Showing papers on "Zero-forcing precoding published in 1987"
TL;DR: The capacity region of the discrete memoryless interference channel with strong interference has been established and the capability of the channel to handle strong interference is established.
Abstract: The capacity region of the discrete memoryless interference channel with strong interference is established.
324 citations
Book•
01 Jan 1987
36 citations
Patent•
27 Nov 1987TL;DR: In this paper, an interference nulling system is provided which nulls out all types of interference signals received in different lobes of the receiving antenna, where the interference signals in this latter channel are correlated with the interference components in the data channel.
Abstract: An interference nulling system is provided which nulls out all types of interference signals received in different lobes of the receiving antenna. The data to be received is transmitted from a high quality circular polarized transmitter antenna having the same polarization as the data receiving port of the receiving antenna. The receiving antenna also has a receiving port whose circular polarization is orthogonal to the antenna port receiving the data so that this latter channel contains only interference signals. The interference signals in this latter channel are correlated with the interference components in the data channel. A control loop is employed to adaptively adjust the phase (or delay) and amplitude of the sample of the interference signal and the adaptively adjusted interference signal is subtracted from the data signal which contains some of the interference signals, thus, providing a clean data signal.
20 citations
TL;DR: It is shown that when the interference is near the signal, other random noise that is present, even if it is small in amplitude, may be amplified by the AOAF's, so that even though the coherent interference is rejected, the total signal-to-noise ratio is reduced.
Abstract: A recent paper [1] described a set of array filters referred to as absolutely optimal array filters (AOAF's) to achieve the rejection of an interference from the output of an array in order to allow observation of the signal. The array filters resulted in perfect rejection of the interference while achieving an all-pass response to the signal regardless of how close to the signal the interference occurs. However, they were developed by neglecting the presence of random noise at the sensor outputs, that is, assuming that only the interference is masking the signal. In reality, there is almost always additional noise present, even though it may be relatively small in amplitude relative to the interference. It is widely known that this noise cannot be ignored. For the important case of an array with plane wave signal and interference, it is shown that when the interference is near the signal, other random noise that is present, even if it is small in amplitude, may be amplified by the AOAF's, so that even though the coherent interference is rejected, the total signal-to-noise ratio is reduced.
1 citations