CN105430748B

CN105430748B - Method of operating a wireless communication device and an eNodeB base station

Info

Publication number: CN105430748B
Application number: CN201610034475.1A
Authority: CN
Inventors: J·C·哈特森
Original assignee: Sony Ericsson Mobile Communications AB
Current assignee: Sony Mobile Communications AB
Priority date: 2010-10-19
Filing date: 2010-10-19
Publication date: 2020-05-15
Anticipated expiration: 2030-10-19
Also published as: CN105430748A

Abstract

Methods of operating a wireless communication device and an eNodeB base station. A wireless communication device comprising: a first Radio Frequency (RF) transceiver configured to transmit/receive RF signals in a first frequency band; a second RF transceiver configured to transmit/receive RF signals in a second frequency band different from the first frequency band; and a connection manager coupled to the first and second RF transceivers for assisting channel selection of the first and second RF transceivers to reduce mutual interference between the first and second RF transceivers. Related methods are also disclosed.

Description

Method of operating a wireless communication device and an eNodeB base station

The present application is a divisional application of the inventive patent application having application number 201080069537.3, international application number PCT/IB2010/002678, application date 2010, 10/19, entitled "mobile assisted channel selection in a device having multiple radio transceivers".

Technical Field

The present invention relates to mobile assisted channel selection in a device having multiple radio transceivers.

Background

Wireless communication devices, such as mobile phones, include an increasing number of different RF transceivers (radios) to support access to several wireless communication services, such as cellular access, local access (e.g., WiFi), ad-hoc connections (such as bluetooth), and positioning, such as through the Global Positioning System (GPS). Cellular radios operate in licensed bands defined by 3 GPP. Both WiFi and bluetooth operate in the unlicensed industrial-scientific-medical (ISM) bands around 2.4GHz and 5 GHz. Given the close physical similarity of transceivers in these devices (referred to herein as co-location) and the ever-increasing similarity between the operating frequencies of these transceivers (frequency domain), interaction between radios becomes more likely, which can lead to detrimental performance effects.

With the continued success of cellular communications, both voice and data, frequency planning and regulatory bodies are constantly seeking more available spectrum. New cellular radio bands are becoming unknowingly close to existing bands used as local connections. For example, the universal mobile telecommunications system UMTS band 40 (2300-2400 MHz) and UMTS band 7 (2500-2690 MHz) are very close to the 2.4GHz ISM band (2400-2483.5 MHz), and co-location problems become more likely and potentially leading to mutual interference and/or jamming problems between transceivers operating in different frequency bands. The transmit signal of a high power wireless transceiver may affect the sensitivity of some radio receivers. This requires steep filtering (increasing cost, power and size) as the channels become closer in frequency, but may nevertheless fail when the filter does not protect the bandwidth for roll-off. For example, between band 40 and the 2.4GHZ ISM band, there is no protection bandwidth that can be provided.

Disclosure of Invention

A wireless communication device according to some embodiments comprises: a first Radio Frequency (RF) transceiver configured to transmit/receive RF signals in a first frequency band; a second RF transceiver configured to transmit/receive RF signals in a second frequency band different from the first frequency band, and a connection manager coupled to the first and second RF transceivers for assisting channel selection of the first and second RF transceivers to reduce mutual interference between the first and second RF transceivers.

The first RF transceiver may be configured to transmit first channel allocation information to the connection manager instructing the first RF transceiver to transmit and/or receive a first channel of RF communication signals, and the second RF transceiver may be configured to transmit second channel allocation information to the connection manager instructing the second RF transceiver to transmit and/or receive a second channel of RF communication signals. The connection manager may be configured to analyze the first channel allocation information and the second channel allocation information to determine whether there is potential mutual interference between RF communication signals transmitted/received on the first channel and RF communication signals transmitted/received on the second channel.

In response to determining that there may be potential mutual interference between the RF communication signals transmitted/received on the first channel and the RF communication signals transmitted/received on the second channel, the connection manager may be configured to transmit a channel reselection signal to the first RF transceiver and/or the second RF transceiver instructing it to select a different channel for transmitting/receiving RF communication signals.

In response to receiving the channel reselection signal, the first RF transceiver and/or the second RF transceiver may be configured to send a channel adjustment request to a remote network access point requesting allocation of a new channel to transmit/receive RF communication signals.

The channel adjustment request may include a Channel Quality Indicator (CQI) indicating that the allocated channel quality is not good.

The first RF transceiver may be configured to transmit/receive RF signals in the first frequency band according to a first wireless communication protocol, and the second RF transceiver may be configured to transmit/receive RF signals in the second frequency band according to a second wireless communication protocol that may be different from the first wireless communication protocol.

The first RF transceiver may comprise a bluetooth transceiver and may be configured to select a frequency hopping carrier that does not conflict with frequencies used by the second RF transceiver.

The connection manager may be configured to: determining that potential mutual interference may exist between the first channel and the second channel in response to the first channel being less than an R Hertz distance from the second channel, wherein R is determined in response to a front end filter characteristic of the first RF transceiver and the second RF transceiver.

The connection manager may be configured to: determining that there may be potential mutual interference between the first channel and the second channel if the first channel and an edge of the second frequency band may be separated by a distance less than R Hertz, where R is equal to a width of a 30dB roll-off point of a band filter in the first RF transceiver or the second RF transceiver.

The connection manager may be configured to: determining that there may be potential mutual interference between the first channel and the second channel if the first channel is separated from the edge of the second frequency band by a distance of less than R2 Hertz and the second channel is separated from the edge of the first frequency band by a distance of less than R1 Hertz, wherein R1 and R2 are determined in response to front end filter characteristics of the first and second RF transceivers.

A method of operating a wireless communication device is provided that includes a first Radio Frequency (RF) transceiver configured to transmit/receive RF signals in a first frequency band, a second RF transceiver configured to transmit/receive RF signals in a second frequency band different from the first frequency band, and a connection manager coupled to the first RF transceiver and the second RF transceiver. The method comprises the following steps: analyzing the RF channels allocated to the first and second RF transceivers to characterize the degree of mutual interference between the first and second RF transceivers; and rejecting the allocated channel in response to a degree of mutual interference between the first and second RF transceivers.

The method may further comprise the steps of: transmitting first channel allocation information from the first RF transceiver to the connection manager instructing the first RF transceiver to transmit and/or receive a first channel of RF communication signals; transmitting second channel allocation information from the first RF transceiver to the connection manager instructing the second RF transceiver to transmit and/or receive a second channel of RF communication signals; and analyzing the first channel allocation information and the second channel allocation information to determine whether potential mutual interference may exist between RF communication signals transmitted/received on the first channel and RF communication signals transmitted/received on the second channel.

The method may further comprise the steps of: in response to determining that there may be potential mutual interference between the RF communication signals transmitted/received on the first channel and the RF communication signals transmitted/received on the second channel, a channel reselection signal is transmitted to the first RF transceiver and/or the second RF transceiver instructing it to select a different channel to transmit/receive RF communication signals.

The method may further comprise the steps of: in response to receiving the channel reselection signal, transmitting a channel adjustment request from the first RF transceiver and/or the second RF transceiver to a remote network access point requesting allocation of a new channel to transmit/receive RF communication signals.

The channel adjustment request includes a Channel Quality Indicator (CQI) indicating that the allocated channel quality is not good.

The first RF transceiver may transmit/receive RF signals in the first frequency band according to a first wireless communication protocol, and the second RF transceiver may transmit/receive RF signals in the second frequency band according to a second wireless communication protocol different from the first wireless communication protocol.

The first RF transceiver may comprise a bluetooth transceiver, the method further comprising: selecting a frequency hopping carrier that does not collide with a frequency used by the second RF transceiver.

The method may further comprise the steps of: determining that there may be potential mutual interference between the first channel and the second channel in response to edges of the first channel and the second channel being separated by a distance less than R Hertz, where R may be equal to a width of a 30dB roll-off point of a band filter in the first RF transceiver or the second RF transceiver.

The method may further comprise the steps of: the connection manager determines that there may be potential mutual interference between the first channel and the second channel if the first channel and an edge of the second frequency band may be separated by a distance less than R Hertz, where R is equal to a width of a 30dB roll-off point of a band filter in the first RF transceiver or the second RF transceiver.

The connection manager may be configured to: determining that there may be potential mutual interference between the first channel and the second channel in response to the first channel being separated from an edge of the second frequency band by a distance less than R2 Hertz and the second channel being separated from an edge of the first frequency band by a distance less than R1 Hertz, wherein R1 may be equal to a width of a 30dB roll-off point of a band filter in the first RF transceiver, and wherein R2 is equal to a width of a 30dB roll-off point of a band filter in the second RF transceiver.

Other systems, methods, and/or computer program products according to embodiments of the invention will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, and/or computer program products be included within this description, be within the scope of the present invention, and be protected by the accompanying claims.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate some embodiments of the invention. In the drawings:

fig. 1 is a schematic depiction of a wireless communication terminal according to some embodiments.

Fig. 2 depicts wireless communication of a wireless communication terminal over multiple wireless communication interfaces, according to some embodiments.

Fig. 3 depicts a band arrangement around 2.4 GHz.

Fig. 4 depicts channel reallocation in a frequency band around 2.4GHz in accordance with some embodiments.

Fig. 5 depicts frequency domain scheduling in a Long Term Evolution (LTE) system employing orthogonal frequency division multiplexing, in accordance with some embodiments.

Fig. 6 depicts a link management protocol message sequence for paired bluetooth devices that sets adaptive frequency hopping.

Fig. 7 is a flow chart describing the operation of a channel selection system/method according to some embodiments.

Figure 8 depicts the bandpass filter roll-off characteristics.

Fig. 9 is a flow diagram of the operation of a channel selection system/method according to some embodiments.

Detailed Description

Embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.

Although the terms first, second, etc. may be used herein to describe various elements, it should be understood that these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

As used herein, a "wireless communication device" includes, but is not limited to, a device configured to receive/transmit communication signals over a wireless communication interface with, for example, a cellular network, a Wireless Local Area Network (WLAN), a digital television network such as a DVB-H network, a satellite network, an AM/FM broadcast transmitter, and/or another communication terminal. A wireless communication device may be referred to as a "wireless communication terminal," a "wireless terminal," and/or a "mobile terminal. Examples of wireless communication devices include, but are not limited to, satellite or cellular radiotelephones, Personal Communication Systems (PCS) terminals that may incorporate a cellular radiotelephone with data processing, facsimile and data communication capabilities, PDAs including radiotelephones, pagers, internet/intranet access, web browsers, organizers, calendars and/or Global Positioning System (GPS) receivers; as well as conventional laptop and/or palmtop computers or other applications that include radio transceivers, including WLAN routers and the like.

Wireless communication between electronic devices may be accomplished using a wide variety of communication media, communication systems, and communication standards. For example, wireless communication devices, such as wireless mobile telephones, are typically arranged to communicate via analog and/or digital wireless Radio Frequency (RF) telephone systems. Such devices are additionally configured to communicate using wired and/or wireless Local Area Networks (LANs), short-range communication channels, such as Bluetooth RF communication channels and/or infrared communication channels, and/or long-range communication systems, such as satellite communication systems.

According to some embodiments, a wireless communication device includes multiple RF communication modules that communicate with remote terminals (e.g., other communication devices, base stations, access points, etc.) using RF signals transmitted and/or received over dedicated or shared antennas in the wireless communication device. Each RF communication module is configured to operate within a defined frequency band. In particular, each RF communication module may communicate with a remote terminal using a channel selected from a plurality of channels within a frequency band.

Channel selection, also known as channel assignment or channel assignment, refers to the selection and assignment of RF channels in a wireless communication system. In a typical RF communication system, such as a cellular or PCS mobile communication system, channel selection is performed by a resource scheduler in the radio access network of the communication system, rather than by individual wireless communication devices in the system. Channel selection may be performed for the following purposes: the RF spectrum is efficiently configured to maximize data bandwidth and/or reduce co-channel interference between devices within the system, reduce average power consumption of wireless communication devices within the system, reduce average bit error rate for communication, and/or other goals.

The channel assignment/allocation scheme may be classified as either a fixed channel allocation or a dynamic channel allocation. In a dynamic channel allocation scheme, channels may be reallocated in response to changes in the communication system and/or RF communication environment. In a cellular communication system, such channel reallocation is performed under control and guidance of a resource scheduler in a node of a radio access network, which may monitor factors such as channel usage, channel requirements, co-channel and adjacent channel interference levels, among other factors. When the scheduler determines that a wireless communication terminal in the system needs to switch to a new channel for transmission/reception, the scheduler may send a control channel message to the wireless communication terminal instructing it to tune its transmitter/receiver to the new channel for transmission/reception.

However, the communication system may not be aware of other RF communication modules that are co-located in the wireless communication device and that may operate at frequencies near those used by the RF communication system. Such other RF communication module transmissions/receptions may cause co-channel and/or adjacent channel interference with RF communication modules in the wireless communication device that may not be detected/detectable by the communication system.

In order to cope with the presence of different RF transceivers in the same device, many different solutions have been considered. For example, it has been proposed to use different antennas with a large separation between them. Providing multiple, isolated antennas in a wireless communication device may result in less antenna-to-antenna interaction and less interference between signals transmitted/received by RF transceivers in the device. However, this requires sufficient spacing between the antennas and/or the directivity of the antennas. Separation between antennas is increasingly difficult because mobile devices shrink in size and directivity may be impractical for some wireless communication devices, such as mobile phones, unless expensive and powerful adaptive beamforming techniques are used.

It has also been proposed in the prior art to apply time division duplexing to communications by various RF transceivers in a device so that only one RF transceiver is activated at a time, or the RF transceivers all transmit or all receive at the same time. However, such approaches may be difficult to implement because they require coordination between RF transceivers operating according to different standards and/or effectively limit the throughput of the radio.

Spectrum is a scarce resource and regulatory agencies and the telecommunications industry are constantly looking for more available spectrum to meet the growing demand for capacity. Very high frequencies (above 5 GHz) are not suitable for long distance applications due to higher propagation attenuation, and very low frequencies (below 500 mhz) are not suitable for small devices due to reduced efficiency of small antennas, so hot spots have been focused on the available spectrum between about 800 mhz and 4 GHz. As a result, the separation between the frequency bands is reduced. Filters with steeper roll-off characteristics may help solve the problem of mutual interference. However, for filters operating at 2GHz, even the steepest filters require at least 1% of the guard band, which results in a 15-20 mhz guard band. A smaller guard band may require a steeper filter, which may increase cost, size, and/or more insertion loss, which may result in a less sensitive (and thus reduced range) wireless receiver. However, a20 MHz guard band may not be desirable due to the growing demand for more capacity.

Applying a TDD solution may require tight interaction of Medium Access Control (MAC) protocols between different radios. Packet scheduling (time-domain scheduling) of different radios may be required to avoid a situation where one radio transmits and the remaining one receives. Packet radio based radio protocols, Time Division Multiple Access (TDMA), and/or Time Division Duplex (TDD) allow a coarse time scheduling integration but do not significantly impact the specification. However, continuously operating radios, such as Frequency Division Duplex (FDD) and/or Code Division Multiple Access (CDMA), are excluded from the coexistence scheme because they are continuously active on both the uplink and downlink.

Some embodiments coordinate channel selection for two or more RF transceivers within a wireless communication device. In particular, a wireless communication device according to some embodiments facilitates channel selection within a wireless frequency band used by different RF transceivers in the device. If the co-location problem arises because the channels used by the different RF transceivers are spaced too closely in the frequency domain, the wireless communication device may suggest one or more available transceivers and/or networks associated with them, e.g., cellular networks, WiFi networks, and/or peer-to-peer bluetooth devices, to reassign the channels so that there is more spacing between the wireless channels and thus less interaction between the RF transceivers.

According to some embodiments, intelligent frequency scheduling is performed for multiple RF transceivers within the same wireless communication device. Intelligent frequency scheduling may enable the wireless communication device to assist the system in finding sufficiently spaced channels within the assigned radio frequency band. Scheduling assistance may only be needed when multiple RF transceivers within a wireless communication device are operating simultaneously.

A wireless communication device 100 according to some embodiments is shown in fig. 1.

In particular, the wireless communication device 100 is configured to transmit and/or receive wireless signals over one or more wireless communication interfaces. For example, the wireless communication device 100 according to some embodiments may include a cellular communication transceiver, a bluetooth transceiver, an infrared communication transceiver, a Global Positioning System (GPS) receiver, a WLAN transceiver, and/or other types of communication modules.

Through a cellular communication transceiver, the wireless communication device 100 may communicate using one or more cellular communication protocols, such as Advanced Mobile Phone Service (AMPS), ANSI-136, global standard for mobile communications (GSM), General Packet Radio Service (GPRS), enhanced data rates for GSM evolution (EDGE), Code Division Multiple Access (CDMA), wideband CDMA, CDMA2000, Universal Mobile Telecommunications System (UMTS), and Long Term Evolution (LTE).

The wireless communication device 100 may communicate over an ad-hoc network using a direct wireless interface via a bluetooth or infrared transceiver. Through the WLAN transceiver, the wireless communication device 100 may communicate through a WLAN router using communication protocols including, but not limited to, 802.11a, 802.11b, 802.11e, 802.11g, and/or 802.11 i.

The wireless communication device 100 may additionally include an AM/FM radio tuner, a UHF/VHF tuner, a satellite radio tuner, a DVB-H receiver, and/or another receiver configured to receive broadcast audio/video signals and/or data signals.

The wireless communication apparatus 100 includes: a display 108, such as a Liquid Crystal Display (LCD) and/or an Organic Light Emitting Diode (OLED) display. The wireless communication device 100 optionally includes a keypad 102 or other user input mechanism on the front housing 110 of the device 100. In some embodiments, the display 108 may be provided with touch screen functionality to replace and/or supplement the keypad 102.

The wireless communication device 100 may include a microphone 106 and an earpiece/speaker 104. The housing of the device 100 may be designed to form an acoustic seal against the user's ear when the earphone/speaker 104 is placed on the user's head.

The keypad 102, display 108, microphone 106, speaker 104, and camera 124 may be coupled to a processor 127, such as a microprocessor or microcontroller, configured to control the operation of the device 100.

The device 100 may further include a plurality of transceivers 140A-140D, including, for example, an LTE transceiver 140A, WiFi transceiver 140B, a cellular/PCS transceiver 140C, and/or a bluetooth transceiver 140D. As noted above, additional or fewer RF transceivers may be included in device 100.

The device 100 further includes a connection manager 170 coupled to the RF transceivers 140A-140D and the processor 127. The connection manager 170 may be implemented using, for example, a general purpose programmable microprocessor and/or a dedicated controller. Although described as separate components, the connection manager 170 may be implemented as a module within the processor 127 in some embodiments. The connection manager communicates with the RF transceivers 140A-140D to control/assist channel selection for transmission/reception by the RF transceivers 140A-140D to reduce mutual interference therebetween.

The mobile device 100 also includes a memory 128 coupled to the processor 127. Other electronic circuitry, such as a GPS interface, digital signal processor, etc., may also be included in the electronic circuitry of the device 100.

Transceivers 140A-140D typically include transmit circuitry, receive circuitry, and a modem to coordinate to transmit and receive radio frequency signals to and from remote transceivers via antenna 150. RF transceivers 140A through 140D communicate with antenna 150 through duplexer 160. Antenna 150 may include one or more radiating elements. The radio frequency signals transmitted between the device 100 and the remote transceivers may include both traffic and control signals (e.g., paging signals/messages for incoming calls), which are used to establish and maintain communication with another party or destination.

Memory 128 may be a general purpose memory for storing program instructions for processor 127 as well as data, such as audio data, video data, configuration data, and/or other data that may be accessed and/or used by processor 127. The memory 128 may include non-volatile read/write memory, read-only memory, and/or volatile read/write memory. In particular, memory 128 may include a read-only memory that stores basic operating system instructions, a non-volatile read/write memory that stores reusable data, such as configuration information, directory information, and other information, and a volatile read/write memory that may store short-term instructions and/or temporary data.

Fig. 2 illustrates a system environment in which a wireless communication device 100 may operate, according to some embodiments. As shown therein, wireless communication device 100 according to some embodiments may communicate with wireless access point 200 in a WIFI communication system over wireless communication link 75 established between WIFI transceiver 140B and access point 200 in communication device 100. The wireless communication device 100 can also communicate with an eNodeB base station 300 of the LTE communication system over a communication link 70 established by the LTE transceiver 140A in the wireless communication device 100.

The wireless communication device 100 may further communicate with a cellular/PCS base station 350 via a wireless communication link 80 and/or with a bluetooth enabled device 250 via a wireless bluetooth communication link 85.

As an example of mobile supplemental channel assignment according to some embodiments, consider the 2.4GHz ISM band and UMTS band 7 and UMTS band 40 above and below the ISM band, respectively. The 2.4GHz ISM band is defined as from 2400MHz to 2483.5 MHz. UMTS band 7 is defined as from 2500MHz to 2690MHz and UMTS band 40 is defined as from 2300MHz to 2400 MHz. Thus, there is no separation between the UMTS band 40 and the 2.4GHz ISM band, and the separation between the UMTS band 7 and the 2.4GHz ISM band is only 16.5 MHz.

This is depicted in fig. 3. In addition, the assignment of RX (receive) and TX (transmit) operating in the frequency band is also shown in fig. 3. The UMTS band 40 is an unpaired TD-LTE (Long Term Evolution) band to which Time Division Duplex (TDD) is applied. The ISM band is also an unpaired band to which TDD is applied. UMTS band 7 is a paired band. The lower frequency range of UMTS band 7 is assigned to the uplink (corresponding to transmission/TX of the communication terminal within this band) and the higher frequency range is assigned to the downlink (corresponding to reception/RX of the communication terminal).

Fig. 3 also shows exemplary

band filter characteristics

50A, 50B and 50C of filters applied to the signals (dashed lines) of TX/RX in UMTS band 40, ISM band and UMTS band 7, respectively. The passband of the band filter is assumed to cover the entire relevant band and rejection of approximately 30dB occurs at 20MHz from the band edge.

As a first example, as shown in fig. 4, assume that WiFi transceiver 140B operates on channel 61B in the lower portion of the ISM band and Long Term Evolution (LTE) transceiver 140A operates on channel 61A in the upper portion of band 40. Initially, the selected frequency channels may include 10MHz channels 61A for LTE in band 40 and 22MHz channels 61B for WiFi in the ISM band, located as shown in fig. 4. Due to the proximity of the channels being used, filtering may not be sufficient to reduce mutual interference between the signals. Due to the limited linearity of the RX front end, blocking may result.

For WiFi transceiver 140B, it would be necessary to move the WiFi channel to a higher portion of the ISM band, for example, to channel 62B. To do so, the wireless communication device 100 may need to renegotiate with the wireless Access Point (AP)200 to reallocate the selected channel. Alternatively, the wireless communication device 100 may skew the channel quality report indicating bad reception (i.e., it may exaggerate the side with bad quality) and the access point 200 will move the channel to a higher frequency, as shown in fig. 4. In this example, the communication of WiFi transceiver 140B is moved from channel 61B to channel 62B.

While the WIFI specification identifies 14 overlapping channels (with 5MHz channel spacing), only three non-overlapping channels are used. The three channels are each 22MHz wide and spaced 25MHz apart from center to center, collectively covering substantially the entire 2.4GHz band. Typically, only channel numbers 1, 6 and 11 are used. Only the lower channels (channel numbers 1-3) may be susceptible to interference from co-located transceivers. Thus, if the wireless communication device requests a channel reallocation of a new channel from channel 1, the AP200 will select a different channel that is 25MHz or 50MHz higher in frequency.

For LTE channels, two methods may be used. LTE applies Orthogonal Frequency Division Multiple Access (OFDMA) with frequency domain scheduling. That is, the assignment of the OFDM subcarriers is based on the quality of the subcarriers. Periodically, Channel Quality Indicator (CQI) reports are fed back by the wireless communication device to the eNodeB base station 300 to report the band quality (pilot signals spread over the band are used to determine the overall quality) for feedback. CQI reporting by the wireless communication device 100 may be done so that the eNodeB base station 300 will schedule that particular mobile phone only in the lower part of the channel, as shown in fig. 5. In LTE, data is scheduled in resource blocks, each of which contains 14 OFDM symbols (1 millisecond) and 12 subcarriers (180 kilohertz). Fig. 5 shows how resource blocks are reassigned from the upper portion to the lower portion of the RF channel. The CQI reports may indicate instantaneous channel quality in both the time and frequency domains.

The CQI reports only include quality reports for the resource blocks in use (pilot or reference symbols are scattered in the resource blocks sent in the downlink). In some embodiments, repeated unsuccessful assignment attempts will result in the eNodeB base station 300 changing the assignment based on the CQI reports, so that the eNodeB base station 300 will move the resource assignment away from the interfered area.

According to some embodiments, a message at the Radio Resource Control (RRC) layer, issued from the wireless communication device 100, is defined requesting the eNodeB base station 300 to allocate resource blocks in a specific part of the frequency band. This may reduce the time and/or resources consumed locating an available channel when responding to only CQI reports.

In still further embodiments, channel sounding may be used to identify available frequency bands. This is a commonly employed method in the uplink where the pilot/reference symbols are distributed throughout the band. The receiver may then determine which portions of the frequency band are available based on the quality of the reference symbols. Similar procedures may also be performed in the downlink. According to some embodiments, the sounding signal covering the entire frequency band is transmitted by the eNodeB base station 300 to the wireless communication device 100. The wireless communication device 100 may then report back a CQI covering the entire frequency band indicating poor quality resource blocks in a portion of the frequency band adjacent to the frequency band used by the co-located transceiver (or potentially to be used). Based on the above CQI reports, the eNodeB wireless communication terminal 100 knows the location of the unassigned resource blocks.

Alternatively, the CQI may indicate that the entire channel is bad. In this case, the eNodeB base station 300 may move the entire channel down in frequency, e.g., from channel 61A to channel 62A, as shown in fig. 4.

In another example, the bluetooth transceiver 140D may operate simultaneously with the LTE transceiver 140A in the frequency band 40. In this case, the carrier selection in the adaptive frequency hopping system of bluetooth may be that only the hopping carriers in the upper part of the ISM are selected. The bluetooth specification V4.0 supports this concept (i.e. selection of a frequency hopping carrier in AFH based on input from a host device such as a mobile phone).

In the above example, the WiFi radio channel may be placed higher in the ISM band to avoid interference with the radio operating in band 40. In a similar manner, a WiFi radio channel may be placed lower in the ISM band to avoid interaction with radios operating in band 7.

Bluetooth Adaptive Frequency Hopping (AFH) carrier assignment is defined, for example, in bluetooth specification release 4.0[ volume 2 ] section 4.1.4. As described therein, the primary device instructs the secondary device through the "LMP _ set _ AFH" message that only a subset of the available carriers may be used. The AFH Protocol Data Unit (PDU) as described in table 4.5 in the bluetooth specification defines an "LMP _ set _ AFH" message, which includes an AFH _ Instant field, an AAFH _ mode field, and an AFH _ Channel _ Map field.

The AFH _ Instant field refers to a future point in time when AFH starts at the master and slave. The AFH _ mode field indicates whether AFH is enabled or disabled. The AFH _ Channel _ Map field represents a subset of 79 frequency carriers indicating which carriers can be used for frequency hopping and which carriers are not available for frequency hopping.

According to some embodiments, the wireless communication device 100 can transmit the AFH PDU to the remote bluetooth device 250. In the AFH _ Channel _ Map field, the lower (in case of interference with band 40) or higher (in case of interference with band 7) frequency carriers may be blocked (i.e. not available for frequency hopping). The primary device sends a Link Management Protocol (LMP) message "LMP _ set _ AFH" to the secondary device to force it to use a subset of the available carriers. In embodiments where the wireless communication device 100 is a bluetooth master device, the wireless communication device 100 will establish its own channel map. If the wireless communication device 100 is a bluetooth slave device, the wireless communication device 100 may send an "LMP _ channel _ classification" message to the remote master device 250, where the message indicates which carriers are bad. Finally, the final channel mapping is set by the master. The master may require the secondary to send its carrier estimate via an "LMP _ channel _ classification _ req" message as shown in fig. 6.

The frequency hopping channel and frequency hopping sequence used to communicate these LMP messages are the channels currently in use. A future point in time set in the AFH instant field indicates when to use a new hopping channel. Any new LMP messages (including those used to change the carrier subset again) are transmitted on this new channel until the next AFH _ instant that may be defined.

In the GSM system, the channel assignment message is transmitted over a downlink control channel. When the connection is setup, this will be the Access Grant Channel (AGCH), which is part of the Common Control Channel (CCCH). The layer 3 "immediateeassignment" message includes an RF carrier assigned to the Mobile Station (MS). This message is sent from the Base Transceiver System (BTS) to the MS.

During the connection process, different carriers may be assigned by a layer 3 message "Assignment command", including the RF carrier to be assigned to the MS. The assignment message is sent by the BTS to the MS over a Slow Associated Control Channel (SACCH).

Mobile-assisted channel assignment according to some embodiments may be implemented in an LTE system as follows. In the LTE downlink, the first n OFDM symbols (n <4) are used for downlink control signaling. In these OFDM channels, an allocation message is sent to a User Equipment (UE) (corresponding to the wireless communication device 100) to indicate which resource blocks (sets of carriers + slots) are used for downlink and/or uplink communication.

According to some embodiments of the present invention, the channels used by different RF transceivers may be spaced far enough apart to enable filters in the transceivers to substantially reduce mutual interference between the transceivers. Since the wireless communication device knows which radios are in operation and which frequency bands are in use at a given time, the wireless communication device can indicate to the network its preferred RF channel. In some embodiments, the wireless communication device may take action if 1) multiple transceivers are operating simultaneously, and 2) the channels in use in the transceivers may interfere with each other due to being too close together. In some embodiments, a connection manager in a wireless communication device controls assistance with channel selection.

A transceiver in a wireless communication device, such as a small portable communication device, may be operated to avoid unwanted performance degradation and/or unnecessary cost, large front-end filters by allowing the network to use channels that are sufficiently separated in the frequency domain. Thus, systems/methods according to some embodiments may reduce the overall cost and/or size of a wireless communication device.

A system or method according to some embodiments is shown in more detail in fig. 7, fig. 7 being a flow chart of operations that a wireless communication device may perform according to some embodiments. Referring to fig. 7, a wireless communication device 100 (fig. 1) including a plurality of RF transceivers 140A through 140D receives a channel assignment from a network (e.g., from a base station 300 or a wireless access point 200) (block S10). The channel assignment identifies a channel that one of the transceivers 140A-140D in the wireless communication device 100 is authorized to use for uplink (transmission) and/or downlink (reception) communications.

In block S20, the wireless communication device 100 determines whether another one of the RF transceivers 140A through 140D in the device is currently operating. If another one of the RF transceivers 140A through 140D is currently operating, the wireless communication device 100 determines whether the assigned channel conflicts with any one of the channels currently used by the device 100 (block S30). That is, in some implementations, the wireless communication device 100 can determine that a frequency in the allocated channel is set less than a defined frequency distance from a band edge of a channel and/or frequency band that the wireless communication device has used. In some implementations, the defined frequency distance can be based on characteristics of one or more band filters in the wireless communication device 100. For example, the defined frequency distance may be a 30dB roll-off bandwidth, as described below.

For example, assume that a first RF transceiver is operating in device 100 and uses a first channel within a first frequency band. The bandpass filter for the first band has a 30dB roll-off point (i.e., the point at which the signal is attenuated by 30 dB) that is R hertz from the edge of the first band, which may be defined in some systems as the-3 dB roll-off point of the filter, as shown in fig. 8. The roll-off bandwidth in such a case may be R hertz. In general, it is desirable to operate a co-located transceiver on a frequency band where signals from adjacent frequency bands are suppressed by 30dB (reference band edge) or more.

It should be understood that each RF transceiver in the wireless communication device 100 may employ a bandpass filter having different roll-off characteristics. Thus, the roll-off bandwidth R of a band filter in one RF transceiver may be different from the roll-off bandwidth R of a band filter in another RF transceiver.

When the wireless communication device 100 receives a channel assignment for a second RF transceiver in the device 100 from an associated network, the wireless communication device checks to determine if the second RF transceiver assigned channel is within R hertz of the first channel, and if so, the wireless communication device can determine that the assigned channels are in conflict.

In some implementations, the wireless communication device may check to determine whether the first channel is within R hertz of the second frequency band and the second channel is within R hertz of the first frequency band (as shown in fig. 3), in which case the wireless communication device may determine that the assigned channels collide. It should be appreciated that the roll-off bandwidth R may be different for different channels, e.g., the roll-off bandwidth R of a first channel is different from the roll-off bandwidth R of a second channel. That is, the existence of collisions may be determined by determining a frequency spacing between the allocated channels and/or by determining a frequency spacing between the allocated channels and adjacent frequency bands.

If it is determined that the assigned channels conflict, the wireless communication device 100 may request, from the network associated therewith, a re-assignment of the conflicting single channel or both channels (block S40). Once the wireless communication device 100 receives the new channel assignment (block S50), operation returns to block S30 to determine whether the reallocated channels conflict. If it is determined in block S20 that no other radio is operating within the wireless communication device 100, or it is determined in block S30 that the channels do not collide, the allocated channel is used for communication (S60).

In some embodiments, the connection manager 170 may scan the frequency band and determine and identify idle channels to suggest to the base station or access point. Alternatively or additionally, the connection manager 170 may inform the network of an acceptable frequency range from which to select a new channel. The different radios 140A-140D in the wireless communication device 100, including their associated interference levels and filter characteristics, are known at design time. These data may be stored in a look-up table for use by the connection manager 170 when checking to determine if the channel assignments are too close together. Alternatively, the connection manager 170 may receive CQI reports from the radios 140A-140D themselves. With this information, the connection manager can request the network to reassign the channel.

Message flow in some embodiments according to the invention is illustrated in fig. 9, which shows information channel reselection performed by the LTE transceiver 140A and the connection manager 170 in the wireless communication device 100.

After registering with the LTE network, the LTE transceiver 140A receives a channel assignment 310 from the eNodeB base station 300. The LTE transceiver 140A sends channel allocation information 31 to the connection manager 170 indicating the channels/subcarriers that have been allocated to the LTE transceiver 140A. The connection manager 170 analyzes the assigned channels/subcarriers and determines whether the channel assignment conflicts or potentially conflicts with an existing channel assignment being used by another transceiver in the wireless communication device, due to insufficient spacing between the assigned channels, as discussed above.

In response to determining that a collision or potential collision exists, the connection manager 170 sends a channel reselection signal 314 to the LTE transceiver 140A, which in turn sends a Channel Quality Indicator (CQI)316 to the eNodeB base station 300 indicating that the allocated channel quality is poor. In some embodiments, the connection manager may send an explicit message other than a CQI report to the eNodeB base station 300 to inform which frequency to use or not. Thereafter, the eNodeB base station 300 may send the updated channel allocation 318 to the LTE transceiver 140A.

As will be appreciated by one skilled in the art, the present invention may be embodied as methods, data processing systems, and/or computer program products. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects all generally referred to herein as a "circuit" or "module". In addition, the present invention may take the form of a computer program product on a tangible computer-usable storage medium having computer program code embodied in the medium for execution by a computer. Any suitable tangible computer readable medium may be used including hard disks, CDROMs, optical storage devices, or magnetic storage devices.

Some embodiments of the present invention are described above with reference to flowchart illustrations and/or block diagrams of methods, systems and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks.

The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

It should be understood that the functions/acts noted in the blocks may occur out of the order noted in the operational illustrations. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Although some of the figures include arrows indicating a primary direction of communication over the communication paths, it is to be understood that communication may occur in the opposite direction to the depicted arrows.

Computer program code for carrying out operations of the present invention may be written in an object oriented programming language such as Java @, Smalltalk or C + +. However, the computer program code for carrying out operations of the present invention may also be written in conventional procedural programming languages, such as the "C" programming language. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer. In the latter scenario, the remote computer may be connected to the user's computer through a Local Area Network (LAN) or a Wide Area Network (WAN), or the connection may be made to an external computer (for example, through the Internet using a network service provider).

Many different embodiments are disclosed herein in connection with the above specification and the accompanying drawings. It should be understood that verbatim descriptions and illustrations of each and every combination and subcombination of these embodiments are intended to be overly repeated and obscure. Thus, all of the embodiments may be combined in any manner and/or combination, and this specification (including the drawings) should be considered to constitute a detailed written description of all combinations and subcombinations of the embodiments described herein, as well as the manner and process of making and using them, and should be supported by claims claiming any such combination or subcombination.

In the drawings and specification, there have been disclosed typical embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.

Claims

1. A method of operating a wireless communication device (100) comprising a first RF transceiver (140A-D) configured to transmit/receive radio frequency, RF, signals in a first frequency band of a cellular network operating according to a first radio access technology, and a second RF transceiver (140A-D) configured to transmit/receive RF signals in a second frequency band of a second radio access network operating according to a second radio access technology, different from the first frequency band, the method comprising the steps of:

determining, at the wireless communication device (100), one or more frequencies in the first frequency band that are affected by interference due to transmission of the second RF transceiver (140A-D) in the second frequency band;

characterized in that the method further comprises the steps of:

transmitting a message from the first RF transceiver (140A-D) to a cellular base station (300) of the cellular network, the message comprising the one or more frequencies affected by the interference, wherein the transmitted message further informs the cellular base station (300) which frequencies will or will not be used.

2. The method of claim 1, further comprising the steps of:

receiving an updated channel allocation from the cellular base station (300) based on the one or more frequencies affected by the interference.

3. The method of claim 2, wherein receiving the updated channel allocation comprises: an allocation message is received that includes a set of carriers and time slots for communication.

4. The method of any of claims 1 to 3, wherein the step of transmitting a message from the first RF transceiver (140A-D) to the cellular base station (300) comprises:

transmitting the message from the first RF transceiver (140A-D) to the cellular base station (300) in response to determining the one or more frequencies in the first frequency band.

5. The method of any of claims 1-3, wherein the interference due to transmissions by the second RF transceiver comprises co-channel interference.

6. The method of any of claims 1-3, wherein interference due to transmission of the second RF transceiver (140A-D) in the second frequency band is determined based on a first frequency channel associated with the first frequency band and a second channel associated with the second frequency band being separated by a distance of less than R Hertz,

wherein R is determined from front-end filter characteristics of the first and/or second RF transceivers (140A-D).

7. The method of any of claims 1-3, wherein interference due to transmission of the second RF transceiver (140A-D) in the second frequency band is determined based on edges of a first frequency channel associated with the first frequency band and a second channel associated with the second frequency band being separated by a distance of less than R Hertz, and

wherein R is equal to the width of the 30dB roll-off point of a band filter in the first RF transceiver (140A-D) and/or the second RF transceiver (140A-D).

8. The method of any of claims 1-3, wherein the step of determining one or more frequencies in the first frequency band that are affected by interference due to transmission of the second RF transceiver (140A-D) in the second frequency band comprises:

determining in the wireless communication device (100) whether a channel assignment being used by the first RF transceiver (140A-D) conflicts or potentially conflicts with an existing channel assignment being used by the second RF transceiver (140A-D).

9. A method of operating an eNodeB base station (300), the method comprising the steps of:

receiving, from a wireless communication device (100), a message comprising one or more frequencies of a first frequency band affected by interference due to transmissions in a second frequency band at the wireless communication device (100); and

transmitting a channel assignment to the wireless communication device (100) in response to receiving the message, wherein the received message further informs the eNodeB base station which frequencies will or will not be used.

10. The method of claim 9, wherein the channel assignment comprises a second channel assignment, the method further comprising:

transmitting a first channel assignment to the wireless communication device (100), wherein the first channel assignment is transmitted prior to receiving the message.

11. The method of claim 10, wherein the second channel allocation comprises an updated channel allocation based on the one or more frequencies affected by interference at the wireless communication device (100).

12. The method of claim 9 or 10, wherein the interference at the wireless communication device (100) comprises co-channel interference.

13. The method of claim 9 or 10, wherein the channel assignment is transmitted to the wireless communication device (100) in an assignment message comprising a set of carriers and time slots for communication.

14. The method of claim 9 or 10, wherein the interference at the wireless communication device (100) is associated with existing channel allocation conflicts or potentially conflicting channel allocations being used by a first RF transceiver (140A-D) and being used by a second RF transceiver (140A-D) in the wireless communication device (100).