Dynamic bandwidth switching for reducing power consumption in wireless communication devices.

BACKGROUND OF THE INVENTION

The demand for wireless data services continues to increase exponentially. As the demand for data increases, techniques capable of providing higher data rates remain of interest. One way to provide higher data rates is to increase the spectral bandwidth available for wireless communication systems.

Reflecting the trend of increasing bandwidth, current versions of the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) networks have up to 100 megahertz (MHz) available for communication. Furthermore, it is possible that future networks, such as fifth generation (or 5G) networks, may use several hundred MHz or more in an attempt to meet future demand for data services.

As system bandwidth increases, data transmission can increase approximately proportionally without incurring a similar proportional increase in control overhead. Therefore, in future time division multiplexing (TDM) systems that multiplex control and data channels, there may be scenarios in which it would be inefficient for the control channels to occupy as much bandwidth as the data channels. There are inefficiencies both because spectral resources can be used unnecessarily that could be better used for other purposes and because mobile devices would be tuned to a larger bandwidth than necessary, thus wasting energy resources. Therefore, there is a need to more efficiently multiplex control and data channels as available bandwidth increases in wireless communication systems.

BRIEF DESCRIPTION OF THE INVENTION

In one aspect of the disclosure, a wireless communication method includes transmitting a control signal to a mobile device using a first bandwidth, and transmitting a data signal to the mobile device using a second bandwidth, wider than the first bandwidth. , where the control signal and the data signal are transmitted on a single carrier frequency.

In a further aspect of the disclosure, a wireless method on a mobile device includes receiving a control signal that has a first bandwidth and receiving one that has a wider bandwidth than the first bandwidth, where control and data signal are received at a single carrier frequency.

In a further aspect of the disclosure, a wireless communications computer program product includes a non-transient computer readable medium that hides a program code registered therein, the program code including a code to cause it to transmit a signal using a first bandwidth. The program code further includes a code to cause the transmitter to emit a signal using a second bandwidth more than 1 bandwidth, where the control signal and the data signal are transmitted over a single carrier frequency. .

In a further aspect of the disclosure, a computer program product for wireless communications includes a non-transient computer readable medium having a program code registered therein, the program code including a code to cause a receiver to receive a control signal that has a first bandwidth. The program code further includes a code to cause the receiver to receive a data signal that has a second bandwidth wider than the first bandwidth, where the control signal and the data signal are received over a frequency. single carrier.

In a further aspect of the disclosure, a mobile device includes an adjustable radio frequency (RF) front end configured to receive a control signal that has a first bandwidth, and receive a data signal that has a second bandwidth width than the first bandwidth, where the control signal and the data signal are received on a single carrier frequency.

In a further aspect of the disclosure, a wireless communication apparatus includes an amplifier, an analog-to-digital converter (ADC), an analog filter coupled between the amplifier and the ADC, and a control processor coupled to the amplifier, the ADC. , and the analog filter. The control processor is configured to, in response to receiving control information from a control signal having a first bandwidth, set the bandwidth of the amplifier and the ADC to a second bandwidth wider than the first width. bandwidth, and set the ADC master rate according to the second bandwidth.

In a further aspect of the disclosure, a wireless communication apparatus includes a control processor configured to couple a front end RE, adjust the front end RE to receive a control signal having a first bandwidth, and adjust the front end RF to receive a data signal that has a second bandwidth wider than the first bandwidth, where the control signal and the data signal are received on a single carrier frequency.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 illustrates a wireless communication re, in accordance with various aspects of the present disclosure.

Figure 2 is a high level block diagram of an adjustable receiver according to various aspects of the present disclosure.

Figure 3 illustrates a frame format and the corresponding power consumption of an RF front end according to various aspects of the present disclosure.

Figure 4 is a flow chart illustrating an exemplary method for receiving control signals and data in accordance with various aspects of the present disclosure.

Figure 5 illustrates another frame format and corresponding power consumption of an RF front end during reception of the illustrated frame format in accordance with various aspects of the present disclosure.

FIG. 6 is a flow chart illustrating another exemplary method for receiving control signals and data in accordance with various aspects of the present disclosure.

Figure 7 illustrates an example of the frame and signal structure for a frequency division multiplexing (FDM) system in accordance with various aspects of the present disclosure.

FIG. 8 is a protocol diagram illustrating transmissions between a base station and a UE for an FDM system in accordance with various aspects of the present disclosure.

Figure 9 is a protocol diagram illustrating signaling aspects between a UE and a base station to support dynamic bandwidth switching in accordance with various aspects of the present disclosure.

FIG. 10 is a block diagram of a transceiver in accordance with various aspects of the present disclosure.

Figures 11-16 illustrate additional embodiments of a frame format in accordance with various aspects of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

The detailed description below, in connection with the accompanying drawings, is intended to be a description of various configurations and is not intended to represent the only configurations in which the concepts described herein can be practiced. The detailed description includes specific details for the purpose of providing a complete understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some cases, well-known structures and components are shown in block diagram form to avoid obscuring such concepts.

The techniques described here can be used for various wireless communication networks such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA and other networks. The terms network and system are frequently used interchangeably. A CDMA network can implement a radio technology such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes Broadband CDMA (WCDMA) and other CDMA variants. cdma2000 covers IS-2000, IS-95 and IS-856 standards. A TDMA network can implement a radio technology such as the Global System for Mobile Communications (GSM). An OFDMA network can implement radio technology such as Evolved UTP.A (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE

802.20, Flash-OFDMA, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunication System (UMTS). Evolution to

Long Term 3GPP (LTE) and LTE-Advanced (LTE-A) are new versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described in documents from an organization called the 3rd Generation Partnership Project (3GPP). CDMA2000 and UMB are described in documents from an organization called 3rd Generation Partnership Project 2 (3GPP2). The techniques described here can be used for the aforementioned wireless networks and radio technologies as well as other wireless networks and radio technologies, such as a next generation network (eg 5th Generation (5G)}.

This disclosure recognizes that as the available system bandwidth increases, the bandwidth used by data signals can be increased (and thus the data rate can be increased) without corresponding increases in. control channel signaling. Frame formats are disclosed using narrowband control signals and wideband control signals. Frame formats allow adjustments to be made at mobile device receivers to receive control signals over a wide bandwidth and data signals over wider bandwidths. A receiver can use a low power mode to receive a control signal and then can increase the bandwidth and power consumption to receive a data signal. An interval or transition period can be inserted between a control signal and a data signal to give the receiver time to adjust to different signal bandwidths.

The power consumption of a wireless communication receiver scales with the received signal bandwidth. This disclosure generally relates to wireless communication networks that employ control signals and data signals of different bandwidths. Receivers in such networks are provided to take advantage of and adjust to different bandwidths to reduce power consumption. For example, the power consumption in wireless devices can be reduced because control signals can occupy a bandwidth

0 smaller than in conventional systems.

FIG. 1 illustrates a wireless communication network 100, in accordance with various aspects of the disclosure. Wireless communication network 100 can be an LTE network or a next generation network (eg 5G). Wireless network 100 can include a number of base stations

110. A base station 110 may include an improved Node B in the LTE context. A base station may also be referred to as a base transceiver station or an access point.

Base stations 110 communicate with user equipment (UEs) 120 as shown. A UE 120 can communicate with a base station 110 through an uplink and a downlink. The downlink (or forward link) refers to the communication link from a base station 110 to a UE 120. The uplink (or reverse link) refers to the communication link from a UE 120 to a base station 110.

The UEs 120 can be scattered through the wireless network 100, and each UE 120 can be stationary or mobile. A UE can also be referred to as a terminal, a mobile station, a subscriber station, etc. A UE 120 can be a cell phone, smartphone, personal digital assistant, wireless modem, laptop computer, tablet computer, etc. Wireless communication network 100 is an example of a network to which various aspects of the disclosure can be applied. Other examples are WLANs.

Fig. 2 is a high level block diagram of an adjustable receiver 200. Adjustable receiver 200 can be included in a UE 120. Adjustable receiver 200 can include one or more antennas 210. If adjustable receiver 200 includes multiple antennas 210 , any technique can be used for multiple-input multiple-output (MIMO) communication. For convenience, the description will focus on an antenna 210a and its associated components with the understanding that the description applies to each antenna and its associated components.

In this example, the adjustable receiver 200 includes a front end RE 212a. In this example, the RF front end 212a includes an amplifier 215a, a mixer 220a, an analog filter 225a, and an analog-to-digital converter (ADC) 230a in communication with antenna 210a as shown. Adjustable receiver 200 employs a zero intermediate frequency (IF) architecture in which a signal received at antenna 210a is amplified by amplifier 215a and then directly downconverted to baseband by mixer 220a in conjunction with the local oscillator (LO) 240. A radio frequency (RF) amplifier, such as the low noise amplifier (LNA), is an example of amplifier 215a.

Analog filter 225a can be a low-pass filter with adjustable bandwidth. The received signal is typically a sum of a signal carrying desired data, interference, and noise. In some scenarios, the bandwidth of the analog filter 225a is configured to avoid overlap, allow the desired signal to pass with relatively little distortion to the ADC 230a, and attenuate out-of-band interference and noise.

The ADC 2 30a receives an analog signal at its input and displays and digitizes the analog signal to produce a digital output. The ADC 230a sampling rate is sufficient to avoid or sufficiently limit signal overlap and is generally at least twice the highest frequency component of the input signal. The sampling rate of the · ADC 230a can be adjustable to suit the desired sampling rate according to signals with different input bandwidths.

The adjustable receiver 250 further includes a baseband processor 245. The baseband processor 245 receives the signals from all receive chains and performs demodulation and decoding (if necessary) of the received signals.

The adjustable receiver further includes a control processor 255. Control processor 255 can direct the operation of adjustable receiver 200. Control processor 255 generates one or more command signals (represented by dashed lines) intended for amplifiers 215, analog filters 225, ADCs 230, and / or the baseband processor 245. Command signals may also be referred to herein as internal control signals to distinguish the nomenclature of uplink and downlink control signals transmitted over wireless channels.

The adjustable receiver 200 further includes a memory 250. The memory. 250 can be any electronic component with the ability to store information and / or instructions. For example, memory 250 may include random access memory (RAM), read-only memory (ROM), flash memory devices in RAM, optical storage media, erasable programmable read-only memory (EPROM), registers, or combinations thereof. In one embodiment, memory 250 includes a non-transient computer readable medium.

Instructions or code can be stored in memory 250 which are executable by baseband processor 245 and / or control processor 255. The terms instructions and code should be broadly interpreted to include any type of computer readable statement. For example, the terms instructions and code may refer to one or more programs, routines, sub-routines, functions, procedures, etc. Instructions and code can include a single computer-readable statement or many computer-readable statements.

Control processor 255 can be implemented using a general-purpose processor, digital signal processor (DSP), application specific integrated circuit (ASIC), field programmable gate array (FPGA), or other programmable logic device, discrete or transistor logic gate, discrete hardware components, or any combination thereof designed to perform the functions described here. Control processor 255 can also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a core DSP, or any other configuration of this type.

Amplifiers 215, analog filters 225, and / or ADCs 230 can be components with adjustable parameters so that adjustable receiver 200 can be adapted to receive signals of different bandwidths in a way that power consumption varies according to bandwidth. Power consumption generally decreases with decreasing bandwidth. For example, amplifiers 215 and analog filters 225 may have 'bandwidths that are adjustable, with the bandwidths set according to the corresponding command signals. Additionally, ADCs can have an adjustable sample rate, with the sample rates set according to the corresponding command signal.

Consider an exemplary scenario in the. which adjustable receiver 200 waits for a relatively narrow band signal followed by a relatively wide band signal. Before receiving the narrowband signal, control processor 255 can set the bandwidths of amplifiers 215 and analog filters 225 accordingly, and can set the sampling rate of ADCs 230 accordingly. After receiving the narrowband signal but before receiving the broadband signal, control processor 255 can increase the bandwidths of amplifiers 215 and analog filters 225 to accommodate the widest bandwidth, and can increase speed ADCs sampling to also accommodate the widest bandwidth. The greater the signal bandwidth, the greater the power required to process the signal.

The zero IF architecture of Figure 2 is understood to be one of many receiver architectures that can be tuned to receive signals of various bandwidths. Many different receiver architectures, in accordance with the present disclosure, can employ amplifiers, filters, and ADCs in various combinations whose parameters can be adjusted.

This disclosure is directed to any type of modulation scheme, but orthogonal frequency division multiplexing (OFDM) is used as a representative modulation. OFDM is a flexible modulation scheme that allows adjusting the bandwidth of the transmitted signal in a direct way.

OFDM modulation uses a number of subcarriers, the separation between subcarriers can be fixed, and the total number of used subcarriers can be modified depending on the signal bandwidth. For example, the separation between subcarriers can be 4 kHz and the number of subcarriers can be 100, in which case the signal bandwidth is approximately 400 kHz (number of subcarriers multiplied by the separation between subcarriers), not counting the bands of protection. Therefore, one way to scale bandwidth using OFDM is to scale the number of subcarriers. There are other well known ways to scale OFDM signal bandwidth, such as scaling the frequency spacing between subcarriers. OFDM is demodulated using a fast Fourier transform (FFT), and the size of the FFT can be modified according to the number of subcarriers. Therefore, the. Baseband processor 245 may include at least one antenna adjustable FFT to adapt demodulation to different signal bandwidths. Control processor 255 can control baseband processor 245 to indicate the size of the FFT or other parameters to adapt baseband processor 245 to OFDM signals with parameters that vary according to bandwidth. After an OFDM signal is formed, it can be transmitted using a separate single high-frequency carrier, sometimes referred to as an RF carrier. The available time-frequency resources can be divided into resource blocks. Each resource block can cover N subcarriers (eg 12 subcarriers) in an OFDM symbol modulation.

The operation of the adjustable receiver 200 is further described with reference to FIG. 3. FIG. 3 illustrates a frame format 310 and the corresponding power consumption 360 of an example of front end RF, such as front end RF 212a, during receiving the illustrated frame format. Frame format 310 is a TDM format in which the time is divided into transmission time slots (TTIs). Control signals and data signals are time division multiplexed within a TTI. Figure 3 illustrates an example of the sequence of signals transmitted within this frame format 310.

A TTI can refer to the duration of a transmission on the radio link. A TTI may be related to the size of the data blocks passed from the upper network layers to the radio link layer. In some embodiments, the duration of the data symbols, such as OFDM symbols, is fixed and there is a predetermined number of data symbol periods during each TTI. For example, each TTI can be any number of symbol periods, such as 8, 10, or 12 symbol periods, as examples.

In wireless communication systems, a downlink control signal may include information for a UE related to establishing, maintaining, or terminating a data session. For example, a downlink control signal in a TTI may provide information to a UE as to whether a downlink data signal is still in the TTI, and if so, the control signal may indicate a width of signal band.

of data.

Trainee 310 format is designed for the purpose of reducing power consumption in UE receivers. A control signal 315 is transmitted at the beginning of each TTI.

The control signal uses a relatively narrow bandwidth compared to the data signals. The control signal bandwidth is sufficient to transmit control information to the intended UEs, and it is not necessary to use the larger bandwidths used for data signals for the relatively small amount of control information. In a TTI, the control signal indicates whether there is a data signal following the control signal. In some embodiments, the bandwidth used for data signals is variable, in which case the control signal also indicates the bandwidth used for the following data signal. Alternatively, in some embodiments, the data signals always occupy a certain bandwidth (such as the entire bandwidth), in which case the bandwidth of the data signal is understood or unspoken and there is no need for the control signal transmit bandwidth information.

Each of the transmitted signals is transmitted using a single carrier frequency f_c. Using a

0 single carrier simplifies receivers compared to systems that use carrier aggregation. Carrier aggregation typically requires the use of multiple LOs, while the signaling schemes described here can use only one LO. However, the approaches described in the present disclosure can also be applied at multiple carrier frequencies.

The frame formats disclosed here, such as frame format 310, may apply without regard to the number of antennas used at the transmitting or receiving entity. For example, in a SISO system, the signal is transmitted from the transmitting antenna and received at the receiving antenna. As another example, in a MIMO system, the illustrated frame formats are transmitted from at least one antenna. Each antenna among a plurality of antennas can transmit the same pilot structure or a different pilot structure. In one embodiment, the illustrated frame format 310 will be received by a receiving antenna, and may be part of a composite signal that is a sum of signals from a plurality of antennas.

In this example, in the n “^vo TTI (TTI_rJ, control signal 315 indicates to the designated UE that no data remains in the TTI. The adjustable receiver 200 can be used to receive the 315 control signal. After the adjustable receiver 200 receives the 315 control signal in the TTI_n, RF front end components 215, 225, and 230 can be temporarily turned off or closed by control processor 255, placing the adjustable receiver 200 in a microsleep state. For example, a switch can be placed between a component, such as an amplifier 215, an analog filter 225, and / or an ADC 230, and its power supply, with the switch being opened for a period of time to turn off power. to the component. Another example of microsleep is placing a component in an idle state in which it receives a reduced amount of power to operate in a reduced capacity.

The RF 360 power consumption of an RF front end, such as the. RF front end 212a on the adjustable receiver 200, illustrated in Figure 3 during reception of various signals. For example, during reception of the control signal 315 in the TTI_n, the power consumption is represented by 365. After determining that there is no data, the adjustable receiver 200 transitions to a microsleep state, and the power consumption during that transition is represented by 370. The decrease in power consumption Power is represented as a linear decrease over time, but the actual decrease in power consumption may be non-linear but may be decreasing over time however. During the interval in TTI_n after being placed in microsleep, RF power consumption is much less than when a signal is being received because amplifiers 215, analog filters 225, and ADCs 230 have been turned off.

Shortly before TTI_n+ i, control processor 255 informs amplifiers 215, analog filters 225, and ADCs 230 to turn on before receiving control signal 315 during TTI_n.₍₁. The power consumption during that transition is represented by 375, and the power consumption during reception of the 315 control signal in TTI_{n +}i is represented by 380. Components in receiver 200 that have been turned off need a period of time to turn on long enough to receive a signal.

In this example, control signal 315 is followed by data signal 325 at en_η!χ. Baseband processor 245 demodulates control signal 315 and provides the control signal information to the control processor. 255. The information in control signal 315 indicates to control processor 255 that a data signal will follow. In some scenarios, data signal 325 is a wider bandwidth than control signal 315. In response, control processor 255 informs amplifiers 215, analog filters 225, and ADCs 230 to adjust appropriately for the widest bandwidth. That is, the bandwidths of amplifiers 215 and analog filters 225 are increased, and the sampling rate of ADCs 230 is also increased. In some embodiments, control processor 255 also informs baseband processor 245 to adapt accordingly to increased bandwidth. For example, for demodulation of OFDM signals, control processor 255 informs baseband processor 245 to adjust the size of the FFT or other parameters appropriately in order to demodulate the incoming data signal.

Frame format 310 may further provide frequency division multiplexing (FDM) between users.

For example, bandwidth B data signal 325 may be divided into the frequency domain with different portions of bandwidth B assigned to different users. The RF 212 front end for a user can continue to be adjusted appropriately for bandwidth B with extraction and demodulation of the desired portion that is digitally executed in the frequency domain using OFDM techniques.

In one embodiment, the control signal 315 indicates not only that the data will follow but also indicates the bandwidth of the data signal 325. In this case, the

<img file="MX368489B_D0001.tif" />

4 Control processor 255 determines the bandwidth. In other modes, data signal 325 always occupies the

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data signals, the components of the adjustable receiver 200 are tuned from data signal to data signal to receive using only enough bandwidth to cover the bandwidth of the data signal of interest, rather than always tuning to receive using all available system bandwidth.

There is a transition period 320 between control channel 315 and data signal 325 to allow adjustable receiver 200 to adjust to the different bandwidth. Transition period 320 can be referred to as a switching interval because receiver 200 is switching from one bandwidth to another. The switching interval can be quantized to an integer number of symbol periods, such as OFDM symbol periods. The power consumption during this transition period 320 is represented by 385, and the power consumption during reception of the data signal 325 is represented by 390.

There is a transition period 330 between data signal 325 and the following control signal 315 in the TTI_{n + 2}. Transition period 330 gives adjustable receiver 200 time to transition to a smaller bandwidth for control signal 315. Power consumed during transition period 330 is represented by 395.

Some conventional TDM systems typically do not include transition periods 320 and 330 to allow a receiver to make the adjustment. One reason is that in some conventional TDM systems the control signal is transmitted using the same bandwidth as the data signal so that receivers do not need to transition between different bandwidths. Therefore, the power consumed during transition periods 320 and 330 represents a power penalty for the signaling scheme in Figure 3 compared to some conventional systems. However, there are substantial power savings during reception of control signal 315 in the frame format illustrated in Figure 3. The. Power saving includes the difference in power between the RE power consumed during reception of the data signal and the RE power consumed during reception of the control signal. The corresponding energy savings are calculated as an area under the

6 power. Under some conditions, the total power savings exceed the power penalty, in which case the frame format and corresponding adjustable receiver 200 extend battery life compared to conventional TDM systems.

FIG. 4 is a flow chart illustrating an exemplary method 400 for receiving control signals and data. Method 40C can be implemented in adjustable receiver 200, and method 400 is described with reference to adjustable receiver 200. Signals that are received in method 400 are transmitted by a base station 110 or other type of access point. Instructions or code can be stored in memory 250 that are executable by control processor 255 in adjustable receiver 200 of FIG. 2 to implement method 400.

Method 400 begins at block 410. At block 410 a narrowband control signal is received and processed by adjustable receiver 200. The control signal is referred to as a narrowband control signal because its band is typically less than data signals, as illustrated in the signaling scheme in Figure 3. In block 415, a decision is made as to whether a data signal follows the control signal in the TTI

Ί current. The control signal will contain this, and the control signal is demodulated to extract this information.

<td>If it is determined that no sign of</td><td>data follows the</td>

control signal in the current TTI, the method proceeds to block 440, in which the power provided to certain

<td>RF front end components,</td><td>such as</td>

<td>amplifiers 215, analog filters 225,</td><td>and / or ADCs 230, is</td>

<td>reduced to place the components</td><td>in a state of</td>

microsleep. Control processor 255 can send signals to components in receiver 200 to monitor their status as previously described. After a period of time, at block 445 the components are ordered to turn on or wake up to prepare to receive another control signal at block 410. The receiver 200 can wait until just before the start of the next TTI to request the components front end RF that wake up.

If in block 415 it is determined that a data signal does follow the control signal, the method proceeds to block 420. In. block 420, a front end. RF 2.12a of receiver 200 is adjusted to receive the data signal. Such

<td>as previously described, the signal</td><td>control can</td>

<td>contain information regarding the width of</td><td>expected band of</td>

<td>the data signal. Alternatively,</td><td>bandwidth</td>

of the data signal can be understood as a certain value. In either case, the front end RE is adjusted. Control processor 255 controls the setting. The 245 baseband processor can also be tuned.

Then at block 425 the data signal is received and processed. After the data signal is received at block 425, the. front end RE is adjusted to receive a control signal at block 430 and the method returns to block 410 to start again. Method 400 continues as long as desired for a communication session. In some embodiments, a control signal is transmitted at the start of each TTI, and no additional control signals are transmitted within each TTI. In other embodiments, at least one additional control signal is transmitted on each

TTI. For example, there may be a control signal at the start of a TTI and another control signal in the middle of the TTI.

Figure 5 illustrates another frame format 510 and the power consumption of an RF front end 560 during reception of the illustrated frame format. Frame format 510 is a TDM format in which time is divided into transmission time slots (TTIs) and control signals and data signals are multiplexed by time division. Figure 5 illustrates a transmitted signal sequence within this 510 frame format.

The signal sequence transmitted in the frame format

510 It is different from frame format 310 in that if one data signal is transmitted, the next control signal is transmitted using the bandwidth as the data signal so that there is no switching time or switching interval to set a RF front end.

Because there is no need to adjust the front end

RF, a data signal can be transmitted up to the TTI limit. The signaling format offsets the potential for energy savings with a narrower band control signal against the benefit of being able to eliminate signaling downtime due to switching. Therefore, the signaling scheme uses control signals

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The signaling in Figure 3 can be understood with reference to Figure 6. Figure 6 is a flow chart illustrating an exemplary method 600 for receiving control signals and data. In Figure 6, blocks 410-425, 440, and 445 are the same as the corresponding blocks in Figure 4.

After a data signal is received in the block

425, method 600 proceeds to block 610 in which it receives

<img file="MX368489B_D0002.tif" />

a broadband control signal. The control signal can be referred to as a broadband control signal because the bandwidth is the same as the previously received data signal, and the bandwidth of the data signal is typically larger than the width band of the narrowband control signal. The control signal 515 in the frame format 510 in Fig. 5 is an example of the narrowband control signal, and the control signal 530 is an example of the wideband control signal. Narrowband control signal 515 is followed by a transition period 520 to allow an RF front end to adjust to receive data signal 525. There is no necessary transition period between data signal 525 and control signal 530 because the bandwidths are the same.

As previously discussed with respect to FIG. 3, frame format 510 may furthermore contemplate FDM among users. For example, the bandwidth B data signal 525 may be divided into the frequency domain with different portions of bandwidth B assigned to different users. Similarly, the control signal 530 can be similarly divided. The RF 212 front end for a user can continue to be appropriately adjusted for bandwidth B with desired 1st portion extraction and demodulation being digitally executed in the frequency domain using OFDM techniques.

Next in decision block 615, a determination is made as to whether a data signal follows the broadband control signal in the TTI. If the data follows the broadband control signal, in one mode, then the data is transmitted on the same bandwidth as the control signal, so there is no need to adjust the RF front end, and the data is received at block 620. In another embodiment, the data is generally transmitted over a bandwidth B that may be larger or smaller than the bandwidth of the control signal, so that there may be a transition period during which the RF front end It is adjusted to receive the signal, data.

On the other hand, if there is no data signal following the broadband control signal then method 600 proceeds to block 440. In block 440, the power provided to certain RF front-end components, such as amplifiers 215 Analog filters 225, and / or ADCs 230, is reduced to place the components in a microsleep state. After a period of time, at block 445 the components receive the instruction to

2 turn on or wake up to prepare to receive another control signal · at block 410. Receiver 200 can wait until just before the start of the next TTI to request that the RF front end components wake up. As part of the wake-up process, the RF front end bandwidth and sampling rates are set to receive a narrowband control signal. Instructions or code can be stored in memory 250 of adjustable receiver 200 which are executable by control processor 255 to implement method 600.

Figure 7 illustrates an example of the frame and signal structure for an FDM system. The carrier frequency for designated data for a given UE is not fixed and may vary. In the FDM scheme, the total bandwidth of the system can be divided into a plurality of frequency bands so that the data signals for different UEs can be transmitted simultaneously in different frequency bands. For example the data signal for the UEi 710 and the data signal for the UE? 720 overlap in time during the TTIi but do not overlap in frequency. A carrier signal at the center frequency of each of the data signals illustrated in Figure 7 is used to transmit the various data signals.

The bandwidth allocated for data signals for a

3

A given UE may vary over time, as illustrated by comparing data signals 710 and 730 directed to the UEi, for example. A base station may decide to modify the bandwidth for a particular UE due to variations in the amount of data available for transmission versus time, for example.

Some conventional FDM schemes transmit OFDM signals using the full bandwidth available for downlink transmissions, with different groups of subcarriers within the full signal assigned to different UEs. As a consequence, each UE typically

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RF carrier that is being used for your signals. However, the benefit of the multi-RF approach is that bandwidth can be used more efficiently if the data signals are allowed to use different RF carriers so that each UE does not have to process the full bandwidth and You can use the RF carrier dedicated to it.

Figure 8 is a protocol diagram illustrating the signaling aspects between a UE 120 and a base station

110 to support FDM with variable bandwidths. In this example, control signals are transmitted over a different channel from the data signals. The control channel may be in a different frequency band or in a different time slot, as an example. A control signal indicates the center frequency (if the center frequency is dynamic) and the bandwidth of an associated data signal. The data signal is then sent using the designated bandwidth and center frequency. In a time interval between the control signal and the data signal, the receiver of the UE 120 is tuned to the bandwidth of the data signal. This process is repeated as long as there is data to transmit between base station 110 and UE 120.

Base station 110 can coordinate this process through different UEs 120 to efficiently use the available spectral bandwidth. An example of this coordinated process was described with respect to figure 7.

FIG. 9 is a protocol diagram illustrating the signaling aspects between a UE 120 and a base station 110 to support variable bandwidth signaling. First, UE 120 transmits a capacity message to base station 110. The capacity message may provide

5 one or more indications corresponding to a number of parameters and capabilities of the UE 110. The capacity message may include an indication as to whether the UE 110 can dynamically switch between signals of various bandwidths. The capability message may further include an indication of switching latency for the UE 120, so that the base station 110 can respond by inserting or reserving a time interval between control signals and data to allow the UE 120 to adjust its front end RE. The time interval accommodates the switching latency indicated by a UE.

The base station 110 then transmits a response message to the capacity message. The response message may provide one or more indications corresponding to a number of parameters and capabilities. For example, the response message may indicate that dynamic bandwidth switching is on. Dynamic bandwidth switching can be enabled or disabled as often as desired during a connection. Therefore, messages indicating that dynamic bandwidth switching is on or off can be transmitted by base station 110 as often as desired.

The response message may also indicate the time offset between a control signal and the corresponding data signal in a TTI. Time offset can be based on the switching latency indicated in the capacity message. The time offset would accommodate the latency necessary to decode the control signal and allow the RF front end to switch bandwidths. The response message can also indicate whether the bandwidth is maintained at a wide bandwidth of the data signal for the next control signal, as illustrated in Figure 5, or returns to a narrow bandwidth, as illustrated in figure 3. Alternatively, a pre-control signal can also indicate whether the bandwidth is maintained at a wide bandwidth of the data signal for a subsequent control signal, as illustrated in Figure 5, or returns to a width of narrow band, as illustrated in figure 3.

Alternatively, base station 110 may decide not to activate dynamic bandwidth switching. If dynamic bandwidth switching is not enabled, the control signals occupy the same bandwidth as the data signals, and there is no time offset between control signals and data signals.

After the capacity message and response message have been exchanged, transmission of control information and data can then proceed as required. In the example shown in Figure 9, a control signal is transmitted by base station 120 and received by UE 110. Ά Next, UE 110 adjusts its front end RF, and then a data signal is transmitted by the station base 120 and is received by the UE 110.

FIG. 10 is a block diagram of a transceiver 900 that implements aspects of this disclosure. Transceiver 900 comprises antennas 210, baseband processor 245, memory 250, and controller / processor 255 as previously described. The transceiver further includes RF 910 receive (Rx) front ends. Each Rx RF 910 front end may include an amplifier, an analog filter, and an ADC as described with respect to Figure 2. Other Rx RF front end architectures support this disclosure. For example, some Rx RF front end architectures do most of the processing in the analog domain, and some Rx RF front end architectures do most of the processing in the digital domain. Also, some Rx RF front end architectures do most of the processing at an intermediate frequency rather than in the baseband. These front ends Rx

RF can be adjustable to accommodate differences in the bandwidths of the control signal and the data signal.

The transceiver further includes RF 920 transmit (Tx) front ends. Each Tx RF 920 front end accepts a stream of digital data symbols from the baseband processor and converts the digital data symbols to an analog signal for transmission over the corresponding antenna. 210.

The transceiver 900 is suitable for either a base station 110 or a UE 120. When the transceiver 900 is in a transmit mode, the front ends Tx RF 920 are involved, and the controller / processor 255 controls the front ends Tx RF 920 as well as the 245 baseband processor to generate signals of various 15band widths. The combination of Tx RF 920 front end and 245 baseband processor is an example of a transmitter.

The combination of Rx RF 910 front end and 245 baseband processor is an example of a receiver. A front end Rx RF 910 may comprise the front end RF 212 20 previously described.

In addition to the previously described capabilities for demodulating OFDM symbols, the baseband process 245 can additionally be configured to modulate OFDM symbols. OFDM symbol modulation is muv known in the art and, in some embodiments, an inverse FFT (IFFT) is executed to convert the frequency domain data to the time domain. As previously described, there are several techniques for changing OFDM signal bandwidths. One technique involves modifying the number of subcarriers used to generate OFDM signals.

Information and signals can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced in the foregoing description may be represented by voltages, currents, electromagnetic walkways, magnetic fields or particles, optical fields or particles, or any combination thereof.

Figure 11 illustrates another frame format 1110. The frame format is a TDM format in which time is divided into TTIs and control signals and data signals are time multiplexed. Figure 11 illustrates a transmitted signal sequence within this 1110 frame format.

Control signals. 1115 are narrowband control signals. In one embodiment, a base station allows a full TTI duration for bandwidth switching delay of a receiver. There are at least two options for signaling using 1115 control signals.

n a first option, the control signal 1115 in the TTI_n has a bandwidth switching indicator to trigger RF front end bandwidth spreading to receive wider bandwidth data in the TTI_n+ i · In this option, the control signal 1115 in the TTI_{n +}i. indicates the frequency range that is assigned for data in the TTI_{n +}i. In a second option, the data radio block allocation 1125 in the TTI_{n + i} is assigned or previously programmed using control signal 1115 in the TTI_n. Once a wide radius front end bandwidth is established for the TTI_{n +}i, programming can return to normal (i.e. not previously programmed) for

Subsequent TTIs. For example, the 1115 control signal on the TTI_{n +}2 indicates the use of data resources 1135 and 1145 in the rn rp * r

111

An advantage of the first option is that the programmer at a base station only needs to know that the UE will be programmed at the next TTI to adjust the indicator. The base station programmer does not need to pre-program and avoids a corresponding increase in complexity. An advantage of the second option is that there is a saving of a control channel resource since there is no bandwidth switching indicator.

The receiver bandwidth envelope is indicated in Figure 11. The receiver bandwidth envelope represents the frequency range versus time used by a receiver, such as the adjustable receiver 200, in the frame format of interest. During the transition period 1120 the receiver bandwidth can transition from relatively narrow bandwidth for receiving control signal 1115 to relatively wide bandwidth (in this mode, the full bandwidth of the system or the full bandwidth available for data) for receiving data. Similarly, during transition period 1130, the receiver bandwidth can transition from relatively wide bandwidth to relatively narrow bandwidth as shown.

Figure 12 illustrates another frame format 1210. In this frame format, a data signal can be assigned only for a subsequent fraction or portion of a TTI, so there is sufficient time for the receiver bandwidth to perform the transition from narrow bandwidth to receive a control signal to wider bandwidth to receive a data signal. For example, in TTI_n control signal 1215 may indicate that there will be a data signal 1225 later in the TTI. Therefore, a shorter duration of a TTI than the example in Figure 11

2 may be available for receiver bandwidth switching. During transition period 1220 the receiver bandwidth is increased. An example of this type of receiver boost is illustrated by the receiver bandwidth wrapper in Figure 12.

Once the receiver transitions to a wider bandwidth in TTI_n, the. Data allocation could cover the entire TTI, including the option to multiplex with the frequency control channel. For example, signal 0 control 1215 in TTI_n+ i can indicate the bandwidths of the 1235 and 1245 data signals. Control signals that are transmitted after the receiver has transmitted at a higher bandwidth may be referred to as broadband control signals, and in some modalities, a broadband control signal 5 refers to a control signal and one. or more data signals that are transmitted simultaneously in different frequency bands (ie, frequency division multiplexed). An example of a broadband control signal is the control signal 1215 0 at TTIn + i in Figure 12, and this control signal is frequency division multiplexed with the data signals 1235 and 1245. In some embodiments, During a time interval in which a broadband control signal is transmitted, the transmitted signal includes a

<img file="MX368489B_D0003.tif" />

control signal portion and a data signal portion.

Figure 12 also illustrates a down count mechanism for returning a receiver to a narrow band for receiving control signals - In TTI_{n + 2}, the control signal 1215 indicates that there is no data within the TTI_nt2. Therefore, the TTI_n+2 is a candidate to return the receiver bandwidth to a narrow bandwidth using previously described mechanisms - for example with respect to figure 2. However, instead of having a receiver transition frequently between bandwidths, a down count mechanism is used. In the first TTI in which there is no data to transmit, a counter is set to a maximum value, such as four, three, two, one, or any integer value. In the embodiment of Figure 12, the maximum value is one. The. Counter is decremented each successive consecutive TTI that contains no data. If a TTI does contain data, the counter is reset Figure 12, in the TTI_{n + 3}, the counter is decreased to the maximum value. In the example of if there is no data to transmit, to zero. A counter value of zero indicates that the receiver should then reduce its bandwidth. For example, in the TTI_n+3, the receiver reduces its bandwidth as shown (the receiver wrapper transitions from wide bandwidth to narrow bandwidth during the transition period

1230) . An alternative to the countdown timer is that the receiver bandwidth is reduced to narrow bandwidth in the first TTI that contains no data.

Figure 13 illustrates another 1310 frame format. The 1310 frame format is similar to the 1110 frame format, except that for the 1310 frame format, a mode of a receiver is enhanced with bandwidth adaptation according to allocation. of data. For example, in Figure 11 during TTI_{n +}i the receiver bandwidth is set to the system bandwidth or maximum supported data bandwidth, while in figure 13 the receiver bandwidth during TTI_n&lt;-i is set large enough to receive the 1325 data signal while remaining symmetric around frequency f_c.

Also, as in the figure

11, there are at least two options for signaling using 1115 control signals. In a first option, the 1115 control signal in the TTI_n It has a bandwidth switching indicator plus bandwidth information to trigger the RF front end bandwidth spreading to be wide enough to receive wider bandwidth data on the TTIn + i. In a second option, the assignment of the data radio block 1125 in the ΤΤΙ_{η + Ί} is assigned or previously

<img file="MX368489B_D0004.tif" />

programmed using the 1115 control signal on the TTI_n. Once a wide radius front end bandwidth is set for a ΤΤΙη + ι, scheduling can return to normal (i.e. no pre-scheduling) for subsequent TTIs. For example, the control signal 1115 on the

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<td>How</td><td>An example</td><td>additional,</td><td colspan="2">signs</td><td>control 1115</td><td>at</td>

<td>rp rn T 111 n + 2</td><td>and the TTI</td><td>_{n +}3 indicate</td><td>than</td><td>not</td><td>there is data in what</td><td>s TTIs</td>

respectively, so that the receiver bandwidth remains narrow and the receiver can transition to a microsleep state.

Figure 14 illustrates another 1410 frame format. When using this 1410 frame format, the center frequency cannot remain the same regardless of the TTI. This frame format facilitates the use of a receiver that can vary its center frequency and the front end bandwidth RE. The receiver bandwidth envelope is indicated.

The bandwidth of a receiver is centered at a frequency in the center of the signal, control 1,415 in the TTI_n and then the center is shifted during transition period 1420 to the frequency at the center of data signal 1445.

This 1410 frame format combined with 1st programming

6 Previewing data signals 1445, 1455, and 1465 using control signal 1415 implies that control signals 1425 can be ignored by a receiver configured to receive data signals 1445, 1455, and 1465. As illustrated in Figure 14 Preprogramming of fractional TTIs can be run for data signals. For example, the data signals 1445 and 1465 occupy a fraction of a time interval TTI, and the duration of the data signals may be indicated by the control signal 1415. After the data signal 1465, the front end RF it can be re-tuned to a bandwidth for control signal 1435 during transition period 1430.

Figure 15 illustrates another 1510 frame format. The 1510 frame format is an example of the. TDM format in which control signals and data signals are received by a UE, and acknowledgment messages (ACKs) are transmitted by the UE in response to receiving data signals. In one embodiment, an ACK is used to indicate whether all or part of a preceding data signal was successfully received. In this 1510 frame format, the RF front end bandwidth of a receiver is maintained at the system bandwidth or maximum available data bandwidth until a TTI is received that does not have a data allocation. For example, in the TTI_n+2, the

7 control signal 1535 indicates that there is no data in the TTI so that a receiver can reduce its bandwidth during transition period 1530 as shown. Protection periods can be inserted on either side of an ACK. For example, protection periods 1544 and 1546 are inserted on either side of ACK 1445.

An exemplary embodiment of programming data signals in accordance with frame format 1510 is as follows. The 1515 control signal on the TTI_n it can be used to program the 1565 data signal by a fraction of the TTI. After receiving the control signal 1515, a receiver transitions its RF front end bandwidth to receive the data signal 1565 as shown. Alternatively (not shown), the 1515 control signal on the TTI_n could carry the bandwidth switching indicator or pre-scheduling information, similar to the scheme described in figure 11, and the data allocation is deferred until TTI_{n +}i. This scheme avoids the allocation of data RBs only for a fraction of the TTI (as in 1565), at the expense of a delayed start for data transfer. Subsequently, the RF front end bandwidth is maintained at a wide bandwidth until, that a control signal in a TTI indicates that there is no data in the TTI. Narrowband control signal 1525 indicates that data signal 1575 is present, so that the receiver is configured to receive the data signal. Control signal 1525 can use a subset of the available subcarriers, and the portion of data signal 1575 that is simultaneous with control signal 1525 can occupy the remaining available subcarriers. Control signal 1535 indicates that there is no data in the TTI_{n +}2, so that the receiver reduces its RF front end bandwidth and can also transition to a microsleep state during transition period 1530.

Some advantages of the 1510 frame format include the following. First, for consecutive TTI data allocation, once the overhead is paid for RF bandwidth spreading (causing delayed start of data radio blocks), in the subsequent TTI there is no radio block overhead. of data. Second, improvements for broadband-narrowband transitions, such as a countdown timer or bandwidth switching indicator described with respect to Figure 12, could also be applied.

Figure 16 illustrates another 1610 frame format. The 1610 frame format is an example of the TDM format in

9 which control signals and data signals are received by a UE, and ACKs are transmitted by the UE in response to receiving data signals. An example of a data signal programming mode according to the 1610 frame format is as follows. The 1615 control signal on the TTI_n It can be used to program data signal 1620 for a fraction of the TTI. After receiving the control signal 1615 a receiver transitions its bandwidth from the RF front end to receive the signal, data 1620 as shown. The receiver switches back to narrow bandwidth for receiving each control signal as shown. For example, the receiver transitions to narrow bandwidth during transition period 1640 and then receives control signal 1625 using narrow bandwidth as shown. An advantage of the 1610 frame format may include that the bandwidth switching behavior is the same across TTIs.

Once the way in which the raster formats in Figures 3 and 5 can be implemented using the adjustable receiver 200 as previously described is appreciated, it is readily understood that the raster formats in Figures 11-16 can be implemented in a direct way using the adjustable receiver 200.

The various illustrative logic blocks and modules described in connection with the present disclosure may be implemented or executed with a general-purpose processor, DSP, ASIC, FPGA, or other programmable logic device, discrete gate or transistor logic, hardware components discrete, or any combination thereof designed to perform the functions described here. A general-purpose processor may be a microprocessor, but on the. Alternatively, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor can also be implemented as a combination of computing devices (eg, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a core DSP, or any other such configuration).

The functions described here can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored in or transmitted on, such as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of the software, the functions described above may be implemented using software run by a processor, hardware, firmware, hard wiring, or combinations of any of these. Characteristic features that implement functions can also be physically located in various positions, including distributed so that portions of the functions are implemented in different physical locations. Also, as used herein, including in the claims, or as used in an item list (eg, a list of items preceded by a phrase such as at least one of or one or more than) indicates one. inclusive list such as, for example, a list of [at least one of A, B, or C] means A or B or C or AB or AC or BC or ABC (ie, A and B and C).

As those skilled in the art will now appreciate, and depending on the particular application, many modifications, substitutions, and variations can already be made in the materials, apparatus, configurations, and methods of use of the devices of the present disclosure without departing from the spirit and scope of it. By virtue of this, the scope of the present disclosure should not be limited to that of the particular modalities illustrated and described here, since they are simply by way of some examples thereof, but rather, should be broadly commensurate with that of the appended claims hereinafter and their functional equivalents.

3

NOVELTY OF THE INVENTION

Having described the present invention, it is considered as a novelty and, therefore, the content of the following is claimed as property: