Simultaneous transmit signals and receive signals
Simultaneous transmit signals and receive signals (STAR) circuit and method includes: an error correction circuit for receiving a receive signal and a transmit signal for transmission; a first input port for receiving the transmit signal; a second input port for receiving a modification signal; and an adder to add the transmit signal to the modification signal to generate a modified modification signal, wherein the modified modification signal is input to the error correction circuit, wherein the modification signal modifies the transmit signal to have energy orthogonal to the receive signal, and wherein the transmit signal is transmitted simultaneously with receiving the receive signal.
1 . A simultaneous transmit and receive (STAR) circuit comprising:
a receiver to receive an input signal from a distant source and that also receives a locally transmitted (self) signal, wherein the locally transmitted (self) signal is an output of the STAR circuit that is created based on an internal transmitted signal, wherein the receiver adds the locally transmitted (self) signal to the input signal and produces a receiver signal;
an estimated self-transmission response circuit that receives the locally transmitted signal and creates an estimate of the locally transmitted (self) signal, wherein the locally transmitted (self) signal is transmitted by the STAR circuit simultaneously with the receiver receiving the input signal, wherein the locally transmitted (self) signal is a convolution of the internal transmitted signal with an impulse response of the estimated self-transmission response circuit;
an adder that removes the estimate of the locally transmitted (self) signal from the receiver signal to produce an estimated distance source signal;
a means for creating a modification signal;
a modification signal adder that adds the modification signal to the internally transmitted signal to generate a modified modification signal, wherein the modification signal modifies the estimated transmitted signal to have energy orthogonal to the distant source signal to reduce short-term correlation between the modified modification signal and the distant source signal and thereby improve convergence of the self transmission estimate;
a correlator that creates an adjustment signal, wherein the correlator creates the adjustment signal from the estimated distance source signal and the modified modification signal; and
an estimated self-transmission response circuit that creates the estimate of the self transmission signal based on the internal transmitted signal and the adjustment signal.
2 . The STAR circuit of claim 1 , wherein the modification signal eliminates short-term fluctuations in correlation between the transmitted signal and the modification signal.
3 . The STAR circuit of claim 1 , wherein the correlator performs correlation and adaptation as a block process.
4 . The STAR circuit of claim 1 , wherein the transmitted and modification signals are vectorized similarly in such a manner that a magnitude of a vector of the modification signal is minimized.