Ways to strengthen the weak spread spectrum signal to cancel a strong signal
(57) The invention provides a method for enhancing the tracking capability of the strong signal interference determined weak signal in the CDMA coded spread spectrum radio signal to the received weak signal including the intensity signal. A two signals modulation code is known to predict the weak signal. For strong signal strength and strong signals and weak signal determining an interference strength signal as a product (40) between the predicted strong signal interference (50). Measuring the intensity signals from both methods, it is possible to predict or obtain (10). It is possible to predict the cross-correlation with respect to the weak signal is selected as the predicted value for maximum reception strength range of weak signal value (60).
We consider the MIMO wiretap channel, that is a MIMO broadcast channel where the transmitter sends some confidential information to one user which is a legitimate receiver, while the other user is an eavesdropper. Perfect secrecy is achieved when the transmitter and the legitimate receiver can communicate at some positive rate, while insuring that the eavesdropper gets zero bits of information. In this paper, we compute the perfect secrecy capacity of the multiple antenna MIMO broadcast channel, where the number of antennas is arbitrary for both the transmitter and the two receivers. Our technique involves a careful study of a Sato-like upper bound via the solution of a certain algebraic Riccati equation.