Abstract:
Embodiments of the present invention provide a signal processing method in a DSL system. The method includes: determining that there is no to-be-sent downstream signal on m subscriber lines in n subscriber lines; superimposing a signal X on the m subscriber lines, so that a signal output on the m subscriber lines after precoding processing is 0, where xm indicates a signal component loaded on the mth subscriber line in the m subscriber lines; performing precoding processing on a downstream signal on the n subscriber lines; and sending the downstream signal that has undergone the precoding processing on another line except the m subscriber lines in the n subscriber lines. The embodiments of the present invention further provide a network-side device and a DSL system.
Abstract:
Embodiments of the present invention disclose a signal transmission method. A first correspondence is acquired between both a PSD of transmitted signals of the first communications equipment and a PSD of transmitted signals of a second communications equipment and a signal-to-noise ratio of received signals of the first communications equipment. A second correspondence is acquired between the signal-to-noise ratio of received signals of the first communications equipment and the number of bits for bearing signals. An optimization algorithm is used to calculate a PSD of transmitted signals of the first communications equipment and a PSD of transmitted signals of the second communications equipment.
Abstract:
A method, apparatus, and system for time synchronization are disclosed. The method comprising: obtaining a master sending time stamp, a slave receiving time stamp, a slave sending time stamp, and a master receiving time stamp; and adjusting the time of the slave clock according to the offset calculated from the time stamps to synchronize with the clock time of the master clock. With the present invention, in passband transmission systems that transmit signals continuously in units of symbols, the time synchronization is implemented between the master clock and the slave clock.
Abstract:
Embodiments of the present invention provide a signal processing method in a DSL system. The method includes: determining that there is no to-be-sent downstream signal on m subscriber lines in n subscriber lines; superimposing a signal X on the m subscriber lines, so that a signal output on the m subscriber lines after precoding processing is 0, where xm indicates a signal component loaded on the mth subscriber line in the m subscriber lines; performing precoding processing on a downstream signal on the n subscriber lines; and sending the downstream signal that has undergone the precoding processing on another line except the m subscriber lines in the n subscriber lines. The embodiments of the present invention further provide a network-side device and a DSL system.
Abstract:
A method, apparatus, and system for time synchronization are disclosed. The method comprising: obtaining a master sending time stamp, a slave receiving time stamp, a slave sending time stamp, and a master receiving time stamp; and adjusting the time of the slave clock according to the offset calculated from the time stamps to synchronize with the clock time of the master clock. With the present invention, in passband transmission systems that transmit signals continuously in units of symbols, the time synchronization is implemented between the master clock and the slave clock.
Abstract:
The present invention provides a method, an apparatus, and a system for time synchronization of an xDSL. The method includes: transmitting, by a customer premises equipment, a first symbol to a central office equipment, and obtaining time Ts2 indicating the moment that the first symbol is transmitted; receiving, by the CPE, a second symbol transmitted by the CO, and obtaining time Ts1 indicating the moment that the second symbol is received; obtaining, by the CPE obtains time Tm2 indicating the moment that the first symbol is received by the CO and time Tm1 indicating the moment that the second symbol is transmitted by the CO; the CPE calculates an offset between a clock of the CPE and a clock of the CO according to Ts1, Ts2, Tm1 and Tm2; and the CPE adjusts the clock of the CPE according to the offset to achieve synchronization.
Abstract:
The present invention provides a method, an apparatus, and a system for time synchronization of an xDSL. The method includes: transmitting, by a customer premises equipment, a first symbol to a central office equipment, and obtaining time Ts2 indicating the moment that the first symbol is transmitted; receiving, by the CPE, a second symbol transmitted by the CO, and obtaining time Ts1 indicating the moment that the second symbol is received; obtaining, by the CPE obtains time Tm2 indicating the moment that the first symbol is received by the CO and time Tm1 indicating the moment that the second symbol is transmitted by the CO; the CPE calculates an offset between a clock of the CPE and a clock of the CO according to Ts1, Ts2, Tm1 and Tm2; and the CPE adjusts the clock of the CPE according to the offset to achieve synchronization.
Abstract:
Embodiments of the present invention disclose a signal transmission method. A first correspondence is acquired between both a PSD of transmitted signals of the first communications equipment and a PSD of transmitted signals of a second communications equipment and a signal-to-noise ratio of received signals of the first communications equipment. A second correspondence is acquired between the signal-to-noise ratio of received signals of the first communications equipment and the number of bits for bearing signals. An optimization algorithm is used to calculate a PSD of transmitted signals of the first communications equipment and a PSD of transmitted signals of the second communications equipment.
Abstract:
A clock synchronization method, apparatus, and system are provided according to the embodiments of the present invention. The method includes: receiving time information TM1 from a central office side, in which the time information TM1 is obtained by the central office side by reading a local clock of the central office side when transmission data at a first designated location starts to be transferred, and the local clock of the central office side is synchronous with a Global Positioning System (GPS) clock or a Building Integrated Timing Supply (BITS) clock; determining whether transmission data at a second designated location starts to be received, if so, reading a local clock of the Customer Premises Equipment side to obtain time information TS1; and synchronizing a clock frequency of the Customer Premises Equipment side to the central office side according to the time information TM1 and the time information TS1.