Optimizing link quality by space and time interleaving

A radio transmitter comprising:

• a channel coder for channel encoding data to be sent;
• an interleaver, connected to the channel coder, for interleaving the channel coded data;
• a space diversity block connected to the interleaver;
• at least two transmit blocks connected to the space diversity block;
• a transmit block comprising a modulation block for transmitting modulated, interleaved and channel coded data in a radio channel, and an antenna connected to the modulation block;
• coherence time means for determining a radio channel coherence time;
• transfer delay means for detecting a data transfer delay requirement;
• interleaving selection means for selecting an interleaving depth using the radio channel coherence time and the data transfer delay as decisive parameters, the interleaving selection means obtaining an input from the coherence time means and the transfer delay means, and interleaving selection means giving interleaving depth as an input to the interleaver;
• quality means for detecting a radio channel quality requirement according to the user and system information;
• and
• antenna diversity selection means for selecting at least one transmit diversity antenna besides the main antenna when the radio channel quality requirement is not fulfilled, so that the radio channel quality requirement will be fulfilled, the antenna diversity selection means obtaining the radio channel quality requirement as an input from the quality means, and the antenna diversity selection means giving the selected transmit blocks as an input to the space diversity block.