Signaling method in an OFDM multiple access system

A communication system for generating an OFDM signal having allocated frequency tones distributed over a predetermined bandwidth, the communication system comprising:

• a mapping module that receives data symbols from a symbol constellation and maps the symbols to prescribed time instants in a time domain symbol duration to generate a discrete signal of mapped symbols;
• an interpolation module that receives the discrete signal and generates a continuous signal by applying an interpolation function to the discrete signal;
• wherein the interpolation function operates on the discrete signal such that a frequency response of the continuous signal includes sinusoids having non-zero values at the allocated frequency tones, and zero values at frequency tones other than the allocated frequency tones;
• and
• a cyclic prefix circuit located after the interpolation module to prepend a cyclic prefix.

A communication system for generating an OFDM signal having allocated frequency tones distributed over a predetermined bandwidth, the communication system comprising:

• a mapping module that receives data symbols from a symbol constellation and maps the symbols to prescribed time instants in a time domain symbol duration to generate a discrete signal of mapped symbols;
• and
• an interpolation module that receives the discrete signal and generates a digital signal sample vector by applying an interpolation function to the discrete signal;
• wherein the interpolation function operates on the discrete signal such that a frequency response of the digital signal sample vector includes sinusoids having non-zero values at the allocated frequency tones, and zero values at frequency tones other than the allocated frequency tones;
• and
• a cyclic prefix module located after the interpolation module for prepending a cyclic prefix.

A communication system for generating an OFDM signal having allocated frequency tones distributed over a predetermined bandwidth, the communication system comprising:

• a mapping module that receives data symbols from a symbol constellation and maps the symbols to prescribed time instants in a time domain symbol duration to generate a discrete signal of mapped symbols;
• and
• an interpolation module that receives the discrete signal and generates a continuous signal by applying an interpolation function to the discrete signal;
• wherein the interpolation function operates on the discrete signal such that values of the continuous signal at the prescribed time instants are equal to the mapped symbols;
• and
• a cyclic prefix module located after the interpolation module to prepend a cyclic prefix.

A communication system comprising:

• a mapping circuit that receives data symbols and maps the symbols to prescribed time instants in a time domain symbol duration to generate a discrete signal of mapped symbols;
• and
• an interpolation circuit that receives the discrete signal and generates a continuous signal by applying an interpolation function that operates on the discrete signal such that a frequency response of the continuous signal includes sinusoids having non-zero values at a first set of tones, and zero values at a second set of tones;
• and
• a cyclic prefix module located after the interpolation circuit to prepend a cyclic prefix.

A communication system comprising:

• a mapping circuit that receives data symbols and maps the symbols to prescribed time instants in a time domain symbol duration to generate a discrete signal of mapped symbols;
• and
• an interpolation circuit that receives the discrete signal and generates a digital signal sample Vector by applying an interpolation function that operates on the discrete signal such that a frequency response of the digital signal sample vector includes sinusoids having non-zero values at a first set of tones, and zero values at a second set of tones;
• and
• a cyclic prefix circuit located after the interpolation module to prepend a cyclic prefix.

A method for reducing a peak-to-average ratio in an OFDM communication signal transmitted by a communication device, the method comprising:

• providing a time domain symbol duration having equally spaced time instants;
• allocating a predetermined number of frequency tones to the communication device;
• receiving as input data symbols to be transmitted by the OFDM communication signal;
• mapping the data symbols to the equally spaced time instants in the symbol duration to generate a discrete signal of mapped symbols;
• generating a continuous signal by applying an interpolation function to the discrete signal, the interpolation function operating on the discrete signal such that a frequency response of the continuous signal includes sinusoids having non-zero values at the allocated frequency tones, and zero values at frequency tones other than the allocated frequency tones;
• and
• sampling the continuous signal at discrete time instants distributed over the time domain symbol duration, to generate a digital signal sample vector;
• and
• prepending a cyclic prefix to the digital signal sample vector produced by sampling the continuous signal after generation of the continuous signal by applying the interpolation function.

A method for reducing a peak-to-average ratio in an OFDM communication signal having a set of tones distributed over a predetermined bandwidth, the method comprising:

• defining a symbol duration for the OFDM communication signal;
• defining time instants in the symbol duration;
• allocating frequency tones from the set of tones to a particular communication device;
• receiving as input data symbols from a symbol constellation, the data symbols being transmitted by the OFDM communication signal;
• mapping the data symbols to the time instants to generate a discrete signal in the time domain;
• generating a digital signal sample vector by applying interpolation functions to the discrete signal such that a frequency response of the digital signal sample vector includes sinusoids having non-zero values at allocated frequency tones, and zero values at frequency tones other than the allocated frequency tones;
• and
• prepending a cyclic prefix to the digital signal sample vector after the digital signal sample vector is generated by applying the interpolation function.

A communication device for use in a communications system that uses multiple tones distributed over a predetermined bandwidth to communicate data, the device comprising:

• a mapping circuit that receives data symbols and maps the symbols to prescribed time instants in a predetermined time interval to generate a discrete signal including mapped symbols, each mapped symbol corresponding to a discrete point in time, each discrete point in time to which a symbol is mapped not overlapping a discrete point in time to which another symbol is mapped, multiple symbols being mapped to said predetermined time interval, discrete points in time to which symbols are mapped having a predetermined spacing;
• an interpolation circuit that receives the discrete signal and generates a continuous signal by applying an interpolation function to the discrete signal, the interpolation function operating on the discrete signal such that a frequency response of the continuous signal includes sinusoids having non-zero values at a first set of tones, the first set of tones being a subset of said multiple tones, the non-zero value at each of said first set of tones being a function of a plurality of mapped symbols corresponding to different discrete points in time, the frequency response of the continuous signal also including zero values at a second set of tones, the second set of tones being different from said first set of tones and being another subset of said multiple tones;
• and
• a cyclic prefix circuit located after the interpolation circuit for prepending a cyclic prefix.