
公开(公告)日：2001-11-09
申请号：CA2341808
申请日：2001-03-23
Applicant: LUCENT TECHNOLOGIES INC
Inventor： PAPADIAS CONSTANTINOS B , VISWANATHAN HARISH , LI XIAODONG
Abstract: Wireless communications for frequency-selective fading channels is realized by employing a system including orthogonal frequency division multiplexing (OFDM) in combination with an at least two antenna transmit diversity arrangement. Specifically, OFDM converts a multipath channel into a plurality of narrowband subchannels each having flat. fading. Then, the signals on the same frequency subchannels of the at least two antennas are grouped together. Considering a first frequency subchannel, during a first OFDM time interval, a first signal and a second signal are transmitted on the first frequency subchannel from a first antenna (0) and from a second antenna (1), respectively. During a second OFDM time interval, a reverse sign (-) complex conjugate of the secon d signal and a complex conjugate of the first signal are transmitted from the first antenna and the second antenna, respectively. In a specific embodiment of th e invention, reduced complexity in the implementation is realized by a reverse order complex conjugate and a reverse order, reverse sign (-) complex conjugate an d judicious selection of the processed data signals in order to transmit the appropriate ones of the signals during the first and second OFDM intervals. Again, if the channel remains constant over the two OFDM intervals, diversi ty combination is realized for each frequency subchannel. In another embodiment of the invention, antenna-group hopping is employed in conjunction with pairing in time of the OFDM frequency subchannel signals to realize increased transmit diversity without rate loss.
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公开(公告)号：CA2313817C
公开(公告)日：2005-02-15
申请号：CA2313817
申请日：2000-07-12
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LI XIAODONG , NARAYANASWAMY SHANKAR , RUPP MARKUS , KRISHNAMOORTHY RAJEEV , VISWANATHAN HARISH
Abstract: In a wireless communication system, the constellation mapping scheme employ ed may be changed on a per-time-slot basis, i.e., from time slot to time slot, so that the constellation used to encode the symbols of each time slot may be different for each time slot within a single frame and may be different for a particular time slot i n different consecutive frames. In other words, several constellation mapping schemes ar e available, with each providing the ability to transmit a different number of bits per symbol, and the particular constellation mapping scheme employed for any time slot need be selected for that time slot only. The ability to use any particular constellation mapping scheme is dependent on the current channel quality. The particular constellation mappi ng used for the user data of the time slot may be indicated in the preamble of the time slot. To this end, each time slot may have its own preamble that is mapped with a constellation mapping scheme which is a) known a priori, b) may be the same for all time slots, and c) may be different from the constellation mapping scheme used to encode user data in the time slot. A receiver can determine the constellation mapping used for each time slot from solely from the preamble of the time slot.
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公开(公告)号：DE60000395T2
公开(公告)日：2003-04-03
申请号：DE60000395
申请日：2000-07-17
Applicant: LUCENT TECHNOLOGIES INC
Inventor： KRISHNAMOORTHY RAJEEV , LI XIAODONG , NARAYANASWAMY SHANKAR , RUPP MARKUS , VISWANATHAN HARISH
Abstract: In a wireless communication system, the constellation mapping scheme employed may be changed on a per-time-slot basis, i.e., from time slot to time slot, so that the constellation used to encode the symbols of each time slot may be different for each time slot within a single frame and may be different for a particular time slot in different consecutive frames. In other words, several constellation mapping schemes are available, with each providing the ability to transmit a different number of bits per symbol, and the particular constellation mapping scheme employed for any time slot need be selected for that time slot only. The ability to use any particular constellation mapping scheme is dependent on the current channel quality. The particular constellation mapping used for the user data of the time slot may be indicated in the preamble of the time slot. To this end, each time slot may have its own preamble that is mapped with a constellation mapping scheme which is a) known Ù priori, b) may be the same for all time slots, and c) may be different from the constellation mapping scheme used to encode user data in the time slot. A receiver can determine the constellation mapping used for each time slot from solely from the preamble of the time slot.
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