Abstract:
A data stream provided to a DMT transmitter (114) is altered to produce an ordered data stream. The ordered data stream is produced by storing the data stream using a first addressing scheme, and then reading the data using a second addressing scheme. The ordered data stream is then converted in to a DMT symbol which is transmitted to a DMT receiver (112). The DMT receiver (112), using the first and second addressing schemes, recovers the ordered data stream and then the original data stream.
Abstract:
A communication system (100) includes a primary site (102) coupled to a plurality of secondary sites (104-108) using DMT technology. The primary site (102) includes a controller, a data multiplexing switch, a Discrete Multi-Tone transmitter, and a Discrete Multi-Tone receiver. Each of the secondary sites (104-108) includes a site controller, a subscriber interface, and a secondary Discrete Multi-Tone receiver.
Abstract:
In a communication system that utilizes DMT technology to couple a primary site (102) to a plurality of secondary sites (104-108), the primary site (102) and each of the secondary sites (104-108) includes a DMT transmitter. Such a DMT transmitter includes a discrete multi-tone encoder that receives an ordered data stream and produces an encoded data stream based on bit loading information, and a data formatter operably coupled to the discrete multi-tone encoder, wherein the data formatter receives transmit data entries and produces the ordered data stream based on carrier channel allocation information.
Abstract:
In a communication system that utilizes DMT technology to couple a primary site (102) to a plurality of secondary sites (104-108), carrier channel allocations may be performed as follows. When a call request is received, the primary site (102) determines the number of required bits based on the bandwidth requirements of the call. Next, the primary site (102) determines whether the maximum bit loading of a given carrier channel exceeds the number of required bits. If yes, the primary site allocates a carrier channel having a bit loading that most closely matches the number of required bits. If no, the primary site allocates the carrier channel having the maximum bit loading to the call, then calculates a remaining number of required bits. From here, the primary site repeats the above process until a sufficient number of carrier channels have been allocated to the call.
Abstract:
In the present invention, carriers associated with a discrete multi-tone (DMT) communications system (10) are sorted according to bit allocation capacity. The number of bits needed to attain a specified bit rate are then allocated beginning with the carrier having the greatest bit allocation capacity and proceeding toward the carrier having the least bit allocation capacity until all bits to are allocated. Once allocated, the power to any unused bins is reduced. Different subsets of the carriers between line cards can be specified in order to reduce crosstalk between adjacent lines.
Abstract:
A symbol generator (804) generates a time-domain discrete multi-tone symbol (810). A magnitude comparator (812) compares the magnitude of the time-domain discrete multi-tone symbol (810) with a magnitude threshold. When the magnitude of the time-domain discrete multi-tone symbol (810) compares unfavorably to the magnitude threshold, a magnitude adjusting symbol (816) is added to the time-domain discrete multi-tone symbol (810) such that the magnitude of the time-domain discrete multi-tone symbol (810) is reduced, thereby reducing the peak-to-average requirements (PAR).
Abstract:
A voice gateway (18) in a telecommunications network (1) includes a plurality of telephony port modules (102). Each telephony port module (102) receives telephony voice signals from a public switched telephony network (13). Each telephony port module (102) includes one or more digital signal processors (110) that perform one or more processing functions on the telephony voice signals. A particular telephony port module (102) may receive a telephony voice signal and use its associated digital signal processor (110) to process the received telephony voice signal or transfer the received telephony voice signal for processing to any digital signal processor (110) on any telephony port module (102). Telephony signals may also be transferred for processing to digital signal processors (110) on another voice gateway (18) in a voice gateway system.
Abstract:
A backplane (11) of a telecommunications chassis includes a pair of controller slots that can receive respective controller modules. The backplane (11) also has a plurality of module slots that can receive respective telephony modules. Each of the pair of controller slots is connected by a plurality of buses to each of the plurality of module slots. The backplane (11) provides the ability to place any module type into any of the plurality of module slots.
Abstract:
An echo canceler (34) includes a summing device (104) that subtracts a correction signal from a received signal, the difference of which represents the far-end signal with an error component. Instead of adapting its coefficients using the output of the summing device (104), the echo canceler (34) uses the difference between the input and output of a decision device (108) as an estimate of the error component alone. The estimate of the error component is then used to adapt the coefficients according to the adaptive least mean squares (LMS) algorithm. In one embodiment, the decision device (108) forms discrete multi-tone symbols based on the equalized output of the summing device. In this embodiment, the echo canceler (34) performs an inverse of the equalization step efficiently by replacing a division operation with a multiply operation and a corresponding power-of-two shift operation.
Abstract:
In a communication system that utilizes DMT technology to couple a primary site (102) to a plurality of secondary sites (104-108), the primary site (102) and each of the secondary sites (104-108) includes a DMT receiver. Such a DMT receiver includes a discrete multi-tone decoder that receives a time domain discrete multi-tone symbol and produces an ordered data stream based on bit loading information and a data de-formatter, operably coupled to the discrete multi-tone decoder, wherein the data de-formatter receives the ordered data stream and produces a recovered data stream based on carrier channel allocation information.