330.

FIGS. 4A-D illustrate various configurations for a digital filter that may be implemented in conjunction with embodiments provided herein. A digital filter is a system that performs mathematical operations on a sampled, discrete-time signal to reduce or enhance certain aspects of that signal. A digital filter system usually includes an analog-to-digital converter (ADC) to sample the input signal, followed by a microprocessor and some peripheral components such as memory to store data and filter coefficients. Program Instructions running on the microprocessor implement the digital filter by performing necessary mathematical operations on the numbers received from the ADC. In some high performance applications, a field programmable gate array (FPGA) or application specific integrated circuit (ASIC) is used instead of a general purpose microprocessor, or a specialized digital signal processor (DSP) with specific paralleled architecture for expediting operations such as filtering.

Digital filters may, in some embodiments, be provided at both the wireless device and the access node. The digital filter may, for example, be or include a finite impulse response (FIR) filter operating on input signals to take one sequence of numbers and produce another as the filtered output signal. Various types of filters may be implemented, including for example a lowpass filter 402 as shown in FIG. 4A, a highpass filter 404 as shown in FIG. 4B, a bandpass filter 406 as shown in FIG. 4C, and a band reject filter 408 as shown in FIG. 4D. These filters may be used separately or in combination depending on the selected spectrum blocks.

The filters illustrated in FIGS. 4A-4D illustrate frequency along the x-axis and amplitude along the y-axis. The lowpass filter 402 of FIG. 4A shows a range of passed signals at 412 and a higher ranged of blocked signals at 414. Conversely, the highpass filter 404 of FIG. 4B illustrates a blocked range of signals at 422 and a higher passed range of signals at 424. FIG. 4C illustrates a bandpass filter 406 that functions as a combination of a lowpass and highpass filter and allows frequencies above a certain point and below another. Accordingly, blocked frequencies are shown at 432 and 436 and passed frequencies are shown at 434.

FIG. 4D illustrates a band reject filter 408. In embodiments set forth herein, multiple band reject filters 408 may be utilized. The band reject filter 408 may reject or attenuate a middle spectrum block at 444 and pass lower frequencies 442 and higher frequencies at 446.

Thus, embodiments set forth herein may use combinations of digital filters based on selected spectrum blocks. As set forth herein, the selected spectrum blocks may simply be the spectrum blocks owned by a particular communications entity such as, for example, a mobile carrier. Spectrum blocks excluded may be those owned by other communications entities, those reserved for emergency signaling, or spectrum blocks unavailable for any other reason.

FIG. 5 is a block diagram 500 depicting an exemplary access node 510 for use with embodiments set forth herein. Access node 510 may comprise, for example, a macro-cell access node, such as the access nodes described with reference to FIG. 1. Access node 510 may be connected to a network 501 using communication link 506. Access node 510 is illustrated as comprising a processor 511, memory 512, transceiver(s) 513, antenna(s) 514, and scheduler 515. The access node 510 is also illustrated as including a digital filter 520. Processor 511 executes instructions stored on memory 512, while transceiver(s) 513 and antenna(s) 514 enable wireless communication with other network nodes, such as wireless devices and other nodes.

For example, access node 510 may be configured to select particular spectrum blocks based on ownership of the spectrum blocks and/or required exclusion of particular spectrum blocks, define a carrier encompassing the spectrum blocks, and a apply the digital filter 520 to create a profile for the carrier. Further, the access node 510 may be configured to match the profile of the carrier with UE capabilities and communicate information identifying matching spectrum blocks to the UE.

Scheduler 515 may be provided for scheduling resources based on the presence of the wireless devices. These features may be enabled by access node 510 comprising co-located cells, or antenna/transceiver combinations that are mounted on the same structure. Network 501 may be similar to network 101 discussed above. Wireless communication links 516 and 518 may provide communication with the access node 510 over one or more RATs. In some embodiments, the wireless devices may operate in NB-IoT mode or Cat M1 mode enabling the wireless devices to communicate with access node 510 over a relatively narrow bandwidth.

Further, instructions stored on memory 512 can include instructions for defining a carrier profile and matching the carrier profile with wireless device capabilities as further set forth herein. Methods for defining the carrier utilizing a digital filter are further explained below with reference to FIGS. 6 and 7. The instructions may facilitate selection of spectrum blocks, application of digital filter to develop a carrier having a profile, comparing the profile with wireless device capabilities as will be further described herein, and communicating information identifying the matching spectrum blocks to the wireless device.

The disclosed methods for performing definition of a carrier are further described with references to FIGS. 6 and 7 below. FIG. 6 illustrates an exemplary method 600 for defining a carrier using a digital filter in accordance with disclosed embodiments. Method 600 may be performed by any suitable processor discussed herein, for example, a processor included in the access node 510. Although FIG. 6 depicts steps performed in a particular order for purposes of illustration and discussion, the operations discussed herein are not limited to any particular order or arrangement. One skilled in the art, using the disclosures provided herein, will appreciate that various steps of the methods can be omitted, rearranged, combined, and/or adapted in various ways.

Method 600 starts in step 610 when the access node 510 or similar component selects a range of spectrum blocks. In embodiment set forth herein, this selection could be made within a particular frequency band. For example, the access node 510 or similar component selects a frequency band and within that frequency band, selects a lowest spectrum block usable in the network and a highest spectrum block in the frequency band usable by the network. The access node may define this range of spectrum blocks as a wide carrier and then apply a digital filter knocking out unusable blocks to the generate a profile of the carrier in step