Method and base station for orthogonal frequency division multiplexing (ofdm) signal processing

A method of forming a baseband signal from an OFDM signal, including the steps of:

• down-converting partially overlapping radio frequency bands of the OFDM signal to corresponding prefixed OFDM symbols;
• removing a cyclic prefix from each down-converted prefixed OFDM symbol to form un-prefixed OFDM symbols;
• transforming the unprefixed OFDM symbols into baseband sub-blocks mapped to adjacent OFDM sub-carrier blocks;
• de-mapping the baseband sub-blocks from the adjacent OFDM sub-carrier blocks;
• performing phase compensations after down-conversion so that the de-mapped baseband sub-blocks will correspond to unprefixed OFDM symbols that start at the same phase;
• and
• combining the phase compensated de-mapped baseband sub-blocks into a baseband signal.

A base station arrangement for forming an OFDM signal from a baseband signal, said base station comprising:

• a partitioning unit configured to partition a block of baseband signal samples into sub-blocks;
• a sub-carrier mapper configured to map the sub-blocks onto adjacent sub-carrier blocks of an OFDM multi-carrier;
• a plurality of transforming units configured to transform each mapped sub-block into a corresponding unprefixed OFDM symbol;
• a plurality of cyclic prefix adders configured to add a cyclic prefix to each mapped sub-block to form prefixed OFDM symbols;
• a plurality of phase compensators configured to perform phase compensations forcing the unprefixed OFDM symbol part of all prefixed OFDM symbols to start at the same phase after subsequent up-conversion to radio frequency;
• a plurality of up-converters configured to up-convert the phase compensated prefixed OFDM symbols to respective radio frequency bands having center frequencies and bandwidths that preserve the OFDM multi-carrier structure;
• and
• a combiner configured to combine the up-converted phase compensated prefixed OFDM symbols into an OFDM signal.

A base station arrangement for forming a baseband signal from an OFDM signal, said base station comprising:

• a plurality of down-converters configured to down-convert partially overlapping radio frequency bands of the OFDM signal to corresponding prefixed OFDM symbols;
• a plurality of cyclic prefix removers configured to remove a cyclic prefix from each down-converted prefixed OFDM symbol to form unprefixed OFDM symbols;
• a plurality of transforming units configured to transform the un-prefixed OFDM symbols into baseband sub-blocks mapped to adjacent OFDM sub-carrier blocks;
• a sub-carrier de-mapper configured to de-map the baseband sub-blocks from the adjacent OFDM sub-carrier blocks;
• a plurality of phase compensators configured to perform phase compensations after down-conversion so that the de-mapped baseband sub-blocks will correspond to un-prefixed OFDM symbols that start at the same phase;
• and
• a combiner configured to combine the phase compensated de-mapped baseband sub-blocks into a baseband signal.