Patent ID: 7301891

Claim:
An SLM (Selected Mapping) apparatus for converting a signal block including a plurality of signals corresponding to a plurality of sub-carriers contained in a frequency domain for use in a transmitter of an OFDM (Orthogonal Frequency Division Multiplexing) communication system into a plurality of signal sequences contained in a time domain, and selecting a signal sequence having a lowest PAPR (Peak-to-Average Power Ratio) among the converted signal sequences, the SLM apparatus comprising: a single IFFT (Inverse Fast Fourier Transformer) for performing an Inverse Fast Fourier Transform process on the plurality of signals of the signal block and generating a conversion sequence symbol having a plurality of samples; a shift register for storing the plurality samples of the conversion sequence symbol generated from the IFFT, a plurality of multiplier groups each including a plurality of multipliers, and a plurality of adder groups each having an adder for adding up output values of the plurality of multipliers included in each of the plurality of multiplier groups; wherein the shift register includes a plurality of memories serially connected to each other for storing individual samples and acts as a cyclic shift register for connecting an output terminal of a last memory among the memories to an input terminal of a first memory among the memories, such that a first input sample among the individual samples is applied to the first memory when it is generated from the last memory; and wherein the plurality of multipliers are each connected to output terminals of the plurality of memories, receive a plurality of mask coefficient groups, each including mask coefficients for generating a plurality of signal sequences containing a signal sequence having the lowest PAPR, and multiply output values of the plurality of memories by another received mask coefficient group among the received plurality of mask coefficient groups, whenever the individual samples of the shift register are circulated.