Cell quality measurements for cellular IOT systems
Systems, apparatuses, methods, and computer products for cell quality measurements of for cellular internet of things (IOT) systems provided, including for cellular narrow-band IOT (NBIOT) systems and machine type communication (MTC) systems. For example, an IOT device may determine these cell quality measurements to select a serving cell to use for connecting to a cellular network. The cell quality measurements may include channel estimation that is used to generate an RSRP, RSRQ, and Noise Variance estimation. In various embodiments, and based on the cell quality measurements, an IOT device may rank a plurality of cells and select a top ranked cell for providing cellular service.
1 . A user equipment comprising:
an antenna;
a modem for a cellular internet of things (IoT) network, wherein the modem is configured to:
receive, at the modem from the antenna, a first cellular signal from a first cell of one or more cells;
convert, at the modem, the first cellular signal to a first frequency domain signal;
generate, based on the first frequency domain signal, a first channel estimation and a first Received Signal Strength Indicator (RSSI), wherein generating the first channel estimation is based on a least squares estimation, a smoothing channel filter, and a time-domain average; and
determine, based on the first channel estimation, a first noise variance, a first Reference Signal Received Power (RSRP), a first Reference Signal Received Quality (RSRQ), and a first Signal-to-Interference plus Noise Ratio (SINR).
2 . The user equipment of claim 1 , wherein the modem is further configured:
select the first cell based on the first RSRP, the first RSRQ, and the first SINR.
3 . The user equipment of claim 1 , wherein the modem, to generate the first channel estimation based on the least squares estimation, the smoothing channel filter, and the time-domain average, is further configured to:
determine the least squares estimation based on the first frequency domain signal;
apply the smoothing channel filter to the least squares estimation to generate a smoothed least squares estimation; and
time-domain average the smoothed least squares estimation to generate the first channel estimation.
4 . The user equipment of claim 1 , wherein the modem, to determine, based on the first channel estimation, the first noise variance, the first RSRP, the first RSRQ, and the first SINR, is further configured to:
determine, based on the first channel estimation and the first frequency domain signal, the first noise variance;
determine, based on the first channel estimation, the first RSRP;
determine, based on the first RSSI and the first RSRP, the first RSRQ; and
determine, based on the first noise variance and the first RSRP, the first SINR.
5 . The user equipment of claim 1 , wherein the modem is further configured to:
receive, at the modem from the antenna, a second cellular signal from a second cell;
convert, at the modem, the second cellular signal from the second cell to a second frequency domain signal;
determine, based on the second frequency domain signal, a second channel estimation and a second RSSI;
determine, based on the second frequency domain signal and the second channel estimation, a second noise variance;
determine, based on the second channel estimation, a second RSRP;
determine, based on the second RSSI and the second RSRP, a second RSRQ; and
determine, based on the second noise variance and the second RSRP, a second SINR.
6 . The user equipment of claim 5 , wherein the modem is further configured to:
perform a cell reselection process based on the first RSRP, the first RSRQ, the first SINR, the second RSRP, the second RSRQ, and the second SINR.
7 . The user equipment of claim 6 , wherein the modem, to perform a cell reselection process, is further configured to:
rank the first cell and second cell based on the first RSRP, the first RSRQ, the first SINR, the second RSRP, the second RSRQ, and the second SINR; and
select a highest rank cell of the first cell and the second cell.
8 . The user equipment of claim 1 , wherein the modem, to apply a smoothing channel filter to the least squares estimation, is further configured to:
segment the least squares estimation into a plurality of segments; and
apply the smoothing channel filter to each segment of the plurality of segments.
9 . The user equipment of claim 1 , wherein the modem is a narrow-band IoT (NBIOT) modem.
10 . The user equipment of claim 1 , wherein the modem is a machine type communication (MTC) modem.
11 . A method for determining cell quality measurements, the method comprising:
receiving, at a modem, a first cellular signal from a first cell of one or more cells;
converting, at the modem, the first cellular signal from the first cell to a first frequency domain signal;
generating, based on the first frequency domain signal, a first channel estimation and a first Received Signal Strength Indicator (RSSI), wherein generating the first channel estimation is based on a least squares estimation, a smoothing channel filter, and a time-domain average;
determining, based on the first channel estimation, a first noise variance, a first Reference Signal Received Power (RSRP), a first Reference Signal Received Quality (RSRQ), and a first Signal-to-Interference plus Noise Ratio (SINR).
12 . The method of claim 11 further comprising:
selecting the first cell based on the first RSRP, the first RSRQ, and the first SINR.
13 . The method of claim 11 , wherein generating, based on the first frequency domain signal, a first channel estimation and a first RSSI, wherein determining the first channel estimation is based on a least squares estimation, a smoothing channel filter, and a time-domain average comprises:
determining a least squares estimation based on the first frequency domain signal;
applying a smoothing channel filter to the least squares estimation to generate a smoothed least squares estimation;
time-domain averaging the smoothed least squares estimation to generate the first channel estimation.
14 . The method of claim 11 , wherein determining, based on the first channel estimation, the first noise variance, the first RSRP, the first RSRQ, and the first SINR comprises:
determining, based on the first channel estimation and the first frequency domain signal, the first noise variance;
determining, based on the first channel estimation, the first RSRP;
determining, based on the first RSSI and the first RSRP, the first RSRQ; and
determining, based on the first noise variance and the first RSRP, the first SINR.
15 . The method of claim 11 further comprising:
receiving, at the modem, a second cellular signal from a second cell;
converting, at the modem, the second cellular signal from the second cell to a second frequency domain signal;
determining, based on the second frequency domain signal, a second channel estimation and a second RSSI;
determining, based on the second frequency domain signal and the second channel estimation, a second noise variance;
determining, based on the second channel estimation, a second RSRP;
determining, based on the second RSSI and the second RSRP, a second RSRQ; and
determining, based on the second noise variance and the second RSRP, a second SINR.
16 . The method of claim 15 further comprising:
performing a cell reselection process based on the first RSRP, the first RSRQ, the first SINR, the second RSRP, the second RSRQ, and the second SINR.
17 . The method of claim 16 , wherein performing the cell reselection process comprises:
ranking the first cell and second cell based on the first RSRP, the first RSRQ, the first SINR, the second RSRP, the second RSRQ, and the second SINR; and
selecting a highest rank cell of the first cell and the second cell.
18 . The method of claim 11 , wherein applying a smoothing channel filter to the least squares estimation comprises:
segmenting the least squares estimation into a plurality of segments; and
applying the smoothing channel filter to each segment of the plurality of segments.
19 . The method of claim 11 , wherein the modem is a narrow-band IoT (NBIOT) modem or a machine type communication (MTC) modem.
20 . A modem comprising at least one processor and at least one memory coupled to the at least one processor, wherein the at least one processor is configured to;
receive, at the modem from an antenna, a first cellular signal from a first cell of one or more cells;
convert, at the modem, the first cellular signal to a first frequency domain signal;
generate, based on the first frequency domain signal, a first channel estimation and a first Received Signal Strength Indicator (RSSI), wherein generating the first channel estimation is based on a least squares estimation, a smoothing channel filter, and a time-domain average; and
determine, based on the first channel estimation, a first noise variance, a first Reference Signal Received Power (RSRP), a first Reference Signal Received Quality (RSRQ), and a first Signal-to-Interference plus Noise Ratio (SINR).