Abstract:
A telecommunications system comprises a transmitter within the central terminal for sending a data message destined for a particular subscriber terminal over communication channels as a number of data blocks. A frame generator is provided within the central terminal for generating a number of frames to represent each data block, each frame having a header portion and data portion. The header portion is arranged to be transmitted in a fixed format chosen to facilitate reception of the header portion by each subscriber terminal, and is arranged to include a number of control fields for providing information about the data portion. The data portion is arranged to be transmitted in a variable format.
Abstract:
A receiver for detecting and recovering data from received data bearing radio signal samples comprises first and second detecting processors. Each of the detecting processors comprises a data store operable to store a predetermined number of the signal samples, an equalizer operable to combine the signal samples with a plurality of equalizer coefficients, to produce refined signal samples representative of the received signal samples but with the effect of inter-symbol interference caused by multi-path propagation experienced by the received radio signals at least partially reduced, a combiner operable to receive the refined signal samples from the equalizer and to receive second refined signal samples, from the other detecting processor, derived from a further received version of the received signals, and to combine the first and second refined signal samples, and a data processor operable to receive the stored signal samples from the data store, and to receive second stored signal samples and to adapt the equalizer coefficients for the first detecting processor and the equalizer coefficients for the second detecting processor, to the effect of increasing the probability of correctly recovering the data from the received radio signal samples. By communicating the stored signal samples from the sample store of each of the detecting processors to one of the data processors acting as a master detecting processor, the equalizer coefficients for the equalizer for each detecting processor can be calculated together to the effect of increasing the probability of correctly recovering the data from the combined signals. In preferred embodiments the equalizer is a linear equalizer. The receiver finds application, in particular but not exclusively, in recovering data from spread spectrum radio signals, as used for example in CDMA systems.
Abstract:
The present invention relates to a telecommunications system and method for connecting to a network and for routing data of a plurality of different data types between the network and subscriber terminals of the telecommunications system. The subscriber terminals are connectable to a central terminal of the telecommunications system via a transmission medium, the telecommunications system providing a number of communication channels arranged to utilize the transmission medium for transmission of data between the central terminal and the subscriber terminals. The telecommunications system comprises a transmitter having first transmission processing logic for employing a first transport mechanism to transmit data and second transmission processing logic for employing a second transport mechanism to transmit data. A switching element is then provided for routing data for transmission to either the first or second transmission processing logic dependent on first predetermined criteria, the first predetermined criteria comprising at least the data type of the data for transmission. In addition, a resource allocation logic is provided for determining based on second predetermined criteria which of the communication channels to allocate for use by the first transmission processing logic, and which of the communication channels to allocate for use by the second transmission processing logic. This approach provides a very flexible transmission mechanism for improving the efficiency of transmission of data through the telecommunications system.