Abstract: Methods and apparatus are described for improving receiver performance in a multicarrier communication network in which an encoded symbol is transmitted over a transmission channel in the communications system. A model of the transmission channel is estimated, said model characterising an effect of intercarrier interference on at least one carrier in the multicarrier system. The received symbol is decoded using the estimated model to remove a predicted effect of intercarrier interference. A pre-processor is also described for operation in conjunction with a communications receiver in the network. The pre-processor includes a channel estimator operable to estimate at least one feature of the communication channel based on a received signal. The pre-processor modifies the received signal dependent on the at least one estimated feature and provides the modified signal to the communications receiver.

Abstract: Methods and apparatus are described for improving receiver performance in a multicarrier communication network in which an encoded symbol is transmitted over a transmission channel in the communications system. A model of the transmission channel is estimated, said model characterising an effect of intercarrier interference on at least one carrier in the multicarrier system. The received symbol is decoded using the estimated model to remove a predicted effect of intercarrier interference. A pre-processor is also described for operation in conjunction with a communications receiver in the network. The pre-processor includes a channel estimator operable to estimate at least one feature of the communication channel based on a received signal. The pre-processor modifies the received signal dependent on the at least one estimated feature and provides the modified signal to the communications receiver.

Abstract: Methods and apparatus are described for improving receiver performance in a multicarrier communication network in which an encoded symbol (250) is transmitted over a transmission channel (20) in the communications system. A model of the transmission channel (20) is estimated (718, 760), said model characterizing an effect of intercarrier interference on at least one carrier in the multicarrier system. The received symbol (250) is decoded (720, 762) using the estimated model to remove a predicted effect of intercarrier interference. A pre-processor (40) is also described for operation in conjunction with a communications receiver (30) in the network. The pre-processor (40) includes a channel estimator (42) operable to estimate at least one feature of the communication channel based on a received signal. The pre-processor (40) modifies the received signal dependent on the at least one estimated feature and provides the modified signal to the communications receiver (30).

Abstract: A mass spectrometry system based on the general principle of accelerator mass spectrometry (AMS) is disclosed. An ion source (10) generates a beam (B) of ions having a negative charge state. A first mass analyzer (20) transmits only ions having a predetermined mass. The ions are passed through a stripper target (80) comprising helium and/or hydrogen as a stripping gas to change the charge state of said ions from negative to positive charge and to dissociate molecular ions by collisions. A second mass analyzer (110, 130) transmits ions in charge state 1+ having the predetermined mass, which are detected by a detector (140). By using helium and/or hydrogen gas and detecting ions in charge state 1+, it becomes possible to use kinetic energies below 200 keV without excessive transmission losses due to angular straggling. At sufficiently low energies, no additional acceleration is required after ions have been extracted from the ion source.

Abstract: A mass spectrometry system based on the general principle of accelerator mass spectrometry (AMS) is disclosed. An ion source (10) generates a beam (B) of ions having a negative charge state. A first mass analyzer (20) transmits only ions having a predetermined mass. The ions are passed through a stripper target (80) comprising helium and/or hydrogen as a stripping gas to change the charge state of said ions from negative to positive charge and to dissociate molecular ions by collisions. A second mass analyzer (110, 130) transmits ions in charge state 1+ having the predetermined mass, which are detected by a detector (140). By using helium and/or hydrogen gas and detecting ions in charge state 1+, it becomes possible to use kinetic energies below 200 keV without excessive transmission losses due to angular straggling. At sufficiently low energies, no additional acceleration is required after ions have been extracted from the ion source.

Abstract: Methods and apparatus are described for improving receiver performance in a multicarrier communication network in which an encoded symbol (250) is transmitted over a transmission channel (20) in the communications system. A model of the transmission channel (20) is estimated (718, 760), said model characterising an effect of intercarrier interference on at least one carrier in the multicarrier system. The received symbol (250) is decoded (720, 762) using the estimated model to remove a predicted effect of intercarrier interference. A pre-processor (40) is also described for operation in conjunction with a communications receiver (30) in the network. The pre-processor (40) includes a channel estimator (42) operable to estimate at least one feature of the communication channel based on a received signal. The pre-processor (40) modifies the received signal dependent on the at least one estimated feature and provides the modified signal to the communications receiver (30).