Abstract: A method implemented in a user equipment used in a wireless communications system is disclosed. The method comprises receiving from a base station an indication of a first modulation type for the user equipment, receiving from the base station a first data signal for the user equipment, receiving from the base station an indication of a minimum time-frequency unit that is assigned to another user equipment, receiving a second data signal for said another user equipment, where a second modulation type for said another user equipment is unknown to the user equipment, and cancelling and suppressing interference by using the minimum time-frequency unit. Other methods, systems, and apparatuses also are disclosed.

Abstract: A method implemented in a mobile communications network supporting coordinated multiple point transmission and reception (CoMP) is disclosed. The method includes transmitting, to a user equipment (UE), data in a physical downlink shared channel (PDSCH), and transmitting a reference signal to the UE, wherein a union of resource elements (REs) allocated for reference signals transmitted from a subset of a plurality of transmission points (TPs) in a CoMP set are excluded from resource mapping for transmitting the data to the UE. Other methods, systems, and apparatuses also are disclosed.

Abstract: A method implemented in a user equipment used in a multi-user multiple input multiple output (MU-MIMO) wireless communications system is disclosed. The method includes receiving from a base station an indication of a first modulation type for the user equipment, receiving a first data signal for the user equipment, receiving a second data signal for a co-scheduled user equipment, where a second modulation type for the co-scheduled user equipment is unknown to the user equipment, and deciding the second modulation type. Other methods, systems, and apparatuses also are disclosed.

Abstract: A wireless communications system is disclosed. The system comprises a baseband processing unit (BBU) pool including one or more baseband processing units (BBUs), and a plurality of remote radio heads (RRHs) connected to the BBU pool through a front-haul network, wherein the wireless communications system has a plurality of sectors, each of which includes one or more small cells, each of which is deployed by one of the plurality of RRHs, wherein a BBUs is mapped to two or more RRHs in a sector in a one-to-many configuration, and a BBU is mapped to a single RRH in a sector in a one-to-one configuration, and wherein a combination of the one-to-one configuration and the one-to-many configuration is applied to each sector. Other systems, apparatuses, and methods also are disclosed.

Abstract: A user equipment (UE) used in a multi-user (MU)-multiple input multiple output (MIMO) orthogonal frequency division multiple access (OFDMA) system is disclosed. The UE includes a receiving unit to receive from a base station an indication of an estimate of or an upper-bound on the total number of MU-MIMO user equipments (|S|) that are scheduled on a sub-band by the base station, wherein the sub-band includes one or more resource units, a calculation unit to calculate channel quality based on the indication of the estimate of or the upper-bound on the total number of MU-MIMO user equipments, and a transmission unit to transmit to the base station an indication of the channel quality. Other methods and apparatuses also are disclosed.

Abstract: A communications method implemented in a transmission point (TP) used in a coordinated multipoint transmission and reception (CoMP) system is disclosed. The communications method comprises transmitting, to a user equipment (UE), attributers for up to four indicators indicating at least physical downlink shared channel (PDSCH) resource element (RE) mapping, and transmitting, to the UE, one of the four indicators, each of which is conveyed in 2 bits, wherein the four indicators comprises ‘00’, ‘01’, ‘10’, and ‘11’ corresponding to a first set, a second set, a third set, and a fourth set of parameters, respectively. Other methods, apparatuses, and systems are also disclosed.

Abstract: Methods and systems for conveying or transmitting to any given user in an OFDMA-MU-MIMO system scheduling information of other co-scheduled users to permit the user to perform error-correction on received data and/or interference reduction on its received signals. The scheduling information can include resource block assignment, modulation constellations employed, coding rates employed, power levels utilized and precoder matrix indices used. Further, the scheduling information can be conveyed in part through dedicated reference symbol layers or pilot streams. Moreover, a base station may transmit a preliminary estimate of the total number of users the base station expects to schedule, or an upper-bound on the total number of users, to the MU-MIMO users to permit the MU-MIMO users to determine preferred precoder matrix indices and indications of channel quality indices.

Abstract: A method implemented in a user terminal is disclosed. The method comprises obtaining known precoding matrix P of rank r and modulation and coding scheme assignments used in an original transmission, and a desired retransmission rank r?, forming an approximate channel covariance matrix, estimating a minimum mean square error receiver SINR for each layer to be retransmitted responsive to said forming, and finding a retransmission precoding matrix from a preceding codebook that maximizes a sum-rate for enabling precoding selections for retransmissions in uplink multiple-input multiple-output MIMO hybrid automatic repeat request HARQ. Other methods, apparatuses, and systems also are disclosed.

Abstract: A wireless communications method implemented in a network system that supports coordinated multipoint transmission and reception (CoMP) is disclosed. The wireless communications method includes informing a user equipment (UE) semi-statically of a codebook subset for each channel state information (CSI) process, wherein the UE is restricted to report an indication of a precoding matrix within the codebook subset. Other methods, apparatuses, and systems are also disclosed.

Abstract: A method implemented in a user equipment configured to be used in a multi-user (MU) multiple-input multiple-output (MIMO) wireless communications system is disclosed. The method includes transmitting to a base station a first channel state information (CSI) report determined according to a single-user (SU) MIMO rule, and transmitting to the base station a second CSI report determined according to an MU-MIMO rule. Other methods, apparatuses, and systems also are disclosed.

Abstract: A method includes obtaining a precoder for retransmission of one codeword responsive to known precoding matrix P of rank r and modulation and coding scheme MCS assignments used in an original transmission, and a desired retransmission rank r?; and scaling power in the retransmission responsive to at least two of 1) information parameters Index of UL precoder in previous transmission, 2) rank r of uplink UL precoder in previous transmission, 3) MCS assignments in previous retransmission (MCSi), 4) rank r? for UL retransmission 5) number of retransmit antennas used for codeword to be retransmitted x in previous transmission, 6) number of retransmit antennas x? used for retransmission, 7) precoder for UL retransmission, 8) UL precoders and channel information for previous transmission, and 8) latest channel measurements.

Abstract: A communications method implemented in a transmission point (TP) used in a coordinated multipoint transmission and reception (CoMP) system is disclosed. The communications method comprises transmitting, to a user equipment (UE), attributers for up to four indicators indicating at least physical downlink shared channel (PDSCH) resource element (RE) mapping, and transmitting, to the UE, one of the four indicators, each of which is conveyed in 2 bits, wherein the four indicators comprises ‘00’, ‘01’, ‘10’, and ‘11’ corresponding to a first set, a second set, a third set, and a fourth set of parameters, respectively. Other methods, apparatuses, and systems are also disclosed.

Abstract: A method for determining attributes of communication channels of multi-user (MU)-multiple input multiple output (MIMO) users in an orthogonal frequency division multiplexing based multiple access (OFDMA) system is disclosed. The method comprises receiving from a base station, for at least one sub-band of contiguous sub-carriers, an indication of an estimate of or an upper-bound on a total number of streams that are co-scheduled by the base station on the at least one sub-band or an indication of a fraction of a transmit power at the base station that is applied to streams that are scheduled for transmission to a particular user, determining one or more signal quality measures for the at least one sub-band based on at least one of the fraction or the estimate of or the upper-bound on the total number of streams that are scheduled by the base station on the at least one sub-band, and transmitting to the base station an indication of the one or more signal quality measures.

Abstract: A method implemented in a user equipment used in a multi-user multiple input multiple output (MU-MIMO) wireless communications system is disclosed. The method includes receiving from a base station an indication of a first modulation type for the user equipment, receiving a first data signal for the user equipment, receiving a second data signal for a co-scheduled user equipment, where a second modulation type for the co-scheduled user equipment is unknown to the user equipment, and deciding the second modulation type. Other methods, systems, and apparatuses also are disclosed.

Abstract: A method implemented in a user terminal is disclosed. The method comprises obtaining known precoding matrix P of rank r and modulation and coding scheme assignments used in an original transmission, and a desired retransmission rank r?, forming an approximate channel covariance matrix, estimating a minimum mean square error receiver SINR for each layer to be retransmitted responsive to said forming, and finding a retransmission precoding matrix from a preceding codebook that maximizes a sum-rate for enabling precoding selections for retransmissions in uplink multiple-input multiple-output MIMO hybrid automatic repeat request HARQ. Other methods, apparatuses, and systems also are disclosed.

Abstract: A method implemented in a user equipment configured to be used in a multi-user (MU) multiple-input multiple-output (MIMO) wireless communications system is disclosed. In an aspect, the user equipment transmits to a base station a first channel state information (CSI) report determined according to a single-user (SU) MIMO rule and a second CSI report determined according to an MU-MIMO rule.

Abstract: A method implemented in a user equipment configured to be used in a multi-user (MU) multiple-input multiple-output (MIMO) wireless communications system is disclosed. In an aspect, the user equipment transmits to a base station a first channel state information (CSI) report determined according to a single-user (SU) MIMO rule and a second CSI report based on a residual error.

Abstract: A method for improving multiple-input multiple-output MIMO downlink transmissions includes obtaining a channel state information CSI report including preferred matrix index PMI for precoding, channel quality index CQI and rank index RI at a base station from user terminals through a channel feedback; applying selectively a signal-to-interference-plus-noise-ratio SINR offset to a SINR of said CSI report; applying selectively a rate matching responsive to SINR offset or the CSI report; and controlling or adjusting the SINR offset.

Abstract: A method of uplink resource allocation is disclosed. The method includes computing a set of utilities for each of a finite set of transmission modes with a processor across a plurality of user devices, each having multiple transmit antennas, and iteratively allocating uplink resource blocks (RBs) and transmission modes to the plurality of user devices until all users have been allocated or no allocation is found, by selecting a mode that has a highest incremental utility sum for each user across one or more RBs, determining which user has the highest incremental utility sum, allocating the mode and RBs associated with the highest incremental utility sum to the user, and removing the allocated user from consideration. Other apparatuses, systems, and methods also are disclosed.

Abstract: A method implemented in a user equipment used in a multi-user multiple input multiple output (MU-MIMO) wireless communications system is disclosed. The method includes receiving from a base station an indication of a first modulation type for the user equipment, receiving a first data signal for the user equipment, receiving a second data signal for a co-scheduled user equipment, where a second modulation type for the co-scheduled user equipment is unknown to the user equipment, and deciding the second modulation type. Other methods, systems, and apparatuses also are disclosed.