Abstract:
PROBLEM TO BE SOLVED: To provide systems and methods that facilitate signaling and detecting discontinuous transmission (DTX) in a wireless communication environment.SOLUTION: A DTX indicator and channel quality indicator (CQI) feedback can be multiplexed within a common uplink control channel subframe and transmitted to a base station when an access terminal is operating in a DTX mode for an acknowledgement channel. Further, when operating in a non-DTX mode, the access terminal can multiplex an ACK indicator or a NAK indicator with the CQI feedback within a common uplink control channel subframe, which can thereafter be transferred to the base station. Accordingly, the base station can detect DTX operation or non-DTX operation of the access terminal.
Abstract:
PROBLEM TO BE SOLVED: To provide a technique for an improved demodulation process that considers thermal noise for one or more antennas mounted on a receiver, regarding noise variance estimation in wireless communications. SOLUTION: Noise variance estimation includes: receiving a signal including an OFDM symbol having in-band tones including in-band pilot tones and band-edge tones including band-edge pilot tones and guard tones; estimating an equivalent noise variance for the in-band tones using the in-band pilot tones and channel estimates for the in-band pilot tones; and estimating an equivalent noise variance for the band-edge tones using the band-edge pilot tones, channel estimates for the band-edge pilot tones, and the guard tones. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To enhance uplink (UL) coverage in interference scenarios.SOLUTION: The invention relates to communication in a wireless network in which user equipment (UE) associated with a first evolved Node B (eNB) experiences interference from a second eNB. The first eNB of the wireless network and a second eNB of the wireless network negotiate for partitioning of subband resources on an uplink. A first subset of the subband resources is assigned to the first eNB, and a second subset of the subband resources is assigned to the second eNB. The user equipment (UE) determines an uplink subframe n containing a protected subband for uplink transmission, decodes a downlink control channel received during a protected downlink subframe, and transmits data during the uplink subframe n on the protected subband.
Abstract:
PROBLEM TO BE SOLVED: To provide techniques for efficiently deriving uplink channel estimates without consuming too much special uplink resources.SOLUTION: UE 120 sends a request for uplink resources on a request channel (REQCH) whenever the UE transmits data on the uplink. The UE sends, from multiple antennas, REQCH data on data subcarriers and a pilot on pilot subcarriers. A Node B 110 receives the request, estimates the complex channel gains for the pilot subcarriers on the basis of received pilot symbols, and coherently demodulates received data symbols on the basis of the channel gain estimates. The Node B estimates the complex channel gains for the data subcarriers on the basis of demodulated data symbols, and derives a channel estimate for each antenna on the basis of the channel gain estimates for the pilot and data subcarriers.
Abstract:
PROBLEM TO BE SOLVED: To facilitate pilot signal design, power control, data rate determination, and channel assignment in the reverse link of a wireless communication system for dynamic scheduling and joint operation in SIMO, SU-MIMO, and MU-MIMO.SOLUTION: Transmission of pilot signals is based on periodic transmissions of multiple sounding reference sequences. Power control is based on a reference signal at a predetermined power spectral density (PSD) level, and on an offset PSD determined and signaled based on an antenna that transmits the reference signal, other cell interference, and power amplifier headroom. PSD levels for SIMO/MIMO data transmissions are determined based on channel estimates and the predetermined PSD and offset PSD. Communication resources are conveyed through a channel assignment with an overhead that depends on the maximum multiplexing order of the estimated channel.
Abstract:
PROBLEM TO BE SOLVED: To provide a method of applying PAR back-off values to determine the transmission power and rate for SIMO and MIMO.SOLUTION: A power allocation algorithm for different UL MIMO schemes is described as follows. For MIMO without antenna permutation, different PAR back-off values are considered for different data streams. For MIMO with antenna permutation or other unitary transformation such as virtual antenna mapping or precoding, the PAR back-off values are determined based on a combined channel.