Abstract: Massive MU-MIMO employs thousands of antennas at the base station. The number of antennas required to serve users vary from time to time as the number and profile of users change, affecting the operational efficiency of the base station. The embodiments presented here is a computationally efficient heuristic method and system components at the next generation base station transmitter that selects best set of antennas, limited by the total number of transmitter RF chains, and the corresponding prioritized set of users to be served by a time-frequency radio resource at time t. The method starts by selecting a group of antennas, and prioritizing users for that group using channel state information (CSI), and then by iteratively or concurrently adding (or deleting) antennas, and correspondingly by adding (or deleting) users at each step using a method to jointly solve the problem of selecting antennas and prioritizing users.

Abstract: An apparatus and method for a base station (BS) in a cellular network for uplink (UL) Joint Reception of Coordinated Multi Point (JR-CoMP) operations, wherein the User Equipment (UE) sends to the serving and coordinating Radio Units (RUs) a first data block, wherein because of different channel qualities, first data block arriving as second data block at serving RU and as third data block at coordinating RU, respectively. The Baseband Unit (BBU) associated with these RUs using two nested HARQ processes: First, a ‘fake’ HARQ process to combine the separately channel processed second data block with the third data block; then, a real HARQ process to combine the fake HARQ-combined data block with the retransmitted first data block. Fake HARQ uses Chase Combining while real HARQ uses Incremental-Redundancy Combining.

Abstract: An apparatus and method for a base station (BS) in a cellular network for uplink (UL) Joint Reception of Coordinated Multi Point (JR-CoMP) operations, wherein the User Equipment (UE) sends to the serving and coordinating Radio Units (RUs) a first data block, wherein because of different channel qualities, first data block arriving as second data block at serving RU and as third data block at coordinating RU, respectively. The Baseband Unit (BBU) associated with these RUs using two nested HARQ processes: First, a ‘fake’ HARQ process to combine the separately channel processed second data block with the third data block; then, a real HARQ process to combine the fake HARQ-combined data block with the retransmitted first data block. Fake HARQ uses Chase Combining while real HARQ uses Incremental-Redundancy Combining.

Abstract: The non-linear behavior of power amplifier is linearized using a pre-distorter that is adaptive to changes in the behavior of the power amplifier and uses an artificial neural network. According to embodiments presented here, the pre-distorter's artificial neural network is model-trained from time to time to learn the inverse of the transfer function of the power amplifier by using a second pre-distorter modeling system. The second modeling system determines the parameters of the inverse of the transfer function of the power amplifier using a least square method by using the (un-distorted) output signal samples of the power amplifier. Using the output of the second system as output to train the neural network enables the neural network to more successfully linearize the power amplifier's behavior. Furthermore, the trained artificial neural network as the pre-distorter can be implemented in hardware and presents a small form factor.

Abstract: According to aspects of the disclosure, a multi-feed multi-band MIMO antenna system comprises at least two antennas orthogonally positioned with respect to each other, which are operating over two different frequency ranges; at least two out-of-band resonators coupled with the two antennas respectively; and, at least two other in-band resonators coupled with the two antennas respectively and designed to decrease mutual coupling in the frequency ranges, where the first resonator filters out signals having the second frequency range leaking into a first antenna, while the second resonator filters out other signals having the first frequency range leaking into a second antenna.

Abstract: According to aspects of the disclosure, a multi-feed multi-band MIMO antenna system comprises at least two antennas orthogonally positioned with respect to each other, which are operating over two different frequency ranges; at least two out-of-band resonators coupled with the two antennas respectively; and, at least two other in-band resonators coupled with the two antennas respectively and designed to decrease mutual coupling in the frequency ranges, where the first resonator filters out signals having the second frequency range leaking into a first antenna, while the second resonator filters out other signals having the first frequency range leaking into a second antenna.