Method for the separation of packets of information involved in colisu00d5es occurred when two or more senders transmit to a release base at the same time interval in telecommunications systems based on OFDM access aleatu00d3rio

摘要

The methods presented together with the corresponding emission and reception devices aimed at maximizing the throughput in telecommunication systems based on ofom (modulation technique that uses multiple orthogonal subportadoras) through the efficient separation of packages in The occurrence of collisions.Through the use of some subportadoras and periods of time reserved specifically for the transmission of pilot symbols (106) for each user device, it is possible to base station determine whether there was a collision of packets (206) and request retransmissions of the same to disp Ositivos users involved.To allow a more reliable separation of the packages (207) in the receiver, the devices users apply interlau00e7adores of different symbols (104) at each retransmission in order to take advantage of the characteristics of multi - path channel in the frequency domain in the system. S OFDM.The total number of transmissions needed to carry out the separation of packets is equal to the number of packages has faced. The receiver awaits the receipt of all the relays and then separating the packages (207) using detection techniques typically used in systems with multiple antennas in the spatial multiplexing transmission and reception (MIME).The scheme of receipt is iterative, so as to improve the separation of the cyclically packages (207), the estimation of the channel (214) and decoding (210) to obtain estimates of logarithms of ratios of probabilities of verisimilitude (LLRs) of the bits of the code and the bits of I. Nformau00e7u00e3o.