Method and apparatus for multi-carrier frequency division multiplexing transmission

1. A transmitter for data transmission by a frequency division multiplexing (FDM) method, comprising:

the transmitter being adapted and configured to:

detect vacant frequency ranges in a plurality of allocated frequency ranges of a transmission frequency band,

define a single center frequency for each of said detected vacant frequency ranges as a divisional multiplex carrier frequency, and

transmit information about said detected vacant frequency ranges and defined center frequencies to a receiver through an established communication channel,

said transmitter further comprising:

digital means for channel encoding an incoming stream of bits and for mapping the channel encoded bits to symbols, wherein the mapping is individual per carrier frequency;

digital mapping means for mapping said symbols to the defined carrier frequencies;

a plurality of parallel processing branches coupled to said digital mapping means, each branch comprising means for adding a cyclic prefix to a symbol, means for digital pulse shaping a symbol, wherein the pulse shaping is individual per carrier frequency, thus producing non-orthogonal carriers, and a complex multiplier for shifting a symbol to carrier frequencies;

a complex adder for adding symbols processed by said plurality of parallel branches thus producing a single digital transmit signal; and

means for digital-to-analogue converting, upconverting and amplifying the single transmit signal for transmission.

2. The transmitter arrangement of claim 1 , wherein each of the plurality of parallel processing paths comprises means for performing a tail biting technique to shorten the cyclic prefix of a symbol.

3. The transmitter of claim 1 , wherein said pulse shaping means is adapted and configured to minimize mutual interference between said frequency divisional multiplexing carriers.

4. A receiver for receiving a plurality of non-orthogonal frequency divisional multiplexed radio signals, comprising:

the receiver being adapted and configured to receive information from a transmitter through an established communication link about vacant frequency ranges in a plurality of allocated frequency ranges detected by the transmitter and a single center frequency for each of said detected vacant frequency ranges as a divisional multiplex carrier frequency defined by said transmitter, said receiver further comprising:

an analogue input stage for amplifying and down converting a received signal and for analogue-to-digital converting said received signal;

a plurality of parallel digital processing paths, each coupled to said analogue input stage and each adapted and configured for digitally down-converting the received signal to an individual carrier frequency and for outputting transmit symbols mapped to said individual carrier frequency;

a carrier de-mapping means coupled to each of the plurality of parallel processing paths for individually de-mapping symbols from carrier frequencies; and

a detector/decoder means coupled to said carrier de-mapping means for decoding bits from the symbols.

5. The receiver of claim 4 , wherein each of the parallel digital processing paths comprises:

a complex multiplier for mixing the received signal to an individual carrier frequency;

a pulse shaping means for removing inter channel interference; and

means for removing a cyclic prefix of symbol.

6. The receiver of claim 5 , wherein each of the parallel digital processing paths further comprises a Fast Fourier Transformation (FFT) processing block followed by an equalization processing block followed by an inverse Fast Fourier Transformation Block.