Transmitter and receivers using resource sharing and coding for increased capacity

A receiver capable of receiving digital message burst signals transmitted by a remote transmitter in separate time slots of a time division multiple access (TDMA) frame sequence and destined for the receiver, where the transmitter uses (a) a first pair combination of a predetermined redundancy code of a plurality of different redundancy codes and a predetermined signal constellation of a plurality of different signal constellation for encoding each message burst signal for transmission in one time slot of the TDMA frame sequence when the carrier-to-noise ratio (CNR) is equal to or above a predetermined CNR in transmissions between the transmitter and receiver corresponding to a predetermined clear air condition, where each different signal constellation includes a set of points which is different and not a scalar replica of the set of points for each of the other signal constellations, and (b) a second pair combination of a predetermined redundancy code and a predetermined signal constellation for encoding each message burst signal for transmission in more than one time slot of the TDMA frame sequence when the transmission between the transmitter and receiver is below said predetermined CNR, the first pair combination being a fixed pair of a predetermined redundancy code and a predetermined signal constellation and the second pair combination comprising a selectively different pair of a predetermined redundancy code and a predetermined signal constellation than used for said first pair combination for achieving a high transmission capacity while maintaining low fade condition outage;

• the receiver comprising:
• filtering means (21) for generating an output signal comprising only signals received within a predetermined frequency band;
• demodulating means including a signal constellation demodulating means capable of translating a signal constellation comprising a predetermined set of points, received in each of the message burst signals destined for the receiver into an output signal indicative of a vector value of the output signal from the filtering means;
• and
• sequence estimating means including a decoding means capable of decoding the output signal of the demodulating means wherein each originally encoded message burst signal was encoded using a predetermined one of a plurality of redundancy codes to derive each remotely transmitted message burst signal in its original form.

In a time division multiple access (TDMA) communication system comprising a plurality of remote, spaced apart, stations which communicate with one another using digital message burst signals transmitted in assigned time slots of a frame sequence, a method of providing maximum data transmission and rain margin in transmissions between two stations of the system which are experiencing either one of a fade or non-fade condition, the method comprising the steps of:

• at a transmitting station
• (a) encoding a message burst signal using a first pair combination of a predetermined redundancy code of a plurality of redundancy codes and a predetermined signal constellation of a plurality of signal constellations and transmitting said encoded message burst signal in a single time slot of the frame sequence when the transmission between the transmitter and the remote receiver destined to receive the message burst signal is equal to or greater than a predetermined carrier-to-noise ratio (CNR), where each signal constellation of the plurality of signal constellations comprises a plurality of points and is not a scalar replica of another signal constellation;
• and
• (b) encoding a message burst signal using a second pair combination of a predetermined redundancy code of a plurality of redundancy codes and a predetermined signal constellation of a plurality of signal constellations and transmitting said encoded message burst signal once in more than one time slot of the TDMA frame sequence when the transmission between the transmitter and the remote receiver destined to receive the message burst signal is below the predetermined CNR, where the first pair combination and the second pair combination are a different pair of the plurality of redundancy codes and the plurality of signal constellations.