# US 2018/0026760 A1 · Channel identification in a mimo telecommunications system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0026760 A1 - Document ID: US20180026760A1 - Status: Published application - Kind: A1 - Application number: 15/549,057 - Filed: 2016-01-26 - Published: 2018-01-25 - Earliest claimed: 2015-02-11 - Assignees: CommScope Technologies LLC - Applicants: CommScope Technologies LLC - Inventors: Zhao Li - Web page: https://patentgrep.com/patent/US20180026760A1 ## CPC - H04L 5/005: {of common pilots, i.e. pilots destined for multiple users or terminals} - H04B 7/0413: MIMO systems - H04J 11/0079: {Acquisition of downlink reference signals, e.g. detection of cell-ID} - H04L 5/0023: {Time-frequency-space} - H04L 27/26: Systems using multi-frequency codes (H04L27/32 takes precedence) - H04L 27/2613: {Structure of the reference signals} - H04L 27/2655: {Synchronisation arrangements} - H04L 27/2692: {with preamble design, i.e. with negotiation of the synchronisation sequence with transmitter or sequence linked to the algorithm used at the receiver} - H04W 88/085: {Access point devices with remote components} - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04L 27/26136: {Pilot sequence conveying additional information} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04B: TRANSMISSION - H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A channel identification system and method are provided to automatically identify ports of a base station (e.g., an eNodeB) to route downlink signals to appropriate access points in a telecommunication system. Primary and secondary synchronization signals may be identified in the downlink signals transmitted by the base station. A broadcast channel may be decoded for a downlink signal including the primary and secondary synchronization signals. Signal information may be used to extract a first cell-specific reference signal and generate a second cell-specific reference signal corresponding to one or more ports of the base station. The first and second cell-specific reference signals may be correlated to verify the identity of the channel corresponding to the ports of the base station. ## Claims ### Claim 1 A channel identification system for a MIMO telecommunication system, comprising: an interface device communicatively couplable to a first port and a second port of a base station for receiving downlink signals on channels corresponding to the first port and the second port; and a processing device couplable to the interface device and having instructions that are executable by the processing device are configured to cause the processing device to: extract a first cell-specific reference signal from at least one of: (a) a first downlink signal of the downlink signals that does not include a first synchronization signal or (b) a second downlink signal of the downlink signals that includes a second synchronization signal and is associated with a secondary channel of the channels; generate a second cell-specific reference signal using signal information from at least one of the downlink signals; and determine a channel identification corresponding to at least one channel of the channels by correlating the first cell-specific reference signal and the second cell-specific reference signal. ### Claim 2 (depends on 1) The channel identification system of claim 1, wherein the processing device is further configured to: decode a broadcast channel for a signal of the downlink signals having an embedded synchronization signal. ### Claim 3 (depends on 1) The channel identification system of claim 1, wherein the processing device includes a memory device having instructions executable by the processing device for causing the processing device to extract the first cell-specific reference signal using a cell identifier, a cyclic prefix, a slot number, a symbol number, or a port number corresponding to a sample of the first downlink signal or the second downlink signal. ### Claim 4 (depends on 1) The channel identification system of claim 1, further including a memory device for storing digital samples of the downlink signals useable by the processing device to generate the second cell-specific reference signal. ### Claim 5 (depends on 1) The channel identification system of claim 1, wherein the processing device includes a memory device having instructions executable by the processing device for causing the processing device to generate the second cell-specific reference signal using a cell identifier, a cyclic prefix, a slot number, a symbol number, or a port number corresponding to a stored sample of at least one of the downlink signals. ### Claim 6 (depends on 1) The channel identification system of claim 1, wherein the processing device includes at least a field-programmable gate array communicatively coupled to the interface device and configured to synchronously capture samples of the downlink signals received from the base station. ### Claim 7 (depends on 1) The channel identification system of claim 1, wherein the processing device includes at least a measurement receiver positionable to receive samples of the downlink signals received from the base station and configured to identify a primary synchronization signal and a secondary synchronization signal embedded in at least one of the downlink signals. ### Claim 8 (depends on 1) The channel identification system of claim 1, wherein the processing device is disposed in a head-end unit of a telecommunication system. ### Claim 9 A multiple-input, multiple output telecommunication system, comprising: a head-end unit communicatively couplable to a first port and a second port of a base station for receiving downlink signals via channels corresponding to the first port and the second port, the head-end unit being configured to: extract a first cell-specific reference signal from one of (a) a first downlink signal of the downlink signals that does not include an embedded synchronization signal or (b) a second downlink signal of the downlink signals that includes the embedded synchronization signal and is associated with a secondary channel of the channels; generate a second cell-specific reference signal using signal information from at least one of the downlink signals; and determine a channel identification for each of the channels by correlating the first cell-specific reference signal and the second cell-specific reference signal; and one or more access points communicatively couplable to the head-end unit to receive the downlink signals and channel properties of the base station corresponding to the channel identification. ### Claim 10 (depends on 9) The multiple-input, multiple output telecommunication system of claim 9, wherein the head-end unit is further configured to: identify one or more synchronization signals embedded in at least one of the downlink signals; decode a broadcast channel for at least one of the downlink signals having the embedded synchronization signal to determine a total number of ports transmitting the downlink signals. ### Claim 11 (depends on 9) The multiple-input, multiple output telecommunication system of claim 9, wherein the head-end unit includes two ports positionable in the multiple-input, multiple output telecommunication system to receive the downlink signals from two base station ports. ### Claim 12 (depends on 9) The multiple-input, multiple output telecommunication system of claim 9, wherein the head-end unit includes four ports positionable in the multiple-input, multiple output telecommunication system to receive the downlink signals from four base station ports. ### Claim 13 (depends on 9) The multiple-input, multiple output telecommunication system of claim 9, wherein the head-end unit includes: a processing device; and a memory device having instructions executable by the processing device for causing the processing device to extract the first cell-specific reference signal using a cell identifier, a cyclic prefix, a slot number, a symbol number, or a port number corresponding to a sample of the first downlink signal or the second downlink signal. ### Claim 14 (depends on 9) The multiple-input, multiple output telecommunication system of claim 9, wherein the head-end unit includes: a processing device; and a memory device having instructions executable by the processing device for causing the processing device to generate the second cell-specific reference signal using the signal information, the signal information including one or more of a cell identifier, a cyclic prefix, a slot number, a symbol number, or a port number. ### Claim 15 (depends on 9) The multiple-input, multiple output telecommunication system of claim 9, wherein the head-end unit includes an interface device configured to receive the downlink signals and generate digital samples of the downlink signals. ### Claim 16 (depends on 15) The multiple-input, multiple output telecommunication system of claim 15, wherein the head-end unit includes: a processing device for which instructions executable by the processing device are configured to cause the processing device to synchronously capture the digital samples of the downlink signals; and a memory device for storing the digital samples of the downlink signals. ### Claim 17 A method, comprising: receiving a plurality of signals from ports of a base station, the ports corresponding to at least a primary channel and a secondary channel; extracting a first cell-specific reference signal from a signal of the plurality of signals, the signal including one of (a) a first signal having an embedded synchronization signal and received via the secondary channel or (b) a second signal that does not have the embedded synchronization signal; generating a second cell-specific reference signal using signal information from at least one of the plurality of signals; and determining a channel identification corresponding to a port of the base station by correlating the first cell-specific reference signal and the second cell-specific reference signal. ### Claim 18 (depends on 17) The method of claim 17, further including: synchronously capturing digital samples of the plurality of signals; and decoding a broadcast channel based on a location of the embedded synchronization signal. ### Claim 19 (depends on 17) The method of claim 17, further including: identifying one or more primary or secondary synchronization signals subsequent to down-sampling the plurality of signals; and re-identifying the one or more primary or secondary synchronization signals in a stored sample of the first signal or the second signal at a full sampling rate. ### Claim 20 (depends on 17) The method of claim 17, wherein generating the second cell-specific reference signal includes using a cell identifier, a cyclic prefix, a slot number, a symbol number, or a port number corresponding to a stored sample of the one of the plurality of signals.