Patent Application
20140269963
1. Field of the Disclosure
The present disclosure relates generally to a communication system, and more specifically to a communication system for adjusting signal bandwidths of information signals between a small signal bandwidth and a large signal bandwidth for transmission over a communication channel.
2. Related Art
Various communication standards, such as an Institute of Electrical and Electronics Engineers (IEEE) 802.16 family of wireless-networks standards, commonly referred to as Worldwide Interoperability for Microwave Access (WiMAX), a third generation (3G) mobile communication standard, a 3GPP Long Term Evolution (LTE) communication standard, and/or a fourth generation (4G) mobile communication standard to provide some examples, allocate their respective assigned frequency spectrum into smaller communication channels. For example, the 4G mobile communication standard is assigned to the 1.8-2.5 GHz and 2-8 GHz frequency spectrum. In this example, the 4G mobile communication standard allocates this frequency spectrum into smaller communication channels having selectable signal bandwidths between approximately 5 MHz and approximately 20 MHz. Various signal processing devices used by various communication devices of the 4G mobile communication standard typically operate at 20 MHz to process signals within these smaller communication channels. While these signal processing devices optimally process signals within the 20 MHz signal bandwidth, they are not optimally used for processing, signals within the 5-MHz signal bandwidth. The present disclosure provides for various processing devices that demultiplex several of these lower signal bandwidth channels to allow for the optimal use of their processing power.
The accompanying drawings illustrate the present disclosure and, together with the description, further serve to explain the principles of the disclosure and to enable one skilled in the pertinent art to make and use the disclosure.
The present disclosure will now be described with reference to the accompanying drawings. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the reference number.
The following Detailed Description refers to accompanying drawings to illustrate exemplary embodiments consistent with the disclosure. References in the Detailed Description to “one exemplary embodiment,” “an exemplary embodiment,” “an example exemplary embodiment,” etc., indicate that the exemplary embodiment described may include a particular feature, structure, or characteristic, but every exemplary embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same exemplary embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an exemplary embodiment, it is within the knowledge of those skilled in the relevant art(s) to affect such feature, structure, or characteristic in connection with other exemplary embodiments whether or not explicitly described.
The exemplary embodiments described herein are provided for illustrative purposes, and are not limiting. Other exemplary embodiments are possible, and modifications may be made to the exemplary embodiments within the spirit and scope of the disclosure. Therefore, the Detailed Description is not meant to limit the disclosure. Rather, the scope of the disclosure is defined only in accordance with the following claims and their equivalents.
Embodiments of the disclosure may be implemented in hardware, firmware, software, or any combination thereof. Embodiments of the disclosure may also be implemented as instructions stored on a machine-readable medium, which may be read and executed by processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing device). For example, a machine-readable medium may include a non-transitory machine-readable medium, such as read only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; flash memory devices; and others. As another example, the machine-readable medium may include transitory machine-readable medium, such as electrical, optical, acoustical, or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.). Further, firmware, software, routines, instructions may be described herein as performing certain actions. However, it should be appreciated that such descriptions are merely for convenience and that such actions in fact result from computing devices, processors, controllers, or other devices executing the firmware, software, routines, instructions, etc.
The following Detailed Description of the exemplary embodiments will so fully reveal the general nature of the disclosure that others can, by applying knowledge of those skilled in the relevant art(s), readily modify and/or adapt for various applications such exemplary embodiments, without undue experimentation, without departing from the spirit and scope of the disclosure. Therefore, such adaptations and modifications are intended to be within the meaning and plurality of equivalents of the exemplary embodiments based upon the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by those skilled it the relevant art(s) in light of the teachings herein.
For purposes of this discussion, the term “module” shall be understood to include at least one of software, firmware, and hardware (such as circuits, microchips, or devices, or any combination thereof), and any combination thereof. In addition, it will be understood that each module may include one, or more than one, component within an actual device, and each component that forms a part of the described module may function either cooperatively or independently of any other component forming a part of the module. Conversely, multiple modules described herein may represent a single component within an actual device. Further, components within a module may be in a single device or distributed among multiple devices in a wired or wireless manner.
The following Detailed Description describes a communication system having a transmitter that converts various information signals that collectively occupy a large signal bandwidth into various signals that individually occupy small signal bandwidths for transmission to a receiver. The receiver converts these various signals that individually occupy the small signal bandwidth to recovered information signals that collectively occupy the large signal bandwidth for processing.
Exemplary Communication Environment
The communication transmitter 102 provides transmitted communication signals 152.1 through 152.n by operating upon the one or more information signals 150 according to a known communication standard, such as, but not limited to, an Institute of Electrical and Electronics Engineers (IEEE) 802.16 family of wireless-networks standards, commonly referred to as Worldwide Interoperability for Microwave Access (WiMAX), a third generation (3G) mobile communication standard, a 3GPP Long Term Evolution (LTE) communication standard, a fourth generation (4G) mobile communication standard, and/or any other suitable communication standard that will be apparent to those skilled in the relevant art(s) without departing from the spirit and scope of the present disclosure. The one or more information signals 150 can include multiple electronic signals which are multiplexed in time, namely time-division multiplexed (TDM), and/or frequency, namely frequency-division multiplexed (FDM). As such, the transmitted communication signals 152.1 through 152.n can represent time division multiple access (TDMA) communication signals, orthogonal frequency division demultiplexed (OFDM) communication signals, code division multiple access (CDMA) communication signals, any other communication signals that can include orthogonal signaling dimensions, or any combination thereof. Additionally, the transmitted communication signals 152.1 through 152.n can be frequency division duplexed (FDD) and/or time-division duplexed (TDD) with other communication signals within the communication environment 100. In an exemplary embodiment, the communication transmitter 102 can be implemented within the MIMO communication environment. In this exemplary embodiment, the transmitted communication signals 152.1 through 152.n can represent the one or more information signals 150 as being transmitted from multiple transmission antennas. In another exemplary embodiment, the communication transmitter 102 can implement a carrier aggregation scheme. In this other exemplary embodiment, the transmitted communication signals 152.1 through 152.n can represent the one or more information signals 150 having different carrier frequencies. In a further exemplary embodiment, the communication transmitter 102 can implement the carrier aggregation scheme implemented within the MIMO communication environment.
The transmitted communication signals 152.1 through 152.n traverse through the communication link 104 to provide received communication signals 154.1 through 154.m. The transmitted communication signals 152.1 through 152.n can include a similar or a dissimilar number of communication signals as the received communication signals 154.1 through 154.m. In an exemplary embodiment, the communication link 104 can represent information carrying channels and/or control channels of a cellular communication network. For example, the communication link 104 can represent information carrying communication channels of the LTE communication standard, such as a Physical Downlink Shared Channel (PDSC), and/or a Physical Uplink Shared Channel (PUSCH) to provide some examples, control communication channels of the LTE communication standard, such as a Physical Uplink Control Channel (PUCCH), a Physical Downlink Control Channel (PDCCH), a Physical Control Format Indicator Channel (PCFICH), and/or a Physical Hybrid ARQ Indicator Channel (PHICH) to provide some examples, and/or any other suitable communication channel of the LTE communication standard, such as a Random Access Channel (RACH) and/or a sounding reference channel (SRS) to provide some examples.
The communication receiver 106 observes the received communication signals 154.1 through 154.m as they traverse through the communication link 104. In an exemplary embodiment, the communication receiver 106 can be implemented within the MIMO communication environment. In this exemplary embodiment, the received communication signals 154.1 through 154.m can represent the transmitted communication signals 152.1 through 152.n as being observed from multiple receiving antennas. For example, the received communication signals 154.1 through 154.m represent the multiple communication paths traversed by each of the transmitted communication signals 152.1 through 152.n through the communication link 104. For example, the received communication signal 154.1 represents the transmitted communication signals 152.1 through 152.n as they traverse through a first communication path of the communication link 104. Likewise, the received communication signal 154.m represents the transmitted communication signals 152.1 through 152.n as they traverse through an mth communication path of the communication link 104. In another exemplary embodiment, the communication receiver 106 can implement the carrier aggregation scheme. In this other exemplary embodiment, the received communication signals 154.1 through 154.m can represent the transmitted communication signals 152.1 through 152.n having different carrier frequencies as they traverse through the communication link 104. In a further exemplary embodiment, the communication receiver 106 can implement the carrier aggregation scheme implemented within the MIMO communication environment. It should be noted that the communication transmitter 102 and the communication receiver 106 can both be implemented within a base station or access point of a cellular communication network. In this configuration, that the communication transmitter 102 can provide the transmitted communication signals 152.1 through 152.n representing uplink communication signals to one or more mobile stations via an uplink communication channel and the communication receiver 106 can receive the received communication signals 154.1 through 154.m representing downlink communication signals from the one or more mobile stations via a downlink communication channel.
The communication receiver 106 can recover the one or more information signals 150 from the received communication signals 154.1 through 154.m to provide one or more recovered information signals 156 for one or more receiver user devices by operating upon the received communication signals 154.1 through 154.m according to the known communication standard. The receiver user devices can include, but are not limited to, personal computers, data terminal equipment, telephony devices, broadband media players, personal digital assistants, software applications, or any other medium capable of transmitting or receiving data.
In some situations, the communication transmitter 102 and the communication receiver 106 can include multiple transmitting antennas and multiple receiving antennas, respectively, to form the MIMO communication environment. In other situations, the communication transmitter 102 and the communication receiver 106 can include multiple transmitting antennas and a single receiving antenna, respectively, to form a multiple-input and single-output (MISO) communication environment. In yet other situations, the communication transmitter 102 and the communication receiver 106 can include a single transmitting antenna and multiple receiving antennas, respectively, to form a single-input and multiple-output (SIMO) communication environment.
Often times, a governing authority, such as the Federal Communication Commission (FCC) or any other like governing authority, uniquely allocates frequency spectrum for use by the communication environment 100. This frequency spectrum can be further allocated into smaller portions of frequency spectrum, often referred to as communication channels, according to the known communication standard. In some situations, the communication channels can be characterized as having a selectable signal bandwidth. In these situations, it is desirable to have the communication transmitter 102 be capable of operating upon signals having large signal bandwidths, such as approximately 20 MHz to provide an example, and demultiplexing or separating communication signals having the large signal bandwidths to provide signals that have small signal bandwidths, such as approximately 10 MHz to provide an example, for transmission over communication channels that support these smaller signal bandwidths. It is also desirable to have the communication receiver 106 be capable of operating upon signals having the large signal bandwidths and multiplexing or combining communication signals having the small signal bandwidths to provide signals that have the large signal bandwidth for processing. The demultiplexing or separating by the communication transmitter 102 and/or the multiplexing or combining by the communication receiver 106 allows the communication transmitter 102 and/or the communication receiver 106 to advantageously utilize their large signal bandwidth processing capabilities when operating upon signals having smaller signal bandwidths.
Exemplary Communication Transmitter
The processing module 202 operates upon the one or more information signals 150 in accordance with a known communication standard, such as, but not limited to, the WiMAX communication standard, the 3G mobile communication standard, the LTE communication standard, the 4G mobile communication standard, and/or any other suitable communication standard that will be apparent to those skilled in the relevant art(s) without departing from the spirit and scope of the present disclosure, to provide a processed information signal 250. Additionally, the processing module 202 can provide various electronic signals that are specified in accordance with the known communication standard as the processed information signal 250. These electronic signals can be multiplexed in time, namely time-division multiplexed (TDM), and/or frequency, namely frequency-division multiplexed (FDM), with the one or more information signals 150.
The front end module 204 demultiplexes or separates the processed information signal 250 to provide transmitted communication signals 254.1 through 254.n. Specifically, the front end module 204 demultiplexes or separates the processed information signal 250 having a large signal bandwidth to provide transmitted communication signals 254.1 through 254.n having small signal bandwidths. The front end module 204 includes an interface module 208 and radio frequency integrated circuits (RFICs) 210.1 through 210.d. The interface module 208 demultiplexes or separates the processed information signal 250, which occupies a large signal bandwidth, such as approximately 20 MHz using a large sampling rate of approximately 30.72 MHz to provide an example, in the analog, signal domain, the digital signal domain, or any combination thereof to provide demultiplexed information signals 252.1 through 252.d. The demultiplexed information signals 252.1 through 252.d individually have a small signal bandwidth, such as approximately 20/d MHz to provide an example. In an exemplary embodiment, the interface module 208 demultiplexes or separates the processed information signal 250 into the demultiplexed information signals 252.1 through 252.2 that individually occupy a signal bandwidth of approximately 10 MHz.
The RFICs 210.1 through 210.d operate on their corresponding demultiplexed information signals 252.1 through 252.d to provide the transmitted communication signals 254.1 through 254.n. The RFICs 210.1 through 210.d can frequency translate or upconvert their corresponding demultiplexed information signals 252.1 through 252.d to a radio frequency (RF) or any other suitable frequency using a suitable upconversion process that will be apparent to those skilled in the relevant art(s). The RFICs 210.1 through 210.d can additionally separate the their corresponding demultiplexed information signals 252.1 through 252.d into corresponding transmitted communication signals 254.1 through 254.n for transmission in the MIMO communication environment and/or a carrier aggregation scheme such as the communication environment 100 to provide an example. The RFICs 210.1 through 210.d can, optionally, convert their corresponding demultiplexed information signals 252.1 through 252.d from a representation in the digital signal domain to a representation in the analog signal domain. The RFICs 210.1 through 210.d can, optionally, modulate and/or encode their corresponding demultiplexed information signals 252.1 through 252.d in accordance with the known communication standard.
The transmitting antennas 206.1 through 206.n provide the transmitted communication signals 152.1 through 152.n to the communication channel. The transmitting antennas 206.1 through 206.n convert the transmitted communication signals 254.1 through 254.n from electromagnetic currents to electromagnetic waves to provide the transmitted communication signals 152.1 through 152.n. Typically, one or more of the transmitting antennas 206.1 through 206.n are coupled to each of the RFICs 210.1 through 210.d. For example, as shown in
First Exemplary Front End Module that can be Implemented as Part of the Exemplary Communication Transmitter
As shown in
The digital interface module 302 demultiplexes or separates the processed information signal 250 in the digital signal domain to provide the demultiplexed communication signals 354.1 and 354.2 having small signal bandwidths. The digital interface module 302 includes a digital multiplier 306 and half-band decimation filters 308.1 and 308.2. The digital interface module 302 can represent an exemplary embodiment of the interface module 208.
The digital multiplier 306 frequency translates the processed information signal 250 using a digital local oscillator signal 350 to provide a translated information signal 352. For example, as shown in
The half-band decimation filters 308.1 and 308.2 digitally down sample and half band filter the processed information signal 250 to provide the demultiplexed communication signal 354.1 and the translated information signal 352 to provide the demultiplexed communication signal 354.2, respectively. The downsampling of the processed information signal 250 and the translated information signal 352, by the half-band decimation filters 308.1 and 308.2 respectively, effectively down samples and half band filters the processed information signal 250 and the translated information signal 352 from the large signal bandwidths to the small signal bandwidths. For example, as shown in
The RFICs 304.1 and 304.2 operate on their corresponding demultiplexed communication signals 354.1 and 354.2 to provide the transmitted communication signals 254.1 through 254.4 in a substantially similar manner as the RFICs 210.1 through 210.d.
Second Exemplary Front End Module that can be Implemented as Part of the Exemplary Communication Transmitter
The analog interface module 402 demultiplexes or separates the processed information signal 250 in the analog signal domain to provide the demultiplexed communication signals 450.1 and 450.2 having small signal bandwidths. The analog interface module 402 includes a demultiplexer module 414, separation modules 406.1 through 406.4, packing and multiplexer modules 408.1 through 408.4, and multiplexer modules 410.1 through 410.2. The analog interface module 402 can represent an exemplary embodiment of the interface module 208.
As discussed above, the processed information signal 250 can include one or more information signals that collectively occupy a large signal bandwidth, such as approximately 20 MHz to provide an example. In some situations, each of these one or more information signals can represent quadrature phase information signals that include in-phase (I) components and quadrature phase (Q) components. In an exemplary embodiment, the processed information signal 250 includes two information signals that collectively occupy the large signal bandwidth. In this exemplary embodiment, a first information signal from among the two information signals includes a first I component and a first Q component and a second information signal from among the two information signals includes a second I component and a second Q component. In, this exemplary embodiment, the first information signal can be from a first cell in a cellular network and the second information signal can be from a second, neighboring cell in the cellular network. As such, the first information signal and/or the second information signal can include multiple electronic signals which are multiplexed in time, namely time-division multiplexed (TDM), and/or frequency, namely frequency-division multiplexed (FDM).
The demultiplexer module 414 demultiplexes or separates the processed information signal 250 into I components 452 and Q components 454. From the exemplary embodiment above, the demultiplexer module 414 demultiplexes or separates the first information signal into a first I component 452.1 and a first Q component 454.1 and the second information signal into a second I component 452.2 and a second Q component 454.2.
The separation modules 406.1 through 406.4 further demultiplex or separate their corresponding I components 452 and the Q components 454 into negative components 456 or positive components 458. Each of the separation modules 406.1 through 406.4 is implemented in a substantially similar manner; therefore, only the separation module 406.1 is to be discussed in further detail. The separation module 406.1 demultiplexes or separates the first I component 452.1 into a first negative component 456.1 which represents components of the first I component 452.1 that are less than approximately zero and a second positive component 458.1 which represents components of the first I component 452.1 that are greater than approximately zero. The separation module 406.1 includes a Hilbert filter module 412 and combination modules 414.1 and 414.2.
The Hilbert filter module 412 performs a Hilbert transform upon the first I component 452.1 to shift a phase of all frequency components of the first I component 452.1 by approximately −π/2 radians to provide a transformed component 460. The Hilbert transform, H(f), can be denoted as:
j,f<0,
0,f=0, and
−j,f>0, (1)
where j represents a basic imaginary unit √{square root over (−1)} and f represents a frequency component of the first I component 452.1. From the exemplary embodiment above, the first information signal and the second information signal within the processed information signal 250 are substantially equally spread between two sides of the frequency origin allowing the use of the Hilbert transform to clean adjacent, unwanted sides from among the first I component 452.1. In an exemplary embodiment, the Hilbert filter module 412 is implemented with 256 coefficients to ensure the transformed component 460 is sufficiently flat and has sufficient rejection. In some situations, the processed information signal 250 can include one or more guard bands of approximately 15 kHz each to ensure that the Hilbert filter module 412 meets flatness and rejection requirement in accordance with the known communication standard. In these situations, the number of coefficients of the Hilbert filter module 412 is related to the number of guard bands within the processed information signal 250. A fewer number of coefficients requires more guard bands to meet the rejection requirement whereas more coefficients requires less guard bands to meet the rejection requirement. In an exemplary embodiment, the Hilbert filter module 412 is implemented with 126 coefficients and the processed information signal 250 includes 3 guard bands of 15 kHz each to meet the rejection requirement. In this exemplary embodiment, the Hilbert filter module 412 can be implemented in poly-phase with 8 phases of 16 adaptive filter tapes each.
The combination module 414.1 subtracts the transformed component 460 from the first I component 452.1 to provide the first negative component 456.1. Similarly, the combination module 414.2 combines the transformed component 460 and the first I component 452.1 to provide the first positive component 458.1.
The packing and multiplexer modules 408.1 through 408.4 multiplex or combine various similar negative or positive components from among the negative components 456 or positive components 458 in the analog signal domain to provide multiplexed negative components 462 or multiplexed positive components 464. For example, the packing and multiplexer modules 408.1 and 408.3 multiplex or combine the first negative component 456.1 and the second negative component 456.2 to provide a first multiplexed negative component 462.1 and the third negative component 456.3 and the fourth negative component 456.4 to provide a second multiplexed negative component 462.2, respectively. As another example, the packing and multiplexer modules 408.2 and 408.4 multiplex or combine the first positive component 458.1 and the second positive component 458.2 to provide a first multiplexed positive component 464.1 and the third positive component 458.3 and the fourth positive component 458.4 to provide a second multiplexed positive component 464.2, respectively.
From the exemplary embodiment above, the packing and multiplexer module 408.1 multiplexes or combines the first negative component 456.1 representing I components of the first information signal that are less than approximately zero and the second negative component 456.2 representing Q components of the first information signal that are less than approximately zero to provide the first multiplexed negative component 462.1. In this exemplary embodiment, the packing and multiplexer module 408.2 multiplexes of combines the first positive component 458.1 representing I components of the first information signal that are greater than approximately zero and the second positive component 458.2 representing Q components of the first information signal that are greater than approximately zero to provide a first multiplexed positive component 464.1. In this exemplary embodiment, the packing and multiplexer module 408.3 multiplexes or combines the third negative component 456.3 representing I components of the second information signal that are less than approximately zero and the fourth negative component 456.4 representing Q components of the first information signal that are less than approximately zero to provide a second multiplexed negative component 462.2. In this exemplary embodiment, the packing and multiplexer module 408.4 multiplexes or combines the third positive component 458.3 representing I components of the second information signal that are greater than approximately zero and the second positive component 458.4 representing Q components of the second information signal that are greater than approximately zero to provide a second multiplexed positive component 464.2.
The multiplexer modules 410.1 through 410.2 multiplex or combine the first and second multiplexed negative components 462.1 and 462.2 to provide the demultiplexed communication signal 450.1 and the first and the second multiplexed positive components 464.1 and 464.2 to provide the demultiplexed communication signal 450.2, respectively. From the exemplary embodiment above, the demultiplexed communication signal 450.1 includes I and Q components of the first and second information signals that are less than approximately zero that collectively occupy the small signal bandwidth, such as approximately 10 MHz to provide an example. The demultiplexed communication signal 450.2 includes I and Q components of the first and second information signals that are greater than approximately zero that collectively occupy the small signal bandwidth.
The RFICs 404.1 and 404.2 operate on their corresponding demultiplexed communication signals 450.1 and 450.2 to provide the transmitted communication signals 254.1 through 254.2 in a substantially similar manner as the RFICs 210.1 through 210.d; therefore, only differences between the RFICs 404.1 and 404.2 and the RFICs 210.1 through 210.d are to be discussed in further detail below. The RFICs 404.1 and 404.2 can frequency translate or upconvert their corresponding demultiplexed communication signals 450.1 and 450.2 to a radio frequency (RF) or any other suitable frequency using a suitable upconversion process that will be apparent to those skilled in the relevant art(s) using a corresponding local oscillator signal 466.1 and 466.2. In an exemplary embodiment, the local oscillator signal 466.1 is offset approximately −2.25 MHz from a RF carrier frequency while the local oscillator signal 466.2 is offset approximately 2.25 MHz from the RF carrier frequency. In another exemplary embodiment, the local oscillator signal 466.1 is offset approximately −2.295 MHz from a RF carrier frequency while the local oscillator signal 466.2 is offset approximately 2.295 MHz from the RF carrier frequency. The difference in offset of the local oscillator signal 466.1 and the local oscillator signal 466.2 from the RF carrier frequency in these two exemplary embodiments is related to the number of guard bands within the processed information signal 250 which is 3 guard bands of 15 kHz each.
Exemplary Communication Receiver
The receiving antennas 502.1 through 502.m receive the received communication signals 154.1 through 154.m as they traverse through the communication channel. The receiving antennas 502.1 through 502.m convert the received communication signals 154.1 through 154.m from electromagnetic currents to electromagnetic waves to provide the received communication signals 550.1 through 550.4.
The front end module 504 multiplexes or combines the received communication signals 550.1 through 550.4 to provide a multiplexed communication signal 554. Specifically, the front end module 504 multiplexes or combines the received communication signals 550.1 through 550.4 having small signal bandwidths to provide the multiplexed communication signal 554 having a large signal bandwidth. The front end module 504 includes radio frequency integrated circuits (RFICs) 508.1 through 508.e and an interface module 510.
The RFICs 508.1 through 508.e operate on their corresponding received communication signals 550.1 through 550.4 to provide recovered communication signals 552.1 through 552.e. The RFICs 508.1 through 508.e can frequency translate or downconvert their corresponding received communication signals 550.1 through 550.4 to a baseband frequency or any other suitable frequency using a suitable upconversion process that will be apparent to those skilled in the relevant art(s). The RFICs 508.1 through 508.e can, optionally, convert their corresponding received communication signals 550.1 through 550.4 from a representation in the analog signal domain to a representation in the digital signal domain. The RFICs 508.1 through 508.e can, optionally, demodulate and/or decode their corresponding received communication signals 550.1 through 550.4 in accordance with the known communication standard.
Typically, each of the RFICs 508.1 through 508.e is coupled to one or more of the receiving antennas 502.1 through 502.m. For example, as shown in
The interface module 510 multiplexes or combines the recovered communication signals 552.1 through 552.e which individually occupy small signal bandwidths, such as approximately 20/e MHz to provide an example, in the analog signal domain, the digital signal domain, or any combination thereof to provide the multiplexed communication signal 554. The multiplexed communication signal 554 collectively has a large signal bandwidth, such as approximately 20 MHz to provide an example. In an exemplary embodiment, the interface module 510 multiplexes or combines the recovered communication signals 552.1 through 552.e into the multiplexed communication signal 554 that collectively occupies a signal bandwidth of approximately 20 MHz using a sample rate of approximately 30.72 MHz.
The processing module 506 operates upon the multiplexed communication signal 554 in accordance with the known communication standard to provide the one or more recovered information signals 156.
First Exemplary Front End Module that can be Implemented as Part of the Exemplary Communication Receiver
The RFICs 602.1 and 602.2 operate on their received communication signals 550.1 through 550.4 to provide recovered communication signals 650.1 and 650.2 in a substantially similar manner as the RFICs 508.1 through 508.e. The recovered communication signals 650.1 and 650.2 include one or more information signals that individually occupy small signal bandwidths, such as approximately 10 MHz to provide an example. The one or more information signals can be allocated to occupy different and/or similar portions of the large signal bandwidth. For example, as shown in
The digital interface module 604 multiplexes or combines the recovered communication signals 650.1 and 650.2 in the digital signal domain to provide the multiplexed communication signal 554 having the large signal bandwidth. The digital interface module 604 includes half-band interpolation filters 606.1 and 606.2, a digital multiplier 608, and a combination module 610. The digital interface module 604 can represent an exemplary embodiment of the interface module 510.
The half-band interpolation filters 606.1 and 606.2 digitally upsample and half band filter the recovered communication signals 650.1 and 650.2 provide up-sampled communication signals 652.1 and 652.2. The upsampling of the recovered communication signals 650.1 and 650.2 by the half-band interpolation filters 606.1 and 606.2 effectively upsamples and half band filters the recovered communication signals 650.1 and 650.2 from the small signal bandwidths to the large signal bandwidths. For example, as shown in
The digital multiplier 608 frequency translates the up-sampled communication signal 652.1 using a digital local oscillator signal 654 to provide a translated communication signal 656. For example, as shown in
The combination module 610 combines the up-sampled communication signal 652.1 and the translated communication signal 656 to provide the multiplexed communication signal 554. For example, as shown in
Second Exemplary Front End Module that can be Implemented as Part of the Exemplary Communication Receiver
The RFICs 702.1 and 702.2 operate on their received communication signals 550.1 through 550.4 to provide recovered communication signals 750.1 and 750.2 in a substantially similar manner as the RFICs 508.1 through 508.e; therefore, only differences between the RFICs 508.1 through 508.e and the RFICs 702.1 and 702.d are to be discussed in farther detail below. The RFICs 702.1 and 702.2 can frequency translate or downconvert their corresponding from received communication, signals 550.1 through 550.4 from a radio frequency (RF) to baseband or any other suitable frequency using a suitable downconversion process that will be apparent to those skilled in the relevant art(s) using a corresponding local oscillator signal 752.1 and 752.2. In an exemplary embodiment, the local oscillator signal 752.1 is offset approximately −2.25 MHz from a RF carrier frequency while the local oscillator signal 752.2 is offset approximately 2.25 MHz from the RF carrier frequency. In another exemplary embodiment, the local oscillator signal 752.1 is offset approximately −2.295 MHz from a RF carrier frequency while the local oscillator signal 752.2 is offset approximately 2.295 MHz from the RF carrier frequency. The difference in offset of the local oscillator signal 752.1 and the local oscillator signal 752.2 from the RF carrier frequency in these two exemplary embodiments is related to the number of guard bands within the received communication signals 550.1 through 550.4 which are 3 guard bands of 15 kHz each.
The analog interface module 702 multiplexes or combines the recovered communication signals 750.1 and 750.2 that individually occupy small signal bandwidths in the analog signal domain to provide the multiplexed communication signal 554 that occupies the large signal bandwidth. The analog interface module 704 includes demultiplexer modules 706.1 and 706.2, combination modules 708.1 through 708.4, and a multiplexer module 710. The analog interface module 704 can represent an exemplary embodiment of the interface module 410.
As discussed above, the received communication signals 550.1 through 550.4 can include one or more information signals that individually occupy small signal bandwidths, such as approximately 10 MHz to provide an example. In some situations, each of these one or more information signals can represent quadrature phase information signals that include in-phase (I) components and quadrature phase (Q) components. In an exemplary embodiment, the received communication signals 550.1 through 550.4 include two information signals that individually occupy the small signal bandwidth. In this exemplary embodiment, a first information signal from among the two information signals includes a first I component and a first Q component and a second information signal from among the two information signals includes a second I component and a second Q component. In this exemplary embodiment, the first information signal can be from a first cell in a cellular network and the second information signal can be from a second, neighboring cell in the cellular network. As such, the first information signal and/or the second information signal can include multiple electronic signals which are multiplexed in time, namely time-division multiplexed (TDM), and/or frequency, namely frequency-division multiplexed (FDM).
The demultiplexer modules 706.1 and 706.2 demultiplexes their corresponding recovered communication signals 750.1 and 750.2 into negative components 754.1 through 754.4 and positive components 756.1 through 756.4, respectively. The negative components 754.1 through 754.4 represent components of the recovered communication signals 750.1 that are less than approximately zero and the positive components 756.1 through 756.4 represent components of the recovered communication signals 750.2 that are greater than approximately zero. The negative components 754.1 through 754.4 and the positive components 756.1 through 756.4 individually occupy the small signal bandwidth, such as approximately 10 MHz to provide an example.
The combination modules 708.1 through 708.4 multiplex or combine various similar negative and positive components from among the negative components 754 or positive components 756 in the analog signal domain to provide multiplexed signal components 758.1 through 758.4. From the exemplary embodiment above, the combination module 708.1 multiplexes or combines the negative component 754.1 and the positive component 756.1 to provide the multiplexed signal component 758.1 which represents the first I component of the first information signal from among the two information signals. Also from the exemplary embodiment above, the combination module 708.2 multiplexes or combines the negative component 754.2 and the positive component 756.2 to provide the multiplexed signal component 758.2 which represents the first Q component of the first information signal from among the two information signals. Further from the exemplary embodiment above, the combination module 708.3 multiplexes or combines the negative component 754.3 and the positive component 756.3 to provide the multiplexed signal component 758.3 which represents the second I component of the second information signal from among the two information signals. Yet further from the exemplary embodiment above, the combination module 708.4 multiplexes or combines the negative component 754.4 and the positive component 756.4 to provide the multiplexed signal component 758.4 which represents the second Q component of the second information signal from among the two information signals.
The multiplexer module 710 multiplexes or combines the multiplexed signal components 758.1 through 758.4 to provide the multiplexed communication signal 554. From the exemplary embodiment above, the multiplexed signal components 758.1 through 758.4 includes I and Q components of the first and second information signals that are less than approximately zero that collectively occupy the small signal bandwidth, such as approximately 10 MHz to provide an example. The multiplexed communication signal 554 includes I and Q components of the first and second information signals that collectively occupies the large signal bandwidth.
It is to be appreciated that the Detailed Description section, and not the Abstract section, is intended to be used to interpret the claims. The Abstract section can set forth one or more, but not all exemplary embodiments, of the disclosure, and thus, are not intended to limit the disclosure and the appended claims in any way.
The disclosure has been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.
It will be apparent to those skilled in the relevant art(s) that various changes in form and detail can be made therein without departing from the spirit and scope of the disclosure. Thus the disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
