Method for overusing frequencies to permit simultaneous transmission of signals from two or more users on the same frequency and time slot

A method for increasing the number of users capable of communicating over a wireless network, comprising:

• transmitting information in a digital format from multiple separate wireless transmitters on the same frequency;
• and,
• separating the transmitted signals which arrive corrupted a receiver as a corrupted received signal so as to remove the interference of one signal from that of another using a Viterbi decoder to perform an exhaustive search and a joint parameter estimation, whereby multiple simultaneously transmitted signals may be recovered without requiring new waveforms or new frequencies slots or time slots, the separating step including the step of separating the received signals in terms of power so as to group the signals in terms of decreasing power by iteratively processing and stripping off the signals in the highest power group, thus to limit the total amount of processing required by the exhaustive search.

A method for increasing the number of users capable of communicating over a wireless network, comprising:

• transmitting information in a digital format from multiple separate wireless transmitters on the same frequency;
• and,
• separating the transmitted signals which arrive corrupted a receiver as a corrupted received signal so as to remove the interference of one signal from that of another using a Viterbi decoder to perform an exhaustive search and a joint parameter estimation, the separating step including the step of intersymbol interference tail chopping, thus to limit the number of states in the Viterbi decoder and thus the processing time by at least an order of magnitude, whereby multiple simultaneously transmitted signals may be recovered without requiring new waveforms or new frequencies slots or time slots.

A method for increasing the number of users capable of communicating over a wireless network, comprising:

• transmitting information in a digital format from multiple separate wireless transmitters on the same frequency;
• and,
• separating the transmitted signals which arrive corrupted a receiver as a corrupted received signal so as to remove the interference of one signal from that of another using a Viterbi decoder to perform an exhaustive search and a joint parameter estimation, the total number of transmitters being K, the grouping of signals by power reducing K into subgroups containing more than k users in each, where k is not so large as to preclude realtime processing, whereby multiple simultaneously transmitted signals may be recovered without requiring new waveforms or new frequencies slots or time slots.

A method for increasing the number of users capable of communicating over a wireless network, comprising:

• transmitting information in a digital format from multiple separate wireless transmitters on the same frequency;
• and,
• separating the transmitted signals at which arrive corrupted a receiver as a corrupted received signal so as to remove the interference of one signal from that of another using a Viterbi decoder to perform an exhaustive search and a joint parameter estimation, n being the length of the intersymbol interference and wherein n is reduced with tail chopping, thus to reduce the number of states per stage in the processing of the received signals from many hundreds of gigaflops to megaflops which can be accommodated by the computational capacity of a wireless handset, whereby multiple simultaneously transmitted signals may be recovered without requiring new waveforms or new frequencies slots or time slots.

A method for reducing the computational complexity of separating two digital signals that exist simultaneously on the same communication channel, comprising the step of:

• using parameter estimation and a Viterbi decoder to perform an exhaustive search algorithm to separate the bit streams corresponding to all the signals in the channel, the signals being separated into groups by received power, with the signals in the highest power group being processed first, thereby to limit computational complexity by doing an exhaustive search only on one group of signals at a time.