Ericsson Ab

Marconi Communications Gmbh

Heike Hofmann

Thomas Alberty

Volker Hespelt

Khaled Fazel

Franz J Hagmanns

A method for monitoring a redundant (passive) transmitter, being, for example, part of a base station of a point-to-multipoint radio communications system transmits, during normal operation, a spread-spectrum signal over the redundant transmitter, the spread-spectrum signal being of low spectral power in comparison with data signals being transmitted by the active transmitter of the base station. One or more receivers are associated, for example, with terminal stations in communication with the base station and detect the presence of the spread-spectrum signal. If the spread-spectrum signal is not found to be present, the receivers provide an indication of this, and from this indication, a decision is made as to the integrity of the redundant transmitter.

Method and apparatus for monitoring a redundant (standby) transmitter in a radio communications system

A predistorter is connected upstream of a high-frequency amplifier to be linearized. A predistortion factor is adaptively modified in the predistorter in such a way as to compensate non-linearities of the amplifier as well as possible. The quotient of the output signal of the high-frequency amplifier and the input signal of the predistorter is produced first. An average amplification is then determined based on the signal quotient. A correction term is produced for the predistortion factor, this correction term being dependent on the extent of the deviation of the average amplification from a set value. The predistortion factor is adaptively modified in such a way as to minimize the correction term.

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Backnang, Germany

Heike Hofmann