Reference signal presence and/or bandwidth determination in narrowband systems

A method for wireless communications by a base station (BS) for communication with a user equipment (UE) operating in a narrowband region of a wider system bandwidth, comprising:

• determining a presence of one or more downlink reference signals (RS) in a subframe and a bandwidth of the one or more downlink RS, wherein the bandwidth of the one or more downlink RS is greater than or equal to a bandwidth of the narrowband region, the narrowband region comprising six or less resource blocks (RBs);
• and
• transmitting the one or more downlink RS in the subframe based on the determination;
• determining one or more parameters for transmitting to the UE at least one of:
• system information, a paging message, a random access response (RAR) message, or a radio resource control (RRC) configuration message based, at least in part, on the determination of the presence of one or more downlink RS in a subframe and the bandwidth of the one or more downlink RS;
• and
• transmitting the at least one of:
• the system information, the paging message, the RAR message, or the RRC configuration message according to the determined one or more parameters, wherein the one or more parameters comprise at least one of:
• a frequency location, a time location, a repetition level, a Radio Network Temporary Identifier (RNTI), or a transmission mode comprising a demodulation reference signal (DMRS) based transmission mode or a cell-specific reference signal (CRS) based transmission mode;
• communicating with the UE using the DMRS based transmission mode using a first set of resources if the UE is a first type of UE;
• and
• communicating with the UE using the CRS based transmission mode using a second set of resources if the UE is a second type of UE.

An apparatus for wireless communications by a user equipment (UE) operating in a narrowband region of a wider system bandwidth, comprising:

• means for determining a presence of one or more downlink reference signals (RS) in a subframe and a bandwidth of the one or more downlink RS, wherein the bandwidth of the one or more downlink RS is greater than or equal to a bandwidth of the narrowband region, the narrowband region comprising six or less resource blocks (RBs);
• and
• means for monitoring for the one or more downlink RS in the subframe based on the determination;
• means for determining one or more parameters for receiving at least one of:
• system information, a paging message, a random access response (RAR) message, or a radio resource control (RRC) configuration message based, at least in part, on the determination of the presence of one or more downlink RS in a subframe and the bandwidth of the one or more downlink RS;
• and
• means for monitoring for the at least one of:
• the system information, the paging message, the RAR message, or the RRC configuration message according to the determined one or more parameters;
• wherein the one or more parameters comprise at least one of:
• a frequency location, a time location, a repetition level, a Radio Network Temporary Identifier (RNTI), or a transmission mode comprising a demodulation reference signal (DMRS) based transmission mode or a cell-specific reference signal (CRS) based transmission mode.

An apparatus for wireless communications by a base station (BS) for communication with a user equipment (UE) operating in a narrowband region of a wider system bandwidth, comprising:

• means for determining a presence of one or more downlink reference signals (RS) in a subframe and a bandwidth of the one or more downlink RS, wherein the bandwidth of the one or more downlink RS is greater than or equal to a bandwidth of the narrowband region, the narrowband region comprising six or less resource blocks (RBs);
• and
• means for transmitting the one or more downlink RS in the subframe based on the determination;
• means for determining one or more parameters for transmitting to the UE at least one of:
• system information, a paging message, a random access response (RAR) message, or a radio resource control (RRC) configuration message based, at least in part, on the determination of the presence of one or more downlink RS in a subframe and the bandwidth of the one or more downlink RS;
• means for transmitting the at least one of:
• the system information, the paging message, the RAR message, or the RRC configuration message according to the determined one or more parameters, wherein the one or more parameters comprise at least one of:
• a frequency location, a time location, a repetition level, a Radio Network Temporary Identifier (RNTI), or a transmission mode comprising a demodulation reference signal (DMRS) based transmission mode or a cell-specific reference signal (CRS) based transmission mode;
• means for communicating with the UE using the DMRS based transmission mode using a first set of resources if the UE is a first type of UE;
• and
• means for communicating with the UE using the CRS based transmission mode using a second set of resources if the UE is a second type of UE.