High capacity orthogonal frequency division multiple accessing systems and methods

An OFDM receiver comprised of:

• a receive antenna for receiving the bandpass OFDM signal;
• an RF to baseband conversion subsystem for providing the received serial OFDM signal;
• a multicarrier demodulator for providing the received symbol vector from the received serial OFDM signal;
• a vector splitter for providing a respective first and a second received symbol vector comprised of the elements of the received symbol vector with odd and even indices respectively;
• a first and a second inverse transform units for providing a respective first and second inverse transformed symbol vector form the respective first and second received symbol vector;
• a symbol detection subsystem for providing a mutual interference mitigated estimates of a first and second multiplicity MI of information modulation symbols;
• and
• a bank of baseband demodulators for providing estimates of users' data.

A method for OFDM transmission and reception of user input data, the transmission method comprising:

• implementing, by the computer device, a respective first and a second baseband processing subsystems for receiving and modulating user input data from a respective first and a second groups of users of a multiplicity Mu providing the, in general complex valued, a respective first and a second transformed symbols vectors of a dimension M greater than or equal to Mu;
• implementing, by the computer device, a subsystem for the generation of an OFDM signal vector, the subsystem comprised of:
• a multi carrier modulator for modulating the components of the first and second transformed symbols vectors by a respective first and a second groups of subcarriers with a frequency spacing of 2Δf for generating a first and a second OFDM signal vectors of dimension M;
• a frequency shifter for shifting the center frequency of the components of the second OFDM signal vector by a frequency shift of an integer multiple of Δf for providing a frequency shifted second OFDM signal vectors wherein the integer multiple is selected from a group comprised of integer 0 and odd integers less than 2M;
• and
• an adder for summing the first and the frequency shifted second OFDM signal vectors for providing an OFDM signal vector;
• implementing, by the computer device, a cascade of a parallel to serial converter, a guard interval insertion block, and a baseband filtering unit for providing a baseband OFDM signal;
• implementation of a carrier modulator unit and a radio frequency (RF) power amplifier for the generation of a bandpass OFDM signal;
• and
• transmission by a transmit antenna.