Multiple-access hybrid OFDM-CDMA system

In a multiple-access OFDM-CDMA system, a method for recovering data transmitted over a wireless communication channel, comprising:

• processing a received signal to provide data samples;
• decovering the data samples with a cover code to provide decovered samples;
• transforming the decovered samples in the frequency domain in accordance with a Fourier transform to provide transformed samples;
• despreading the transformed samples with one or more sets of despreading coefficients to provide despread samples, wherein each set of despreading coefficients is associated with a respective despreading code that corresponds to a spreading code used to spread data prior to transmission and selected from a set of available spreading codes;
• combining the despread samples for each time interval to provide a demodulated symbol representative of a transmitted OFDM symbol;
• and
• decoding demodulated symbols to provide decoded data.

A receiver unit in a multiple-access OFDM-CDMA system, comprising:

• a receiver operative to process a received signal to provide data samples;
• a transformer operative to transform the data samples in the frequency domain in accordance with a particular transformation to provide transformed samples;
• a despreader operative to despread the transformed samples with one or more sets of despreading coefficients to provide despread samples, wherein each set of despreading coefficients is associated with a respective despreading code that corresponds to a spreading code used to spread data prior to transmission and selected from a set of available spreading codes;
• a first summer operative to combine the despread samples for each time interval to provide a demodulated symbol representative of a transmitted OFDM symbol;
• and
• a RX data processor operative to decode demodulated symbols to provide decoded data.

A base station in a multiple-access OFDM-CDMA system, the base station comprising:

• an antenna to receive a signal;
• and
• a receiver unit to which the antenna provides the received signal, wherein the receiver unit comprises:
• a receiver operative to process the received signal to provide data samples;
• a transformer operative to transform the data samples in the frequency domain in accordance with a particular transformation to provide transformed samples;
• a despreader operative to despread the transformed samples with one or more sets of despreading coefficients to provide despread samples, wherein each set of dispreading coefficients is associated with a respective despreading code that corresponds to a spreading code used to spread data prior to transmission and selected from a set of available spreading codes;
• a first summer operative to combine the despread samples for each time interval to provide a demodulated symbol representative of a transmitted OFDM symbol;
• and
• a RX data processor operative to decode demodulated symbols to provide decoded data.

A terminal in a multiple-access OFDM-CDMA system, the terminal comprising:

• an antenna to receive a signal;
• and
• a receiver unit to which the antenna provides the received signal, wherein the receiver unit comprises:
• a receiver operative to process the received signal to provide data samples;
• a transformer operative to transform the data samples in the frequency domain in accordance with a particular transformation to provide transformed samples;
• a despreader operative to despread the transformed samples with one or more sets of despreading coefficients to provide despread samples, wherein each set of despreading coefficients is associated with a respective despreading code that corresponds to a spreading code used to spread data prior to transmission and selected from a set of available spreading codes;
• a first summer operative to combine the despread samples for each time interval
• to provide a demodulated symbol representative of a transmitted OFDM symbol;
• and
• a RX data processor operative to decode demodulated symbols to provide decoded data.

A receiver apparatus in a multiple-access OFDM-CDMA system, comprising:

• means for processing a received signal to provide data samples;
• means for transforming the data samples in the frequency domain in accordance with a particular transformation to provide transformed samples;
• means for despreading the transformed samples with one or more sets of despreading coefficients to provide despread samples, wherein each set of despreading coefficients is associated with a respective despreading code that corresponds to a spreading code used to spread data prior to transmission and selected from a set of available spreading codes;
• means for combining the despread samples for each time interval to provide a demodulated symbol representative of a transmitted OFDM symbol;
• and
• means for decoding demodulated symbols to provide decoded data.

A memory unit storing software codes, the software codes executable by a processor for:

• processing a received signal to provide data samples;
• transforming the data samples in the frequency domain in accordance with a particular transformation to provide transformed samples;
• despreading the transformed samples with one or more sets of despreading coefficients to provide despread samples, wherein each set of despreading coefficients is associated with a respective despreading code that corresponds to a spreading code used to spread data prior to transmission and selected from a set of available spreading codes;
• combining the despread samples for each time interval to provide a demodulated symbol representative of a transmitted OFDM symbol;
• and
• decoding demodulated symbols to provide decoded data.