Telecommunication system and a main station for use in such a system
First Claim
1. A telecommunication system comprising:
- a main station and a plurality of substations, in which system communication between the main station and the substations occurs by transmission of data samples via a transmission channel in accordance with a multiple access protocol of respective time slots in successive data frames, which channel is common to the substations, wherein for coarse ranging the substations include ranging transmission means for transmitting in a data frame a ranging sequence of samples of low magnitude with respect to the magnitude of data samples to be transmitted in the time slots of said data frame, and the main station includes correlation means for recovering ranging information by correlating a received ranging sequence (rseq) with a reference sequence which is identical to a transmitted sequence, the main station comprising means for providing the reference sequence; and
, for coarse ranging, the correlation means principally correlates those samples of a received ranging sequence which fall within a time window reserved for ranging in said data frame.
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Abstract
Telecommunication systems such as PON-FITL-Systems are known having a TDMA frame structure and comprising a main station and a number of substations. The known systems can comprise apparatus for coarse ranging and for fine ranging. A Pseudo Noise Sequence based coarse ranging technique employs coarse ranging at a fixed position within the upstream multiframe reserved for ranging, preferably for fine ranging. By applying a low power Pseudo Noise Sequence for coarse ranging and sampling the range in the main station only within a fine ranging window the position of which is known to the main station, a more accurate coarse ranging is achieved. Within the fine ranging window normally no data are present, and thus the signal-to-interference ratio is an order of magnitude better than in the other part of the frame.
139 Citations
20 Claims
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1. A telecommunication system comprising:
- a main station and a plurality of substations, in which system communication between the main station and the substations occurs by transmission of data samples via a transmission channel in accordance with a multiple access protocol of respective time slots in successive data frames, which channel is common to the substations, wherein for coarse ranging the substations include ranging transmission means for transmitting in a data frame a ranging sequence of samples of low magnitude with respect to the magnitude of data samples to be transmitted in the time slots of said data frame, and the main station includes correlation means for recovering ranging information by correlating a received ranging sequence (rseq) with a reference sequence which is identical to a transmitted sequence, the main station comprising means for providing the reference sequence; and
, for coarse ranging, the correlation means principally correlates those samples of a received ranging sequence which fall within a time window reserved for ranging in said data frame. - View Dependent Claims (2, 3, 4, 5, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
- a main station and a plurality of substations, in which system communication between the main station and the substations occurs by transmission of data samples via a transmission channel in accordance with a multiple access protocol of respective time slots in successive data frames, which channel is common to the substations, wherein for coarse ranging the substations include ranging transmission means for transmitting in a data frame a ranging sequence of samples of low magnitude with respect to the magnitude of data samples to be transmitted in the time slots of said data frame, and the main station includes correlation means for recovering ranging information by correlating a received ranging sequence (rseq) with a reference sequence which is identical to a transmitted sequence, the main station comprising means for providing the reference sequence; and
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6. A telecommunication system comprising:
- a main station and a plurality of substations, in which system communication between the main station and the substations occurs by transmission of data samples via a transmission channel in accordance with a multiple access protocol of respective time slots in successive data frames, which channel is common to the substations, wherein for coarse ranging the substations include ranging transmission means for transmitting in a data frame a ranging sequence of samples of low magnitude with respect to the magnitude of data samples to be transmitted in the time slots of said data frame, correlation means for recovering ranging information by correlating a received ranging sequence relayed by the main station with a reference sequence which is identical to the transmitted sequence, and means for providing the reference sequence; and
, for coarse ranging, the correlation means principally correlate those samples of a received ranging sequence which fall within a time window reserved for ranging in said data frame.
- a main station and a plurality of substations, in which system communication between the main station and the substations occurs by transmission of data samples via a transmission channel in accordance with a multiple access protocol of respective time slots in successive data frames, which channel is common to the substations, wherein for coarse ranging the substations include ranging transmission means for transmitting in a data frame a ranging sequence of samples of low magnitude with respect to the magnitude of data samples to be transmitted in the time slots of said data frame, correlation means for recovering ranging information by correlating a received ranging sequence relayed by the main station with a reference sequence which is identical to the transmitted sequence, and means for providing the reference sequence; and
Specification