Abstract: Certain aspects of the present disclosure relate to a technique for two-step joint demapping based on sphere decoding for log-likelihood ratio (LLR) computation related to a received multiple-input multiple-output (MIMO) signal. The first step of the proposed algorithm comprises a linear minimum mean square error (LMMSE) based detection to form soft symbol estimates of symbols being transmitted. Then, the LMMSE-based soft symbol estimates can be utilized to form a set of constellation points of a stream interfering to a stream of interest. These candidate constellation points can be then subtracted (canceled) from the received signal to improve the LLR computations of the stream of interest. After the cancellation, the maximum ratio combining (MRC) can be applied to each individual stream to form more refined soft symbol estimates as well as an effective signal-to-noise ratio (SNR) estimate.

Abstract: A low complexity List Viterbi algorithm (LVA) for decoding tail biting convolutional codes (TBCCs) has lower complexity than a solution of running the LVA algorithm for all states. In one aspect, a low complexity LVA-TBCC process includes finding a list of states from a single Viterbi algorithm and finding a list of potential codewords for each state in the state list using the LVA. A cyclic redundancy check may prune out false solutions. The disclosed method may be applied to many communication systems to improve error performance similar to LTE downlink PBCH decoding enhancements.

Abstract: Techniques for supporting peer-to-peer (P2P) communication and wide area network (WAN) communication are disclosed. In one aspect, P2P communication may be supported on an uplink spectrum. A user equipment (UE) may communicate (i) with a base station on both a downlink spectrum and an uplink spectrum for WAN communication and (ii) with another UE on only the uplink spectrum for P2P communication. In another aspect, P2P communication may be supported by time division multiplexing the downlink and uplink (or transmit and receive links) for two UEs. In yet another aspect, WAN communication and P2P communication may be time division multiplexed, so that both can be concurrently supported by a UE. In yet another aspect, transmission gaps may be provided between WAN transmissions and P2P transmissions in order to avoid interference between these transmissions.

Abstract: Techniques for transmitting UE-specific reference signals (UE-RSs) in a wireless network are described. In an aspect, a UE-RS may be transmitted in different manners depending on the number of layers used for data transmission. In one design, a cell may determine subcarriers for a UE-RS based on a frequency shift if data is transmitted on one layer and based on a predetermined set of subcarriers (with no frequency shift) if data is transmitted on multiple layers. In another aspect, a UE-RS may be transmitted on subcarriers determined based on a frequency shift for data transmission on multiple layers. In yet another aspect, a UE-RS may be transmitted from a plurality of cells to a UE for coordinated multi-point (CoMP). In yet another aspect, a UE-RS may be transmitted in a data section of a subframe including only the data section.

Abstract: Systems and methodologies are described that facilitate controlling interference in a heterogeneous wireless communication environment. A Physical Broadcast Channel (PBCH) transmission from an interfering base station can be punctured based upon a puncturing pattern as a function of a cell identifier (ID) and a transmit time. Puncturing can be effectuated by applying power control. Thus, a punctured symbol or subframe can have a reduced transmit power or a transmit power set to zero. Further, the puncturing pattern can be defined on a subframe basis or on a symbol basis.

Abstract: Reliability metric(s), based on output of a decoder module, associated with each possible hypothesis associated with blind decoding are provided that aids a pruning process by rejecting unreliable CRC-passed hypotheses. In an aspect, a downlink control channel carries scheduling assignments and other control information. As location, size, and CRC masking associated with downlink control information are not known to a receiver, blind decoding over possible hypotheses may be performed. The complex structure of the downlink control channel blind decoding results in increasing false alarm(s). Intelligent rules for pruning the decoding results are employed so that unreliable CRC-passed hypotheses are rejected as a function of respective reliability metric.

Abstract: An apparatus and method for establishing a relay transition time in a network node in a wireless communication system comprising comparing a network node transmit/receive (TX/RX) switch time to a switch threshold; and using a fraction of the cyclic prefix (CP) as a guard period if the network node TX/RX switch time is less than or equal to the switch threshold, or using a sounding reference signal (SRS) configured channel to blank out a last symbol if the network node TX/RX switch time is greater than the switch threshold.

Abstract: An apparatus and method for communicating information in a relay downlink backhaul between a base station and at least one relay node comprising: determining a first starting symbol index of at least one control channel in the relay downlink backhaul; determining a second starting symbol index of at least one data channel in the relay downlink backhaul; and communicating information using the at least one control channel based on the first starting symbol index and the at least one data channel based on the second starting symbol index in the relay downlink backhaul. In one example, the apparatus and method comprise receiving information using a control channel based on a first starting symbol index and a data channel based on a second starting symbol index in the relay downlink backhaul.

Abstract: Systems and methodologies are described that facilitate precoding signals transmitted over downlink control channels to provide transmit diversity. A dedicated reference signal (DRS) related to a wireless device can additionally be precoded such that the wireless device can determine a precoder or related parameters based at least in part on performing a channel estimate for the precoded DRS signal. The wireless device can utilize the determined precoder or related parameters to decode precoded signals received over downlink control channel resources. Additionally or alternatively, an access point can signal a sequence of precoders to the wireless device. The access point can cycle through the sequence of precoders to precode signals for transmission over downlink control channel resources, and the wireless device can decode the signals based at least in part on similarly cycling through the precoders for received signals.

Abstract: Aspects of the present disclosure describe an efficient channel estimation algorithm for high-speed processing of dedicated reference signals. The channel estimation algorithm may utilize one or more compressed interpolation matrices. The compressed interpolation matrices may be selected based on the Doppler value and signal to noise ratio (SNR) of the channel.

Abstract: Methods, systems, apparatus and computer program products are provided to improve synchronization of information units communicated in a wireless communication system. Timing misalignment in the transmission of adjacent information units can produce gaps or overlaps in the transmitted information. In a long-term evolution (LTE) wireless communication system, such gaps and overlaps can be eliminated or reduced by adjusting the lengths of a cyclic prefix portion of one or more transmitted symbols. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the disclosed subject matter. Therefore, it is to be understood that it should not be used to interpret or limit the scope or the meaning of the claims.