Initiating wideband simultaneous transmit and receive communications

A protocol for initiating communications between STAR devices in a network includes communicating via a communication device having a transmit signal path and a receive signal path where the transmit signal path and receive signal path are operable to transmit and receive simultaneously at the same frequency over an interference-suppressed band. A communication sub-band and an initiation sub-band are generated within the interference-suppressed band. The initiation sub-band has a lower bandwidth than the communication sub-band. Signals may be transmitted and received signals over the initiation sub-band the communication sub-band.

FIELD

This relates to the field of communications and, more particularly, to communications between simultaneous transmit and receive (STAR) devices.

BACKGROUND

Communication devices communicate with each other over a frequency band in the radio or microwave frequency range. To prevent interference between devices, government agencies regulate the frequency bands that are available. Unfortunately, because frequency bandwidth is set by the laws of physics, new bandwidth cannot be created. To overcome this obstacle, people have learned to use frequency bands efficiently. But, because the demand for wireless communication and the amount of data being transmitted is increasing, there is a need to increase the number of users assigned to a particular band.

Radio communications take place on a prescribed band or channel within the spectrum. In order for data to be transmitted and received by radio devices, the channel is often divided into a transmission band and receiving band, which requires more bandwidth than would be required if the data could be transmitted and received over the same band simultaneously.

In recent years, people have developed wireless devices, called STAR devices, that can simultaneously transmit and receive at same frequency. If these STAR devices could be used in modern communication networks, such as radio or cellular networks, they would free significant amounts of bandwidth. STAR devices have, however, found limited commercial use because they are usually narrowband and made for specialized purposes.

BRIEF SUMMARY

It would be beneficial to find a way to use STAR devices in modern communication networks to free bandwidth that could be used for other purposes. The devices, methods, and systems described here permit such use of STAR devices and set forth an advantageous protocol for initiating wideband simultaneous transmit and receive communications.

An example of a communication device includes a transmit signal path and a receive signal path. The transmit signal path and receive signal path are operable to transmit and receive simultaneously at the same frequency over an interference-suppressed band. Processing circuitry is configured to generate a communication sub-band and an initiation sub-band within the interference-suppressed band. The initiation sub-band has a lower bandwidth than the communication sub-band. The processing circuitry is also configured to transmit and receive over the initiation sub-band and transmit and receive over the communication sub-band.

The communication device may further include one or more of the following features.

The communication device may further include an interference suppressor that suppresses interference between the transmit signal path and receive signal path to form the interference-suppressed band.

The initiation sub-band may operate at a lower power than the communications sub-band.

The communication sub-band may be at least 75% of the bandwidth of the interference-suppressed band.

The initiation sub-band may include a first frequency range higher than the communication sub-band and a second frequency range lower than the communication sub-band.

The processing circuitry may be further configured to transmit a polling signal and receive a remote polling signal simultaneously at the same frequency in the initiation sub-band.

The processing circuitry may be configured to transmit and receive over the communication sub-band simultaneously at the same frequency.

The signals transmitted in the initiation sub-band may be lower power than a baseline power of the communication sub-band.

An example of a communication method includes communicating via a communication device having a transmit signal path and a receive signal path where the transmit signal path and receive signal path are operable to transmit and receive simultaneously at the same frequency over an interference-suppressed band. The method includes generating a communication sub-band and an initiation sub-band within the interference-suppressed band where the initiation sub-band has a lower bandwidth than the communication sub-band. The method also includes transmitting and receiving signals over the initiation sub-band and transmitting and receiving signals over the communication sub-band.

This communication method may further include one or more of the following features.

The communication may further include forming the interference-suppressed band by suppressing interference between the transmit signal path and receive signal path.

The initiation sub-band may operate at a lower power than the communications sub-band.

The communication sub-band may be at least 75% of the bandwidth of the interference-suppressed band.

The initiation sub-band may include a first frequency range higher than the communication sub-band and a second frequency range lower than the communication sub-band.

The communication method may further include transmitting a polling signal and receiving a remote polling signal simultaneously at the same frequency in the initiation sub-band.

The processing circuitry may be configured to transmit and receive over the communication sub-band simultaneously at the same frequency.

Signals transmitted in the initiation sub-band may be lower power than a baseline power of the communication sub-band.

Another example of a communication method includes facilitating a communication network between a plurality of communication devices having a transmit signal path and a receive signal path, where the transmit signal path and receive signal path are operable to simultaneously transmit and receive at the same frequency over an interference-suppressed band, by (a) generating a communication sub-band and an initiation sub-band within the interference-suppressed band where the initiation sub-band has a lower bandwidth than the communication sub-band; (b) executing a polling stage in which a first communication device transmits a polling signal within the initiation sub-band to a second communication device; (c) executing an interrogation stage in which the first communication device transmits an interrogation signal within the initiation sub-band to the second communication device; (d) executing an authenticating stage in which the first communication device transmits a timing signal to the second communication device; and (e) executing a communication stage based on the timing signal in which the first and second communication devices communicate by transmitting and receiving simultaneously at the same frequency.

This communication method may further include one or more of the following features.

The interference-suppressed band may be formed by suppressing interference between the transmit signal path and receive signal path.

The initiation sub-band may operate at a lower power than the communications sub-band.

The communication sub-band may be at least 75% of the bandwidth of the interference-suppressed band.

The initiation sub-band may include a first frequency range higher than the communication sub-band and a second frequency range lower than the communication sub-band.

The communication method may further include, simultaneously at the same frequency in the initiation sub-band, transmitting a polling signal by the first communication device and receiving by the first communication device a polling signal from the second communication device.

The processing circuitry may be configured to transmit and receive over the communication sub-band simultaneously at the same frequency.

Signals transmitted in the initiation sub-band may be lower power than a baseline power of the communication sub-band.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

This disclosure describes exemplary embodiments, but not all possible embodiments of the devices, systems and methods. Where a particular feature is disclosed in the context of a particular example, that feature can also be used, to the extent possible, in combination with and/or in the context of other examples. The devices, systems, and methods may be embodied in many different forms and should not be construed as limited to only the examples described here.

Referring toFIG.1, a communications network100may include at least one base station102that communicates with at least one mobile unit104. The base station102is a fixed-location point of communication for devices within the network. The base station102receives and transmits signals in the network to devices such as mobile units104.

A mobile unit104may be a mobile communication device such as cellular phone, tablet, computer, radio, and the like. The mobile unit104may include the typical hardware and software components one would find in modern mobile communication devices, such as a processor, memory, a keypad, a screen, and I/O ports, among others. In any example, the mobile unit104is a device capable of receiving and transmitting radio frequency signals wirelessly.

In the communications network, the base station102may communicate with the mobile units104and mobile units104may communicate with other mobile units104and base stations102as illustrated by the arrows inFIG.1.

The network may be a wired or wireless network that operates using radio frequency communications technology such as a radio network, cellular network, computer network, Internet network, or the like.

Referring toFIG.2, an example of communication device200useful in such a communication network100and other types of communication networks will now be described.

The communication device200includes at least one antenna202in signal communication with a transmit signal path204and a receive signal path206. The communication device200also includes an interference suppressor208and processing circuitry210. In the communication network100, the base stations102and mobile units104may be equipped with a communication device200described here.

The antenna202may be a radio antenna capable of transmitting and receiving radio signals. Conventional antennae may be used to serve this purpose. In some examples of the communication device200, a single antenna can perform the transmit and receive functions of the communication device200. In other examples, the antenna202may be composed of a separate transmit antenna and a receive antenna, or an antenna array with multiple apertures.

The transmit signal path204and receive signal path206are signal propagation pathways through which a transmitted signal and a received signal travels, respectively. These pathways may include conventional coaxial lines, waveguides, directional couplers, and signal conditioning equipment. The transmitted signal may be generated by a radio transmitter211, travel through the transmitted signal path204, and be transmitted from the antenna202. The received signal may be received by the antenna202, travel through the receive signal path206, and be received by a radio receiver212.

The transmit signal path204and receive signal path206are operable simultaneously at the same frequency. This permits them to transmit and receive at the same frequency at the same time so that the communication device200is a STAR device. In a conventional radio, this is not possible because the receive signal path204will receive interference from the signal being transmitted via the transmit signal path204.

The components of the communication device200may vary depending on its purpose. Those skilled in the art will understand how to make the communication device200and/or modify an existing conventional device to transform it into a communication device200after having the benefit of reading this disclosure.

To permit simultaneous transmission and reception at the same frequency, the interference suppressor208is operable to cancel interference noise from the transmit signal path204in the receive signal path206over a interference-suppressed band. This effectively reduces same frequency interference between the transmit signal path204and receive signal path206so that the receiver212can hear the desired transmission from a different communication device200rather than interference from the same communication device's200transmitted signal.

As used herein, “noise” refers to the background signal at the receiver212at the frequency range of interest prior to interference suppression. Interference suppression reduces the noise by suppressing interference caused by a signal being transmitted at the same time and same frequency as a signal that is being received.

Interference suppressors208useful for simultaneous transmit and receive devices are known and may be used as the interference suppressor208discussed here. Examples of such interference suppressors are described by Nwankwo et al in “A Survey of Self-Interference Management Techniques for Single Frequency Full Duplex Systems,”IEEE Access, Vol. 6, pp. 30242-30268 (2018). Other examples of interference suppressors208that may be used in the communication device200are disclosed in U.S. Pat. Nos. 7,633,435, 8,879,433, 9,209,840, 9,461,698, 9,692,469, 10,218,490, and EP 2868004. The type of communication device200and interference suppressor208giving it STAR capability is not limited to any particular STAR device. Conventional STAR devices may be used and adapted to function with the network100using the initiation protocol described herein.

The problem with using simultaneous transmit and receive communication devices in a network is that no protocol is currently in place for initiating a communication between communication devices200operating in the network100as there would be with conventional radio communication devices in a cellular network, for example. The processing circuitry210is configured to provide this function.

Referring toFIG.3, the processing circuitry210includes a computer processor213and machine readable memory214that stores program instructions executed by the processor213.

Referring toFIGS.2-4, the processing circuitry210is configured to generate a communication sub-band220and an initiation sub-band222within the interference-suppressed band217. The initiation sub-band222may have a lower bandwidth than the communication sub-band220and may operate at a lower power than the communication sub-band220. As illustrated inFIG.4, the interference suppression relative to the background noise, labeled inFIG.4, over the initiation sub-band222may be greater than the interference suppression relative to the background noise over the communication sub-band220. The power at which the initiation sub-band222and communication sub-band220operate is within the background noise power, which makes communications less detectable by third parties.

The processing circuitry210is also configured to transmit and receive over the initiation sub-band224and transmit and receive simultaneously at the same frequency over the communication sub-band220as described below.

As illustrated inFIG.4, the interference-suppressed band217is the band or frequency range over which the interference suppressor208and interference suppression module216operate. In a specific example, the interference suppressor208operates over an instantaneous bandwidth of up to 1 GHz over the 3 MHz to 60 GHz range.

Referring toFIGS.3and4, an interference suppression module216includes program instructions that define the interference-suppressed band217, which is the band over which the interference suppressor208operates. For example, if the interference suppressor208operates over a range of 1 GHZ, the interference-suppressed band is the 1 GHz range in which the interference suppressor208cancels interference from the transmit signal path204in the receive signal path206.

A sub-band generation module218generates a communication sub-band220and an initiation sub-band222within the interference-suppressed band217.

The initiation sub-band222has a lower bandwidth than the communication sub-band220and may operate at a lower power than the communication sub-band220. The bandwidth of the communication sub-band220is at least 75% of the bandwidth of the interference-suppressed band217.

The initiation sub-band222may be distributed over two separate bands within the interference-suppressed band217. The initiation sub-band222may include a first frequency range that is higher than the communication sub-band220and a second frequency range that is lower than the communication sub-band220.

The communication sub-band220may operate at a lower power than the noise over the interference-suppressed band217. This function makes communications within the communication sub-band220extremely difficult to detect for conventional radio devices, thereby permitting secure communications.

The initiation sub-band222may be used by the processing circuitry210for transmitting a polling signal224to other communication devices200in the network100. The polling signal224informs the other communication devices200that the communication device transmitting the polling signal224desires to transmit/receive data to/from another communication device200via the communication sub-band220.

The polling signal224may have many different forms including one or more pulses of a pre-defined power, duration, sequence, and delay time between pulses in a sequence, and modulation schemes. If desired, each communication device200may have its own unique polling signal224, that functions like an identification of that particular communications device200. Because the polling signal224is transmitted in the initiation sub-band222, it can have lower power but still be detectable by the other communication devices200. The polling signal224may be relatively low power, such as being about 10% power above the noise floor of the frequency the polling signal224occupies.

The second communication device200that receives the polling signal224may transmit its own polling signal224at the same frequency at the same time as the first communication device200. The communication devices200in the network100are able to simultaneously transmit their own polling signals224and receive polling signals224from other communication devices200at the same time and at the same frequency.

The initiation sub-band222may be also used by the processing circuitry210for transmitting an interrogation signal226to another communication devices200in the network that acknowledged receiving the polling signal224. The interrogation signal226is the second stage of initiating communications over the communication sub-band220. The interrogation signal226may be relatively low power, such as being about 10% power above the noise floor of the frequency the interrogation signal226occupies.

The interrogation signal226tells communication devices200communicating within the network100after having exchanged polling signals224that each of the communication devices200is permitted to communicate within the network100.

The interrogation signal226may have many different forms including one or more pulses of a pre-defined power, duration, sequence, and delay time between pulses in a sequence, and modulation schemes. If desired, each communication device200may have its own unique interrogation signal226, that further identifies that particular communications device200beyond the polling signal224. Because the interrogation signal226is transmitted in the initiation sub-band222, it can have lower power but still be detectable by the other communication devices200.

The interrogation signal226may be transmitted at a different frequency than the polling signal224. The communication devices200in the network100are able to simultaneously transmit their own interrogation signals226and receive interrogation signals226from other communication devices200at the same time and at the same frequency.

After two communication devices200have exchanged interrogation signals226, they are able to confirm each is permitted to communicate within the network100, the initiation sub-band222may be also used by the processing circuitry210for transmitting an authentication signal228to the other communication device200.

The authentication signal228allows each communication device200to identify the communication device200attempting to communicate with it. This may be accomplished by each communication device200having stored thereon the unique authentication signal228of each communication device200authorized to use the network100.

The authentication signal228may have many different forms including one or more pulses of a pre-defined power, duration, sequence, and delay time between pulses in a sequence, and modulation schemes. Because the authentication signal228is transmitted in the initiation sub-band, it can have lower power but still be detectable by the other communication devices200.

The authentication signal228synchronizes the communication devices200so that they are operating at substantially the same time scale. The processing circuitry210generates a timer that defines the time the communication devices200will be able to communicate over the communication sub-band220. The timer may set a countdown time defined by a timing source. The timing source may be an internal clock or an external clock such as a Global Positioning System time clock.

The authentication signal228may be transmitted at a different frequency than the polling signal224or interrogation signal226. The communication devices200in the network100are able to simultaneously transmit their own authentication signals228and receive authentication signals228from other communication devices200at the same time and at the same frequency.

Once the countdown timer ends, both communication devices200are able to transmit and receive data over the wideband communication sub-band220. Because both devices are able to transmit and receive at the same frequency, the communication sub-band220allows for full duplex communication at the same frequency. Unlike conventional radio networks, it is not necessary to divide the communication sub-band220into separate transmit and receive bands. It is also not necessary to use guard bands.

Referring toFIG.5, the communication devices200in the network100are in communication with a network controller300. The network controller includes a computing device310having machine readable memory312storing program instructions that a computer processor314executes to perform control operations on the network100. The network controller300may be a dedicated device physically separate from any of the communication devices200or it may be part of one or more of the communication devices200.

The memory312stores authorized user tables316. The authorized user tables316include a list of the communication devices200that are authorized to communicate over the network100. It may also store the polling signal224and interrogation signal226unique to each communication device200so that they can be used to identify a particular communication device200.

The memory312stores network structure controls318. The network structure controls318may include the network spectrum definition, channel loading protocols, Delay or Disruption Tolerant Network (DTN) protocols and priority, and Software Defined Radio (SDR) and Software Defined Networking (SDN) protocols for the network100.

The memory312stores a cryptography controller320. The cryptography controller includes program instructions to assign frequency key codes and perform over the air re-keying of the communication devices200.

The memory312stores network performance controls322. The network performance controls322includes program instructions to monitor network performance and perform network optimization routines. The network performance controls322also include program instructions executed by the communication devices200for operating the interference suppression module216and sub-band generation module218.

The memory312stores out of network controls324. The out of network controls324include program instructions for handling communications from devices that are not capable of simultaneously transmitting and receiving at the same frequency.

The network controller300is in communication with the communication devices200. Network control functions may be synchronized over similar or dissimilar networks via secure messaging. In this case, being synchronized means the network controller300shares its data and functions with communications devices200across the network.

Referring toFIG.6, an example of communication method400that may employ any of the aforementioned features is now described.

At block402, the method400includes communicating via a communication device, such as communication device200having a transmit signal path204and a receive signal path206. The transmit signal path204and receive signal path206are operable to transmit and receive simultaneously at the same frequency over the interference-suppressed band217.

At block404, the method400further includes generating a communication sub-band220and an initiation sub-band224within the interference-suppressed band217. The initiation sub-band224has a lower bandwidth than the communication sub-band220.

At block406, the method400further includes transmitting and receiving signals over the initiation sub-band224. This may be achieved as described above.

At block408, the method400further includes transmitting and receiving signals over the communication sub-band220. Communication may be achieved over the initiation sub-band224and communication sub-band220between different communication devices200simultaneously and at the same frequency.

Referring toFIG.7, another example of a communication method is described in terms of exemplary stages of initiating data communication between communication devices200in the network100. These stages are executed by the communication devices200using program instructions executed by their processing circuitry210.

In the polling stage, communication devices200are transmitting their respective polling signals224, effectively looking for another communication device200with which to communicate. The polling signals224may be transmitted and received simultaneously at the same frequency.

In the interrogating stage, subsequent to the polling stage, the communication devices200exchange their respective interrogation signals226, which may be transmitted and received simultaneously at the same frequency. During the interrogating stage, the communication devices200, are able to confirm whether the other communication device200is capable of simultaneous transmission and reception (STAR) at the transmitted and received simultaneously at the same frequency.

In the authenticating stage, subsequent to the interrogating stage, the communication devices200transmit and receive their respective authentication signals228, which may be transmitted and received simultaneously at the same frequency. During this stage, the communication devices200become time synchronized and the timing countdown begins.

After the timing countdown ends, the communicating stage commences. During the communication stage, the communication devices200transmit and receive data between each other over the communication sub-band220. During this stage, large amount of data may be exchanged because the communication sub-band220has a large bandwidth. During the communication stage, the communication devices200may transmit and receive data simultaneously at the same frequency.

Referring toFIG.8, parts of the communication stages are summarized as a function of time. Beginning at the earlier time on the left, communication device A200enters the polling stage and begins searching for another communication device B200with which to communicate. After the interrogation stage, communication device B200agrees to communicate with communication device A200. During the authentication stage, the countdown, represented by ΔT1 begins. At the end of the countdown, two way full duplex same frequency data communications begin on the communication sub-band220.

After communication device A200has completed its communication, it requests to stop communicating by sending communication device B200a stop communications signal. Once communication device B200agrees, another countdown, represented by ΔT2 begins. After the second countdown expires, two way communication ends and the communication sub-band220goes quiet.

The stop communication signal may also be transmitted when insufficient quality of service, link quality, or signal strength is detected by a communication device200and/or network controller300.

In some implementations, the devices, systems, and methods described here enable full duplex, wideband (>500 MHZ) communications within the same frequency at the same time through the use of STAR technology. High data rate (wide bandwidth), full duplex communication on the same frequency with almost no latency impact is a significant spectrum management and communications security improvements. Communications using STAR technology creates a fundamentally new approach to secure communications.

The technology discussed here may be used in the telecommunication abstraction layers defined by the International Organization for Standardization in their Open Sessions Connection (OSI) model.

Traditional communications systems have relied on various simplex (one user on a single frequency, channel or time slot at one time) methods for establishing, authenticating and maintaining communications. Since full duplex STAR communications set a new paradigm for the physical (base or first) layer of the OSI model, the existing methods and technologies for several of the other layers may become obsolete as the core assumption of simplex communication is no longer applicable.

The technology described here includes new physical and datalink initiation methodology for wideband simultaneous transmit and receive communications. The methodology is designed as a base abstraction layer of communications protocols for STAR as applied to static and mobile ad hoc network (MANET) communications between two or more STAR-enabled communication devices200.

In some examples, the full duplex STAR communications over the communication sub-band220will not occupy more than 400 megahertz (MHz) of a 500 MHz wideband STAR system, or 900 MHz of a 1 gigahertz (GHz) STAR system. The remaining 100 MHz is not required as a guard band, but rather is employed as the signaling space (free space) for initiating secure physical and datalink initiation activity in the initiation sub-band222.

Due to the deep self-interference suppression provided by the communication devices200, the signals over the initiation222and communication220sub-bands may be contained within the background RF noise. This makes communications over the network100secure because they are extremely difficult to detect. The polling signals224, interrogation signals226, and authentication signals228may be power modulated to be just above or at the noise floor for the radio frequency environment that they occupy. If they were detected by a third party with conventional radio communication equipment, they would appear to be a spurious, short duration noise signal. Since they do not operate in the same frequencies as the communication sub-band, they could not be readily identified as a signal from a communication device200.

This disclosure describes certain example embodiments, but not all possible embodiments of the devices, systems, and methods. Where a particular feature is disclosed in the context of a particular embodiment, that feature can also be used, to the extent possible, in combination with and/or in the context of other embodiments. The devices and associated methods may be embodied in many different forms and should not be construed as limited to only the embodiments described here.