St-Ericsson Sa

Rainer Dietsch

Harald Bauer

Peter Bode

Markus Helfenstein

Alexander Lampe

A controller is configured to determine a word in a set of words corresponding to a received coding value, the set of words including at least one data word, at least one modulator command word and at least one gain command word. When the received coding value corresponds to a data word, the controller causes the data word to be modulated. When the received coding value corresponds to a modulator command word, the controller controls a modulator based on the modulator command word. When the received coding value corresponds to a gain command word, the controller controls a gain based on the gain command word.

Enhanced bit mapping for digital interface of a wireless communication equipment in multi-time slot and multi-mode operation

Modulator system () comprising modulators () for modulating input signals (A) according to different modulation schemes (8PSK, GMSK) cause discontinuities in the output signals (F) when switching between the schemes. By providing the modulator systems () with compensators (-) for compensating amplitudes/phases of the output signals (F) of the modulator system () for discontinuities, these discontinuities resulting from modulation scheme changes are reduced to a large extent. This may be done before/after the pulse shapers (). The compensators (-) comprise multipliers for multiplying pulse shaped modulated signals with complex valued waveforms (E), or for multiplying modulated signals with waveforms (S, T), or for multiplying complex valued signals (B, C, D) with complex valued phase offsets (X, Y, Z), which complex valued signals (B, C, D) are to be multiplied with mapped input signals. As a result, the output signals (F) and/or power amplifiers () situated after the modulator system () no longer need to be ramped down.

Avoidance of discontinuities when switching between modulation schemes

The present invention relates to a digital I/Q modulator which efficiently supports multi-time-slot operation of wireless TDMA transmitters employing linear power amplifiers. According to the present invention, dips are introduced in the envelope of the I/Q signal in the guard interval between adjacent time-slots or bursts. The dips avoid interference on adjacent radio frequency channels when the gain of the TX chain in switched abruptly in order to change the power level of the TX signal or when the modulation scheme is changed. Also, a method is provided for generating the dips, which is particularly attractive if the modulation scheme in adjacent time-slots changes from GMSK to 8PSK or vice versa.

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Heroldsberg, Germany

Rainer Dietsch