HK1182544B - Communication pathway supporting an advanced split microwave backhaul architecture - Google Patents

Abstract

The present invention is directed to a communication pathway supporting an advanced split microwave backhaul architecture. The advanced architecture includes an indoor communication unit including a digital modem assembly configured to modulate and demodulate digital data, and also includes a digital interface module configured to transmit and/or receive the digital data, over a digital communication pathway, between the indoor communication unit and an external outdoor communication unit. The advanced architecture further includes an outdoor communication unit having a digital interface module configured to transmit and/or receive the digital data, over the digital communication pathway, between the outdoor communication unit and an external indoor communication unit, and also includes a digital to analog converter configured to convert the digital data to analog data and an analog to digital converter configured to convert the analog data to the digital data, and further includes an RF module configured to convert the analog data between a baseband and a radio frequency.

Description

Communication path supporting advanced split microwave backhaul architecture

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. provisional patent application No. 61/565,469 filed on 30/11/2011 and U.S. patent application No. 13/535,196 filed on 27/6/2012, the entire contents of which are incorporated herein by reference.

Technical Field

The present invention relates generally to microwave backhaul architectures and, more particularly, to an advanced split microwave backhaul architecture that supports digital communication paths.

Background

Conventional microwave backhaul architectures are typically implemented as either split outdoor unit (split ODU) or all outdoor unit (all ODU) architectures. Conventional split ODU structures typically include both indoor units (IDUs) and outdoor units (ODUs), where the IDUs and ODUs are connected by a coaxial interconnect. The IDU in a conventional split ODU architecture typically includes a modem, a digital-to-analog converter, and a baseband-to-intermediate frequency converter. Under normal operation, these conventional split ODU architectures typically involve the transmission of analog signals at intermediate frequencies over the coaxial interconnect between the IDU and the ODU. There are many limitations to the use of coaxial interconnects to transport analog signals between IDUs and ODUs. For example, coaxial interconnects may be quite expensive to implement, may have limited bandwidth, and may suffer from signal loss under certain conditions.

Mobile backhaul providers are experiencing increasing demands for increased capacity and a shift from voice services to data services. These factors are driving mobile backhaul networks to step toward high capacity IP/ethernet connections. In addition, the transition to 4G and LTE networks is also driving the demand for higher capacity and is moving more data packet traffic onto mobile backhaul networks. As a result, the limitations of conventional split ODU architectures make it increasingly difficult to meet these increased user requirements.

In some cases, the all ODU structure has been used as a replacement for these conventional split ODU structures. Conventional all ODU structures include only ODUs and therefore do not include IDUs. Thus, the ODU includes a modem, a digital-to-analog converter, and a baseband-to-radio frequency converter. The implementation of all these functional components in ODUs typically allows the implementation of digital connections within these conventional all ODU architectures. This is in contrast to the analog connections utilized in conventional split ODU architectures. However, the conventional all ODU structure still has limitations. For example, including this functionality entirely in the ODU increases installation and maintenance costs and may result in inefficient power consumption.

Therefore, neither the conventional split ODU structure nor the all ODU structure can effectively satisfy the increasing demand for capacity. Accordingly, there is a need for an advanced split microwave backhaul architecture that overcomes the shortcomings of the conventional architecture.

Disclosure of Invention

To this end, the present invention provides an indoor communication unit in a split backhaul structure, comprising: a digital modem component configured to modulate and demodulate digital data; a digital interface module coupled to a digital modem assembly configured to communicate digital data between the indoor communication unit and an external outdoor communication unit over a digital communication path.

Preferably, the indoor communication unit further comprises multiplexer means.

Preferably, the digital communication path is configured to perform as a dual channel path.

Preferably, the digital communication path is a wireless channel.

Preferably, the digital communication path is configured to support a bandwidth in the range of about 2.5Gbp to about 10 Gbp.

Preferably, the digital communication path is a time division and frequency division path.

Preferably, the indoor communication unit further comprises one or more additional digital communication paths, each additional digital communication path being configured to communicate digital data between the indoor communication unit and the outdoor communication unit and one or more additional outdoor communication units.

Preferably, the digital modem assembly, the digital interface module and the multiplexer are all bi-directional.

Preferably, the digital communication path is configured to perform as an optical feedback loop.

The present invention also provides an outdoor communication unit in a split backhaul configuration, comprising: a digital interface module configured to communicate digital data between the outdoor communication unit and an external indoor communication unit over a digital communication path; a digital-to-analog converter coupled to the digital interface module; an analog-to-digital converter; and an RF module configured to convert analog data from baseband to radio frequency.

Preferably, the outdoor communication unit further comprises multiplexer means.

Preferably, the digital communication path is configured to perform as a dual channel path.

Preferably, the digital communication path comprises one or more copper wires.

Preferably, the digital communication path is a time division and frequency division path.

Preferably, the outdoor communication unit further comprises one or more additional digital communication paths, each additional digital communication path configured to communicate digital data between the outdoor communication unit and the indoor communication unit and one or more additional indoor communication units.

Preferably, the digital interface module, the digital-to-analog converter, the analog-to-digital converter and the RF module are all bi-directional.

Preferably, the digital communication path is configured to perform as an optical feedback loop.

The invention also provides a method for communicating data through a split microwave backhaul system, comprising: receiving, at a first data interface module located at the outdoor communication unit, modulated digital data from a second digital interface module located at the indoor communication unit over a digital communication path; at the outdoor communication unit, canceling noise within the modulated digital data, wherein the noise is associated with at least one of the indoor communication unit and the digital communication path; converting the modulated digital data into analog data at the outdoor communication unit; and at the outdoor communication unit, converting the analog data from baseband to radio frequency over a wireless link.

Preferably, the method further comprises: receiving, at an outdoor communication unit, analog data from an antenna; converting the analog data from radio frequency down to baseband in an outdoor communication unit; converting the analog data to digital data at the outdoor communication unit; multiplexing the digital data; and demodulating the digital data at the indoor communication unit.

Preferably, the modulated digital data is modulated at the indoor communication unit and the up-converted analog data is transmitted over a wireless link from an antenna located at the outdoor communication unit.

Drawings

Embodiments of the invention will be described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. Additionally, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears.

Fig. 1 shows a block diagram of a split microwave backhaul system according to an example embodiment of the present invention.

Fig. 2 shows a block diagram of a split microwave backhaul system with an indoor communication unit (IDU), an outdoor communication unit (ODU) and associated digital communication paths, according to an example embodiment of the present invention.

Fig. 3.1 shows a block diagram of a split microwave backhaul system with an indoor communication unit (IDU), a plurality of outdoor communication units (ODUs) and a plurality of digital communication paths according to an example embodiment of the present invention.

Fig. 3.2 shows a block diagram of a split microwave backhaul system with multiple indoor communication units (IDUs), outdoor communication units (ODUs), and multiple digital communication paths, according to an example embodiment of the present invention.

Fig. 4 is a flowchart of exemplary operational steps for communicating signals between an indoor communication unit (IDU) and an outdoor communication unit (ODU) in accordance with an exemplary embodiment of the present invention.

Fig. 5 is a flowchart of exemplary operational steps for communicating signals between an indoor communication unit (IDU) and an outdoor communication unit (ODU) in accordance with an exemplary embodiment of the present invention.

Embodiments of the present invention 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.

Detailed Description

The following detailed description refers to the accompanying drawings to illustrate exemplary embodiments consistent with this invention. References in the detailed description of "one 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 terms do not necessarily refer 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 one skilled in the relevant art to affect such feature, structure, or characteristic in connection with other exemplary embodiments whether or not explicitly described.

Exemplary Split microwave backhaul System

Fig. 1 shows a block diagram of a split microwave backhaul system 100 including an indoor communication unit (IDU) 102 and an outdoor communication unit (ODU) 104, according to an example embodiment of the present invention. Microwave, as used throughout this disclosure, refers to both ground point-to-point wireless communication and point-to-multipoint communication.

The split microwave backhaul system 100 initiates communication by accessing information sources that may include, for example, audio data 106, video data 108, or other data 110 capable of being transmitted over a high capacity IP/ethernet connection. To facilitate this communication, the IDU102 is electrically connected to the core network. In particular, the IDU102 is configured to obtain one or more digital data sequences (e.g., audio data 106, video data 108, data transmitted over a high capacity IP/ethernet connection 110, etc.) from the core network. The IDU102 may also be configured to support several additional services, such as ethernet, TDM, and control data aggregated over a wireless link.

The IDU102 may be implemented at a location substantially removed from the ODU104, such as at a ground level location. For example, the IUD102 may be positioned inside a home or office building or the like. Conversely, the ODU104 may be implemented at a substantially elevated location, such as at the top of a pole, at the top of an antenna tower, or at the top of a building. In certain embodiments, the IDU102 and ODU104 may be separated by a distance of up to about 300 meters.

The IDU102 and ODU104 are connected via a digital communication path 112 (which is configured such that digital data 114 may be transported between the IDU102 and ODU 104). Digital communication path 112 may include an ethernet cable, a fiber optic cable, a coaxial cable, a twisted pair cable, a shielded cable, a category 5 cable, a category 6 cable, or one or more copper wires. In some embodiments, the digital communication path 112 may be a wireless communication channel. Additionally, antenna 116 may be electrically connected to ODU104 and may be positioned substantially proximate to ODU 104. Thus, the split microwave backhaul system 100 is implemented such that digital data 114 can be communicated from the IDU102 to the ODU104 over the digital communication path 112 and then to the antenna 116 (where communication over the wireless link can be initiated thereafter). The split microwave backhaul system 100 is also implemented such that digital data 114 received through an antenna 116 may be communicated from the ODU104 to the IDU102 through a digital communication path 112.

Utilizing digital transport between IDUs and ODUs (versus analog transport for traditional split ODU architectures) provides many advantages. First, transporting digital data 114 over digital communication path 112 provides more efficient communication between IDU102 and ODU 104. In particular, the transmission of digital data 114 over digital communication path 112 (e.g., an Ethernet cable) provides higher bandwidth (bandwidth in the range of about 2.5Gbp to about 10 Gbp). Second, the transmission of digital data 114 over digital communication path 112 reduces signal loss and can be implemented less expensively than the transmission of analog signals. In particular, because the transmission of the digital signal 114 may be adjusted to eliminate any signal loss, signal loss typically associated with the transmission of analog signals may be eliminated. Finally, the advanced split microwave backhaul system 100 can also be configured to support suitable coding and modulation (ACM), which provides high survivability of the digital communication path 112 even in extreme weather.

The split microwave backhaul system 100 can also be configured to provide a high Mean Time Between Failure (MTBF), which refers to the expected time between intrinsic failures of the system during operation. The split microwave backhaul system 100 can also be implemented using existing infrastructure (e.g., ethernet or other existing technology), thus helping to reduce the costs associated with the split microwave backhaul system 100. However, it will be apparent to those skilled in the relevant art that other advantages can be realized without departing from the spirit and scope of the disclosure.

Although the present invention is described in terms of a wired backhaul architecture, those skilled in the relevant art will recognize that the present invention may be applicable to other architectures using wireless or other wired communication methods without departing from the spirit and scope of the present invention.

Exemplary indoor Unit (IDU) and outdoor Unit (ODU)

In an embodiment of the invention, specific functions are offloaded from the ODU104 to the IDU 102. The offloading of functionality provides the split microwave backhaul system 100 with a number of advantages over conventional split ODU architectures. For example, when multiple functions are implemented within the IDU102, the power consumption of the split microwave backhaul system 100 may become more efficient compared to the ODU 104. Similarly, because the IDU102 may be positioned at the ground, while the ODU104 may be positioned at an elevated height (e.g., the top of a pole, antenna tower, etc.), power may be transferred to the IDU102 more easily and less expensively than to the ODU 104. Thus, when a majority of these functional components are implemented in the IDU102 rather than in the ODU104, the required power can be supplied to the aforementioned functional components at a lower cost.

Other advantages of offloading functions from the ODU104 to the IDU102 may be reduced installation and repair costs. A significant portion of the expense associated with typical split ODU structures stems from installation expense. In particular, it is likely difficult to transport all of the required equipment to a physical location of the ODU which may be elevated and thus may be difficult to reach. Similarly, as the number of functional components implemented in an ODU increases, the likelihood that the ODU will require repair actually increases. With typical split ODU configurations, maintenance costs are also typically high because it can be expensive to hire a skilled technician to climb to the elevated location of the ODU for repair when the ODU does need to be repaired. Thus, the split microwave backhaul system 100 can be implemented and maintained at relatively low cost because a substantial portion of the required functionality can be offloaded from the ODU104 to the IDU 102.

Fig. 2 shows a block diagram of an advanced split microwave backhaul system 200 according to an example embodiment of the present invention. The system 200 includes: is coupled to an indoor communication unit (IDU) 202 of an outdoor communication unit (ODU) 204 via a digital communication path 212. IDU202 may represent an exemplary embodiment of IDU102, while ODU204 may represent an exemplary embodiment of ODU 104.

The IDU202 includes a digital modem assembly 210 and a digital interface module 218. Digital modem assembly 210 and digital interface module 218 are configured to prepare digital data 214 to be communicated to ODU204 and received from ODU 204.

In addition, the IDU202 includes a media access control layer (MAC) 206 and a physical layer (PHY) 208. MAC206 is configured to provide addressing and channel access control mechanisms that enable several terminals or network nodes to communicate within a multiple access network that integrates a common medium (e.g., ethernet). PHY208 defines a means for transmitting raw bits (raw bits) rather than logical packets through a digital communication path 212 connecting IDU202 and ODU 204. In particular, the bit stream may be grouped into codewords or symbols and converted into digital data packets that may then be transmitted over the digital communication path 212.

Digital modem component 210 is electrically connected to PHY208 such that digital modem component 210 can transmit and/or receive one or more digital data packets from PHY 208. Digital modem component 210 is configured to perform modulation and demodulation of one or more digital data packets 230. In some embodiments, the digital modem component 210 may actually function as a baseband modem. Further, any noise associated with the IDU202 or the digital communication path 212 may be removed when the digital modem component 210 is implemented in the IDU 202.

The IDU202 can also include a Multiplexer (MUX) 220 that can be electrically connected to the digital modem component 210. The MUX220 may be configured to transmit and/or receive one or more digital data packets 230 from the digital modem component 210. The MUX220 may be further configured to select one of the one or more digital data packets 230 and output the selected digital data packet 232 to the first digital interface module 218. Similarly, the MUX220 may be configured to select a received digital data packet from a plurality of received digital data packets (see fig. 3.1) and output the selected digital data packet to the data modem component 210. Accordingly, the MUX220 may be configured to increase the amount of data that may be sent over the network within a certain amount of time and bandwidth. In addition, the MUX220 may allow one or more digital data packets to share a single digital communication path 212. In one embodiment, the MUX220 may be implemented as part of the digital modem component 210. For example, the digital modem component 210 may operate as a "smart chip" such that the digital modem component 210 not only modulates/demodulates one or more digital data packets 230, but also multiplexes one or more digital data packets 230. As described above, the one or more digital data packets 230 may include audio data, video data, ethernet, or TDM, as examples provided; however, other types of data are possible without departing from the spirit and scope of the present disclosure. Thus, implementing MUX220 within IDU202 eliminates the need to run multiple transfer lines between IDU202 and ODU204, which may also reduce the expense associated with advanced split microwave backhaul system 200.

Digital interface module 218 may be configured to transmit and/or receive selected digital data packets 232 from MUX220 and prepare selected digital data packets 232 to be transmitted as digital data 214 over digital communication path 212. In embodiments where the IDU202 does not include the MUX220 or the MUX220 is implemented within the digital modem component 210, the digital interface module 218 may be configured to transmit and/or receive selected digital data packets 232 from the digital modem component 210. Accordingly, the digital interface module 218 is configured to facilitate the appropriate transmission of digital data 214 to the ODU204 or reception of digital data 214 from the ODU204 over the communications path 212.

ODU204 includes a digital interface module 222, a digital-to-analog converter (DAC) 224, an analog-to-digital converter (ADC) 226, and an RF module 228. The digital interface module 222 of the ODU may actually function similarly to the digital interface module 218 of the IDU. In particular, the digital interface module 222 is configured to facilitate the appropriate transmission of digital data 214 to the IDU202 or reception of digital data 214 from the IDU202 via the digital communication path 212. Digital interface module 222 is also configured to communicate received digital data 214 to DAC224 and receive digital data 214 from ADC 226.

The DAC224 is configured to convert the digital data 214 into first analog data 234 and the ADC is configured to convert the second analog data 236 into the digital data 214. Both DAC224 and ADC226 are electrically connected to RF module 228.

The RF module 228 is configured to receive the first analog data 234 from the DAC 224. The RF module 228 is also configured to perform frequency conversion on the first analog data 234. When the first analog data 234 is received at the RF module 228, the first analog data 234 may have a frequency at baseband. Accordingly, the RF module 228 may convert the analog data 234 from baseband to Radio Frequency (RF) such that the analog data 234 may be transmitted over a wireless link. The RF module 228 then transmits the analog data 234 to the antenna 216, which may be configured to transmit the analog data 234 over a wireless link having a radio frequency. The RF module 228 may also be configured to down-convert the analog data 236 after it has been received over the wireless link via the antenna 216. Specifically, the RF module 228 may down-convert the received analog data 236 from radio frequency to baseband, so the second analog data 236 may be converted to digital data 214 at the ADC 226.

In addition to distributing the aforementioned functional components between IDU202 and ODU204 as described herein, communication interface circuitry may also be offloaded from ODU204 to IDU 202. For example, after offloading additional communication interface circuitry to IDU202, ODU204 may simply include a Low Noise Amplifier (LNA), a Power Amplifier (PA), a duplexer, and an optical-to-electrical-to-optical converter. Accordingly, communication interface circuits such as an N-plexer (N-plexer), one or more synthesizers, and one or more baseband components may be offloaded from ODU 204.

IDU202 and ODU204 are given for illustrative purposes only and, as will be apparent to persons skilled in the relevant art, IDU202 and ODU204 may include additional functionality without departing from the spirit and scope of the present disclosure. In addition, each of the aforementioned functional components implemented in the IDU202 and ODU204 are bi-directional.

Digital communication path 212 may also be configured to operate as a time or frequency division path such that transmit and receive signals may propagate through a single digital communication path 212. For example, digital communication path 212 may be configured to support Time Division Multiplexing (TDM), Time Division Multiple Access (TDMA), or Frequency Division Duplexing (FDD); however, other communication schemes are possible without departing from the spirit and scope of the present disclosure. The digital communication path 212 may also include a plurality of dedicated transmit and receive paths. Thus, the digital communication path 212 may be configured to use a dual channel configuration of adjacent channels, dual channel to non-adjacent channels on a single cable. This dual channel architecture may enable digital communication path 212 to perform single chip cross polarization interference cancellation (XPIC) to further increase its transmission capacity.

In some embodiments, an optical feedback loop may be established over digital communication path 212 for digital predistortion purposes. In particular, suitable digital predistortion schemes may be established over the digital communication path 212 to improve the output power and power consumption of the split microwave backhaul system 100.

In one embodiment, the split microwave backhaul system 100 may be configured to have a high capacity characteristic. For example, the split microwave backhaul system 100 may support frequencies in the range from about 5.92GHz to about 43.5GHz, however, other frequency ranges are possible without departing from the spirit and scope of the present disclosure. Split microwave backhaul system 100 may also support modulation schemes up to about 2048 QAM. Further, the digital communication path 212 may have a link capacity of approximately 112 MHz.

Exemplary Split microwave backhaul System

Fig. 3.1 shows a block diagram of a split microwave backhaul system 300 according to an exemplary embodiment of the present invention. System 300 includes an indoor communication unit (IDU) 302 coupled to a plurality of outdoor communication units (ODUs) 304.1, 304.2, and 304.3 via a plurality of digital communication paths 312.1, 312.2, and 312.3. IDU302 may represent an exemplary embodiment of IDU202, while ODUs 304.1, 304.2, and 304.3 may each represent an exemplary embodiment of ODU 204.

IDU302 may be configured to transmit and/or receive digital data 314.1, 314.2, and 314.3 via a plurality of digital communication paths 312.1, 312.2, and 312.3. Digital communication paths 312.1, 312.2, and 312.3 may each similarly be used as digital communication path 212. In particular, each digital communication path 312.1, 312.2, and 312.3 may be configured to have a dual channel structure and operate as a time or frequency division path. Upon receiving the one or more digital data 314.1, 314.2, and 314.3, digital interface module 218 (see FIG. 2) of IDU302 may output the one or more digital data 314.1, 314.2, and 314.3 to MUX220 (see FIG. 2), respectively. The MUX220 may then be configured to select one of the one or more digital data 314.1, 314.2, and 314.3 and output the selected digital data to the digital modem component 210 (see fig. 2). Additionally, prior to transmitting one or more of the digital data 314.1, 314.2, and 314.3, the MUX220 may take a single digital input and select one of the digital communication paths 312.1, 312.2, or 312.3 to transmit the single digital input.

The MUX220 may be implemented before or after the digital interface module 218. The MUX220 may also be implemented as part of the digital interface module 218 or as part of the digital modem component 210. In some embodiments, IDU302 may not include MUX 220. For example, digital data 314.1, 314.2, and 314.3 may each be communicated between PHY208 (see fig. 2) and their respective ODUs 304.1, 304.2, and 304.3, respectively.

Digital data 314.1, 314.2, and 314.3 may each include substantially similar data to be communicated between IDU302 and ODUs 304.1, 304.2, and 304.3, respectively. The digital data 314.1, 314.2 and 314.3 may also each include different data. For example, desired data may be assigned to each digital data 314.1, 314.2, and 314.3 based on the time desired data is to be transmitted, the relative size of the desired data, the frequency of the desired data, and so forth. Additionally, digital data 314.1, 314.2, and 314.3 may each communicate a different signal type that may be selected from, by way of example, a transmit signal, a receive signal, a transmit control, a receive control, or a DC signal.

Referring also to fig. 3.2, there is shown a split microwave backhaul system 320 having a plurality of indoor communication units (IDUs) 322.1, 322.2 and 322.3, as well as an outdoor communication unit (ODU) 324 and a plurality of digital communication paths 332.1, 332.2 and 332.3 in accordance with an exemplary embodiment of the present invention. IDUs 322.1, 322.2, and 322.3 may each represent an exemplary embodiment of IDU202, while ODU324 may represent an exemplary embodiment of ODU 204.

ODU324 may be configured to transmit and/or receive digital data 334.1, 334.2, and 334.3 via a plurality of digital communication paths 332.1, 332.2, and 332.3. The digital communication paths 312.1, 312.2, and 312.3 may each represent an exemplary implementation of the digital communication paths 312.1, 312.2, and 312.3, respectively. ODU324 may include a second MUX that behaves substantially similar to MUX 220. Specifically, upon receiving one or more of the digital data 334.1, 334.2, and 334.3, the second digital interface module 222 (see fig. 2) may independently output the one or more digital data 334.1, 334.2, and 334.3 to the second MUX. The second MUX may be configured to select one of the one or more digital data 334.1, 334.2, and 334.3 and output the selected data to the DAC224 (see fig. 2). Additionally, prior to transmitting the one or more digital data 334.1, 334.2, and 334.3, the second MUX may take a single digital input from the ADC226 (see fig. 2) and select one of the digital communication paths 332.1, 332.2, and 332.3 to transmit the single digital input.

The second MUX may be implemented anywhere in ODU 324. Additionally, each functional component included in ODU324 may be configured to independently input and/or output one or more digital data 334.1, 334.2, and 334.3, respectively, depending on where the second MUX is implemented in ODU 324. The second MUX may also be configured to output digital data 334.1, 334.2, and 334.3 to ADC226 and input digital data from DAC 224. The second MUX may also be implemented as part of the second digital interface module 222 or as part of the RF module 228. The ODU324 may also include two separate second MUXs, one of which is electrically connected to the DAC224 and the other of which is electrically connected to the ADC 226. In some embodiments, ODU324 does not include a second MUX. For example, digital data 334.1, 334.2, and 334.3 may be communicated independently between antenna 326 and their respective IDUs 322.1, 322.2, and 322.3.

ODUs 304.1, 304.2, and 304.3 and IDUs 322.1, 322.2, and 322.3 are provided for purposes of example only, and are not intended to be the only ODUs and IDU capable of use herein, and are not meant to limit the present disclosure. In particular, any number of ODUs and IDUs may be connected to a single respective IDU and ODU without departing from the spirit and scope of the present disclosure.

Between indoor unit (IDU) and outdoor unit (ODU)Exemplary method of communicating signals

Fig. 4 is a flowchart of an exemplary method for communicating signals between an indoor communication unit (IDU) and an outdoor communication unit (ODU) according to an exemplary embodiment of the present invention. The flow diagram of fig. 4 is described with reference to the embodiment of fig. 2. However, the method 400 is not limited to these embodiments.

The method 400 begins at step 402 where digital data is received from the core network at the IDU 202. The digital information may include audio data, video data, and/or any other data capable of being communicated over a high capacity IP/ethernet connection. The digital information passes through MAC206 and PHY208, which breaks the digital information into codewords or symbols and converts the digital information into digital data packets 230 that can be communicated over digital communication path 212.

In step 404, the digital data packet 230 is modulated by the digital modem component 210.

At step 406, it is determined whether IDU202 includes MUX 220. If the IDU includes the MUX220, the method proceeds to step 408. If the IDU202 does not include the MUX220, the digital data packet 230 is passed from the digital modem 210 to the first digital interface module 218.

At step 408, the digital data packet 230 is multiplexed or demultiplexed and transmitted to the first digital interface module 218.

At step 410, the first digital interface module 218 prepares the digital data packet 230 to be communicated as digital data 214 over the digital communication path 212.

At step 412, digital data 214 is communicated between digital interface module 218 of the IDU and digital interface module 222 of the ODU over digital communication path 212. Digital interface module 222 then transfers digital data 214 to DAC 224.

At step 414, the digital data is converted to the first analog data 234 by the DAC 224.

At step 416, the first analog data 234 is up-converted from baseband to radio frequency by the RF module 228. The up-conversion is performed such that the first analog signal can be transmitted over the wireless link via the antenna.

Fig. 5 shows a flowchart of a method for communicating signals between an indoor communication unit (IDU) and an outdoor communication unit (ODU) according to an exemplary embodiment of the present invention. The flow chart of fig. 5 is described with reference to the embodiment of fig. 2. However, the method 500 is not limited to these embodiments.

The method 500 begins at step 502 where analog data 236 is received from the antenna 216 after being transmitted over the wireless path.

At step 504, the received analog data 236 is down-converted from radio frequency to baseband by the RF module 228. This down conversion is performed so that digital-to-analog conversion can be performed on the second analog data 236.

At step 506, the analog data 236 is converted to digital data 214 by the ADC 226.

At step 508, it is determined whether the ODU204 includes a second MUX. If the ODU204 includes a second MUX, the method proceeds to step 510. If the ODU204 does not include a second MUX, the digital data packet 214 is passed from the ADC226 to the digital interface module 222.

At step 510, the digital data 214 is multiplexed or demultiplexed and transferred to the second digital interface module 222.

At step 512, the digital interface module of ODU222 prepares digital data to be communicated over digital communication path 212.

At step 514, digital data 214 is communicated between digital interface module 222 of ODU and digital interface module 218 of IDU202 over digital communication path 212. The digital interface module 218 then passes the digital data 214 to the digital modem 210 as digital data packets 230.

At step 516, the digital data packet 230 is demodulated by the digital modem component 210 so that the digital data packet 230 can then be communicated to the core network.

Conclusion

The exemplary embodiments described herein are provided for purposes of illustration and not limitation. Other exemplary embodiments are possible, and variations may be made to the exemplary embodiments within the spirit and scope of the invention. The detailed description is, therefore, not to be taken in a limiting sense. Rather, the scope of the invention is to be defined only by the claims appended hereto, and by their equivalents.

Embodiments of the invention may be implemented in hardware, firmware, software, or a combination thereof. Embodiments of the invention are also implemented as instructions stored on a machine-readable medium, which may be read and executed by one or more processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer device). For example, a machine-readable medium may include Read Only Memory (ROM); random Access Memory (RAM); a magnetic disk storage medium; optical storage media, flash memory devices; electrical, optical, acoustical or other form of propagated signals (e.g., carrier waves, infrared rays, digital signals, etc.), and others. Further, firmware, software, routines, instructions are described herein as performing certain actions. However, it should be understood 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.

It is to be understood that the detailed description section, and not the abstract section, is intended to be used to interpret the claims. The abstract section may set forth one or more, but not all embodiments of the invention, and is therefore not intended to limit the invention and the appended claims in any way.

The invention has been described with the aid of functional blocks illustrating the implementation of specific functions and their relationships. Boundaries of these functional blocks have been arbitrarily defined for the convenience of the description. Alternative boundaries may be defined so long as the specified functions and relationships thereof are appropriately performed.

It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the present invention 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.

Claims (10)

1. An indoor communication unit in a split backhaul architecture, comprising:

a digital modem component configured to modulate and demodulate digital data; and

a digital interface module coupled to the digital modem assembly, the digital modem assembly configured to communicate the digital data between the indoor communication unit and an external outdoor communication unit over a wireless digital communication path, wherein the wireless digital communication path is configured as an optical feedback loop for digital predistortion;

the wireless digital communication path is configured to establish an adaptive digital predistortion scheme to improve the output power and power consumption of the split backhaul architecture.

2. The indoor communication unit of claim 1, further comprising a multiplexer device.

3. The indoor communication unit of claim 1, wherein the wireless digital communication path is configured to support a bandwidth in the range of 2.5Gbp to 10Gbp or the wireless digital communication path is a time and frequency division path.

4. The indoor communication unit of claim 1, further comprising one or more additional digital communication paths, each additional wireless digital communication path configured to communicate the digital data between the indoor communication unit and the outdoor communication unit and one or more additional outdoor communication units.

5. A split backhaul communication system, comprising:

an outdoor communication unit comprising:

a digital interface module configured to communicate digital data between the outdoor communication unit and an external indoor communication unit over a wireless digital communication path;

a digital-to-analog converter coupled to the digital interface module;

an analog-to-digital converter; and

an RF module configured to convert analog data from baseband to radio frequency; and

an indoor communication unit comprising:

a digital modem component configured to modulate and demodulate digital data; and

a second digital interface module coupled to the digital modem assembly, wherein

The wireless digital communication path is configured to communicate the digital data between the indoor communication unit and the outdoor communication unit and as an optical feedback loop for digital predistortion;

the wireless digital communication path is configured to establish an adaptive digital predistortion scheme to improve output power and power consumption of the split backhaul communication system.

6. The split backhaul communication system of claim 5, further comprising a multiplexer device.

7. The split backhaul communication system of claim 5, wherein the wireless digital communication path is configured to be a dual channel path or an optical feedback loop.

8. The split backhaul communication system of claim 5, further comprising one or more additional wireless digital communication paths, each additional wireless digital communication path configured to communicate the digital data between the outdoor communication unit and the indoor communication unit and one or more additional indoor communication units.

9. A method for communicating data over a split microwave backhaul system, comprising:

receiving, at a first data interface module located at the outdoor communication unit, modulated digital data from a second digital interface module located at the indoor communication unit over a wireless digital communication path;

establishing an optical feedback loop through the wireless digital communication path;

performing an adaptive digital predistortion scheme through the wireless digital communication path to improve output power and power consumption;

at the outdoor communication unit, canceling noise within the modulated digital data, wherein the noise is associated with at least one of the indoor communication unit and the wireless digital communication path;

converting, at the outdoor communication unit, the modulated digital data to analog data; and

at the outdoor communication unit, the analog data is converted from baseband to radio frequency over a wireless link.

10. The method of claim 9, further comprising:

receiving, at the outdoor communication unit, the analog data from an antenna;

down-converting the analog data from radio frequency to baseband at the outdoor communication unit;

converting, at the outdoor communication unit, the analog data to digital data;

multiplexing the digital data; and demodulating, at the indoor communication unit, the digital data.