CN110572196A

CN110572196A - wireless virtual reality system based on distributed antenna

Info

Publication number: CN110572196A
Application number: CN201910809798.7A
Authority: CN
Inventors: 王旭; 陈南希
Original assignee: Shanghai Institute of Microsystem and Information Technology of CAS
Current assignee: Shanghai Institute of Microsystem and Information Technology of CAS
Priority date: 2019-08-29
Filing date: 2019-08-29
Publication date: 2019-12-13
Anticipated expiration: 2039-08-29
Also published as: CN110572196B

Abstract

The invention relates to a wireless virtual reality system based on a distributed antenna, which comprises a host and a helmet, wherein the host comprises 8 remote radio units. The 8 radio remote units are respectively in two different working modes, wherein 1 radio remote unit sends high-definition video and high-fidelity audio to the helmet; meanwhile, the other 7 radio remote unit wheels send channel detection signals to the helmet. When an obstacle appears between one remote radio unit and the helmet, the remote radio unit can be quickly switched to other remote radio units, so that the problem of signal shielding can be effectively solved, and high-speed data transmission between the host and the helmet is ensured. In addition, the remote radio unit adopts an analog beam forming technology, the helmet adopts a mixed analog/digital beam forming technology, and a radio frequency channel for receiving channel detection signals uses a low-precision analog-to-digital converter, so that the hardware complexity and the power consumption of the system can be effectively reduced.

Description

wireless virtual reality system based on distributed antenna

Technical Field

The invention relates to the field of virtual reality, in particular to a wireless virtual reality system based on a distributed antenna.

Background

With the continuous progress of computer science, the man-machine interaction technology is also rapidly developed. In the early DOS command line environment, the user was only able to use the keyboard to enter commands. In the microsoft windows operating system, a user can operate through a mouse. In recent popular smart phones, the android system and the apple iOS system both allow a user to directly operate through a touch screen. In these systems, although the operation of the user is more and more simple and convenient, the display device is based on a two-dimensional plane. In practice, people live in a three-dimensional space. There are various limitations to using two-dimensional planes to describe objects in three-dimensional space. In recent years, virtual reality technology has been rapidly developed. The virtual reality technology can directly show a three-dimensional space to a user, so that human-computer interaction is completed in a mode more conforming to the daily life habits of people. In a virtual reality system, a user wears a virtual reality helmet to receive information transmitted from a computer host, thereby experiencing a virtual world entirely simulated by the computer.

different from the traditional computer, in order to enable the user to complete human-computer interaction by adopting the same body posture as that of daily life, the computing unit and the display unit of the virtual reality system are positioned at different positions in a physical space. This leads to an important problem: how to pass the result of the calculation unit to the display unit. One feasible method is to use cables such as HDMI, DP, USB for data transmission by using traditional computer, which has the advantage of ensuring high-speed and reliable data transmission, and the disadvantage that a user drags a physical line behind the helmet to connect with the host computer when using the virtual reality system. This cable limits the range of motion of the user and may entangle or trip the user as the user moves.

the wireless virtual reality system utilizes wireless communication technology to transfer data from the host computer to the helmet. Due to the fact that the constraint of cables is avoided, the user can move freely and perform various complex human-computer interactions, and therefore user experience is improved remarkably. The virtual reality system needs to transmit high-definition video, and the requirement on bandwidth is high. The bandwidth of the millimeter wave frequency band is large, and the data transmission rate is high. Therefore, the wireless virtual reality system generally adopts a millimeter wave frequency band for data transmission. However, an important disadvantage of millimeter wave communication is the short wavelength and poor diffraction capability when encountering obstacles. In the case of a direct path, the millimeter wave communication can provide a sufficient transmission speed to perform transmission of high definition video. However, when there is an obstacle between the host and the helmet, the transmission speed of the millimeter wave communication is drastically reduced. For example, during use of the virtual reality system, the user may inadvertently block the wireless signal due to movement of the head, arms, or other body parts. In addition, if a plurality of users use the virtual reality system at the same time, the situation of mutual occlusion between different users is inevitable. If a wireless signal is transmitted from a fixed position, no matter how the position of the transmitting antenna is selected, the occurrence of the signal shielding phenomenon cannot be completely avoided.

Patent application No. 201710085582.1 provides a wireless virtual reality system, which can compress video data and then perform wireless transmission, and can reduce the requirement of the virtual reality system on the wireless transmission rate by reducing the data volume. However, this method has the following disadvantages: on the one hand, video compression can reduce the quality of the video, thereby affecting the user experience; on the other hand, the calculated amount of compression and decompression of the video is large, which can increase the power consumption of the virtual reality helmet, and for the virtual reality helmet powered by a battery, the increase of the power consumption can shorten the service time of the virtual reality system, thereby affecting the user experience. In addition, the virtual reality system has a strict requirement on delay, and certain time is inevitably consumed for compressing the video at the transmitting end and decompressing the video at the receiving end, which increases the delay of the system, thereby causing a user to feel dizzy when wearing the virtual reality helmet.

disclosure of Invention

The invention provides a wireless virtual reality system based on a distributed antenna, which comprises a host and a helmet, wherein the host is connected with the helmet through a wireless network; the host comprises 8 radio remote units which are respectively arranged at 8 top points of a room; the remote radio unit comprises 1 remote radio unit and a plurality of remote radio units, wherein the 1 remote radio unit is used for sending high-definition video and high-fidelity audio to the helmet; meanwhile, the other 7 radio remote unit wheels send channel detection signals to the helmet.

in the invention, the host is provided with a radio remote unit at each of 8 vertexes of a room. If an obstacle exists between one remote radio unit and the helmet, the remote radio unit can be switched to another remote radio unit to communicate with the helmet. Because all the vertexes of the room are uniformly provided with the radio remote units, the direct radiation path between at least one radio remote unit and the helmet can be ensured, and high-speed data transmission can be carried out.

Further, the host also comprises 1 baseband unit and 1 upper protocol unit; 8 radio remote units of the host share 1 baseband unit and 1 upper protocol unit; the baseband unit is used for processing baseband signals, and the upper layer protocol unit is used for processing all communication protocols above a Medium Access Control (MAC) layer.

optionally, the baseband unit may be implemented by a Field Programmable Gate Array (FPGA), an Application Specific Integrated Circuit (ASIC), or a Digital Signal Processor (DSP); the upper layer protocol unit can be realized by ASIC or general processor such as X86/64, ARM, etc.

furthermore, the wireless virtual reality system can realize the functions of 3 signal links, including a high-speed data transmission link, a channel detection link and a feedback link; the high-speed data transmission link is used for transmitting high-definition video and high-fidelity audio; the channel detection link is used for sending a channel detection signal; the feedback link is used for the helmet to feed back information to the host, and the feedback information comprises channel quality, operation commands of the user, signals of various sensors and the like.

furthermore, the bandwidth of the high-speed data transmission link is integral multiple of the bandwidth of the channel detection link and is represented by Q; the carrier frequency used by the high-speed data transmission link and the channel detection link is the same, and the carrier frequency is located in a millimeter wave frequency band.

furthermore, the radio remote unit also comprises an interpolator, a switch and two shaping filters; the interpolator is used for repeatedly inserting the value of each data point in the baseband signal into the data stream for Q times; one of the shaping filters conforms to the bandwidth of the high-speed data transmission link, and the other shaping filter conforms to the bandwidth of the channel detection link; the switch is used for switching the two shaping filters.

Specifically, the remote radio unit is responsible for transmitting both the high-speed data transmission link signal and the channel sounding link signal. When sending the signal of the channel detection link, the signal from the baseband unit passes through the interpolator, repeats the value of each data point in the baseband signal for Q times and inserts the value into the data stream, then enters the analog circuit through the digital-to-analog converter, passes through the shaping filter, and the shaping filter is switched through the switch. After the signal comes out of the shaping filter, the up-conversion, power amplification and other circuit modules of the high-speed data transmission link are still used.

Furthermore, the remote radio unit adopts an analog beam forming technology.

Further, the helmet employs a hybrid analog/digital beam forming technique, and the helmet includes a first radio frequency channel and a second radio frequency channel; the first radio frequency channel is used for receiving signals of the high-speed data transmission link; the second radio frequency channel is used for receiving signals of the channel detection link.

Furthermore, a high-precision analog-to-digital converter is used for a high-speed data transmission link of the helmet, and a low-precision analog-to-digital converter is used for a channel detection link of the helmet; wherein the precision of the high-precision analog-to-digital converter is at least 4 bits higher than that of the low-precision analog-to-digital converter.

further, the feedback link adopts a frequency band below 6 GHz; the helmet comprises 1 signal transmitting module of a feedback link, wherein the signal transmitting module comprises 1 transmitting antenna; the host comprises 1 signal receiving module of a feedback link, and the signal receiving module is positioned in any one of 8 remote radio units; the signal receiving module comprises 1 receiving antenna.

Further, the host also comprises a high-performance display card for generating and rendering images; the helmet further comprises a display screen, an earphone, a gyroscope and an eyeball tracking sensor. The wireless virtual reality system also comprises a handle, and the handle is connected with the helmet.

further, the workflow of the wireless virtual reality system comprises:

Step S1: initializing a wireless virtual reality system; each remote radio unit carries out exhaustive search of the beam direction and records the azimuth angle from the remote radio unit to the helmet; in the horizontal direction, only 90 degrees, namely 1/4 plane, need to be searched; in the vertical direction, only 90 degrees, namely the upper half space or the lower half space, need to be searched; the helmet carries out exhaustive search in the horizontal direction of 360 degrees and the vertical direction of 180 degrees, and records the azimuth angle from the helmet to each remote radio unit;

Step S2: the helmet calculates the signal intensity from each remote radio unit to the helmet, and selects the remote radio unit with the best channel quality to determine as the first remote radio unit for high-speed data transmission;

step S3: the helmet sends the selected information of the first remote radio unit to the host through a feedback link;

Step S4: the wireless virtual reality system is in a normal working state; the host machine completes the generation and rendering of images by using the high-performance display card, and then sends high-definition video and high-fidelity audio to the helmet through the first radio remote unit; the rest 7 radio remote units which are not selected by the helmet send channel detection signals to the helmet in turn at preset time intervals;

Step S5: the helmet receives high-definition video and high-fidelity audio transmitted by a host through a first radio frequency channel provided with a high-precision analog-to-digital converter, plays a video signal through a display and plays an audio signal through an earphone; meanwhile, the helmet sequentially points the wave beam to each radio remote unit through a second radio frequency channel provided with a low-precision analog-to-digital converter and receives a channel detection signal;

Step S6: the helmet continuously updates the channel quality from the helmet to each remote radio unit according to the channel detection signal; meanwhile, the helmet collects feedback information including confirmation information of successful transmission of the video and audio signals, various operation instructions of the handle, user posture information provided by the gyroscope, the gazing direction of the eyes of the user and the like provided by the eyeball tracking sensor, and sends the feedback information to the host through a feedback link;

Step S7: if the helmet finds that the signal quality of the high-speed data transmission link is rapidly reduced, judging that an obstacle is encountered, and turning to the step S8; otherwise go to step S4;

Step S8: the helmet selects the radio remote unit with the best channel quality from the rest 7 radio remote units to determine the radio remote unit as a first radio remote unit, and feeds back the information of the newly selected first radio remote unit to the host through a feedback link;

Step S9: after the host receives the feedback of the helmet, the newly selected first remote radio unit belongs to the high-speed data transmission link instead; the radio remote unit originally used for high-speed data transmission belongs to the channel detection link instead.

the utility model provides a pair of wireless virtual reality system based on distributed antenna has following technological effect:

1) By adopting a distributed antenna technology, radio remote units are installed at 8 vertexes of a room, and when an obstacle appears between one radio remote unit and a helmet, the radio remote units can be switched to other radio remote units.

2) The remote radio unit adopts an analog beam forming technology, and the helmet adopts a mixed analog/digital beam forming technology, so that the power consumption and the hardware complexity can be reduced.

3) the high-speed data transmission link uses a high-precision analog-to-digital converter, and the channel detection link uses a low-precision analog-to-digital converter, so that the power consumption of the analog-to-digital converter in the helmet can be reduced.

4) The 8 remote radio units share the baseband module and the upper protocol module, and the helmet logically belongs to the same cell no matter which remote radio unit the helmet carries out data transmission with, so cell switching is not needed when the remote radio units are changed; in addition, the helmet continuously updates the channel quality between the remote radio units and the helmet and saves the azimuth angle of the beam, so that the beam search is not needed when the signal shielding problem occurs, and the remote radio units can be switched quickly.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic diagram of an application environment provided by an embodiment of the present application;

Fig. 2 is a schematic diagram of a workflow of a wireless virtual reality system based on a distributed antenna according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic may be included in at least one implementation of the present application. In the description of the present application, it is to be understood that the terms "upper", "lower", "top", "bottom", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," and the like are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein.

referring to fig. 1, fig. 1 is a schematic diagram of an application environment provided in an embodiment of the present application, including a host 101 and a helmet 101, where the host includes 8 Remote Radio Units (RRUs) 102; assuming that a room in which the virtual reality system is placed is a cuboid, 8 remote radio units 102 are respectively installed at 8 vertices of the room. The 8 remote radio units 102 are respectively in two different operation modes: the 1 radio remote unit 102 is used for sending high-definition video and high-fidelity audio to the helmet 101; the other 7 remote radio units 102 are used for transmitting channel detection signals to the helmet 101 in a round-robin manner.

In this embodiment, the host further includes 1 baseband unit and 1 upper protocol unit. The baseband unit is responsible for processing baseband signals, and the upper protocol unit is responsible for processing all communication protocols above a Medium Access Control (MAC) layer. The 8 remote radio units 102 share 1 baseband unit and 1 upper protocol unit.

The embodiment of the application adopts a millimeter wave communication technology to transmit high-definition videos and high-fidelity audios. The bandwidth of the millimeter wave frequency band is large, so that the data transmission speed can be improved. A common millimeter wave system deployment method in the prior art is that one macro station carries a plurality of millimeter wave stations. Under the structure, each millimeter wave small station is an independent entity and respectively sends own wireless signals. And at the overlapping position of the coverage areas of the two millimeter wave small stations, the macro station is responsible for coordinating signals of the two millimeter wave small stations so as to reduce mutual interference as much as possible. If the user moves from the coverage area of one millimeter wave small station to the coverage area of another small station, the registration information of the user in the wireless network needs to be transferred from the previous millimeter wave small station to the next millimeter wave small station by using a cell switching process.

In the wireless virtual reality system based on the distributed antenna provided in the embodiment of the present application, 8 remote radio units 102 share 1 baseband unit and 1 upper protocol unit. The advantages of this are: on the one hand, no matter which remote radio unit 102 the helmet 101 performs data transmission with, the helmet 101 logically belongs to the same cell, so cell handover is not required. If an obstacle occurs between the currently used remote radio unit 102 and the helmet 101, the user can immediately switch to another remote radio unit 102 for data transmission. In the structure of "macro station with multiple millimeter wave stations", the new remote radio unit 102 can be used for data transmission only after cell handover is completed. This can result in a transmission interruption for a period of time. For example, in the LTE system, the time required for cell handover is approximately 50 milliseconds. In the virtual reality system, if the delay time exceeds 20 ms, the user may feel dizzy. On the other hand, in the structure of "macro station with multiple millimeter wave small stations", each millimeter wave small station needs 1 baseband unit and 1 upper layer protocol unit. A total of 8 baseband units and 8 upper layer protocol units are required for 8 mm wave stations. In the embodiment of the application, only 1 baseband unit and 1 upper-layer protocol unit are needed in total, so that the complexity of hardware is effectively reduced. In addition, the distributed antenna system does not need to be equipped with a special device similar to a "macro station" to coordinate the operations of the multiple remote radio units 102, thereby further simplifying the hardware structure.

Optionally, the baseband unit may be implemented by an FPGA, an ASIC, or a DSP; the upper layer protocol unit can be realized by ASIC or general processor such as X86/64, ARM, etc.

In millimeter wave communications, it is necessary to compensate for path loss using massive antenna techniques. If each antenna is equipped with a separate radio frequency channel (RF chain), the hardware cost is very high and the power consumption is huge. In the embodiment of the present application, the remote radio unit 102 employs an Analog Beamforming technology (Analog Beamforming), that is, all antennas installed on one remote radio unit share 1 radio frequency channel. Thus, cost and power consumption can be reduced.

In the embodiment of the application, the wireless virtual reality system realizes 3 data links, including a high-speed data transmission link, a channel detection link and a feedback link; the high-speed data transmission link is used for sending high-definition video and high-fidelity audio to the helmet 101 by the host; the channel detection link is used for the host to send a channel detection signal to the helmet 101; the feedback link is used for the helmet 101 to feed back information to the host, and the feedback information includes channel quality, operation commands of the user, signals of various sensors, and the like.

During data transmission, once an obstacle is encountered between the currently transmitting remote radio unit 102 and the helmet 101, the remote radio unit 102 is switched to another remote radio unit 102. To minimize the time required, it is necessary to know in advance which remote radio unit 102 the beam should be directed at, and the corresponding azimuth angle of the beam. This means that data transmission and scanning of the alternative beam are performed simultaneously. In the embodiment of the present application, the channel sounding link is used for scanning the alternative beams. While 1 remote radio unit 102 performs high-speed data transmission with the helmet 101, the remaining 7 remote radio units 102 transmit channel sounding signals to the helmet 101 in turn.

In the embodiment of the application, the bandwidth of the high-speed data transmission link is an integral multiple of the bandwidth of the channel detection link and is represented by Q; the carrier frequency of the channel detection link is the same as that of the high-speed data transmission link, and the carrier frequency is located in a millimeter wave frequency band.

The channel sounding link does not require as much bandwidth as the high speed data transmission link. Typically, the channel sounding link only requires a maximum of 10MHz of bandwidth, and may be less in practice. While the bandwidth of high-speed data transmission links is often hundreds of MHz, or even GHz. Therefore, the bandwidth of the high-speed data transmission link is about 10-100 times of the bandwidth of the channel detection link. This means that the remote radio unit 102 needs to support the transmission of two bandwidth signals at the same time. One simple way is to design two rf channels to support the high speed data transmission link and the channel sounding link, respectively, but this increases the hardware complexity.

considering that each remote radio unit 102 only transmits a single bandwidth signal at the same time, the embodiment of the present application uses hardware devices of a high-speed data transmission link to transmit a channel sounding link signal with a small bandwidth.

in the embodiment of the present application, the radio remote unit includes an interpolator, a switch, and two shaping filters (pulse shaping); the interpolator is used for repeatedly inserting the value of each data point in the baseband signal into the data stream for Q times; one of the shaping filters conforms to the bandwidth of the high-speed data transmission link, and the other shaping filter conforms to the bandwidth of the channel detection link; the switch is used for switching the two shaping filters.

specifically, the bandwidth of the high-speed data transmission link is set to be an integral multiple of the bandwidth of the channel detection link, and is denoted by Q. Typical values for Q are 10 times, 20 times, 50 times, or 100 times. When sending the signal of the channel detection link, the baseband signal coming out of the baseband unit firstly passes through the interpolator, repeats the value of each data point in the baseband signal for Q times and inserts the value into the data stream, and then enters the analog circuit through the digital-to-analog converter. In analog circuits, the shaping filter determines the bandwidth of the transmitted signal. Therefore, in the embodiment of the present application, the remote radio unit 102 includes two shaping filters, one is used for the high-speed data transmission link, and the other is used for the channel sounding link. The two shaping filters are switched by a switch (switch). After the signal comes out of the shaping filter, the up-conversion, power amplification and other circuit modules of the high-speed data transmission link are still used.

Analog beamforming techniques, while low in hardware complexity, have the greatest disadvantage of being able to direct a beam in only one direction at a time. In the embodiment of the present application, the helmet 101 employs a Hybrid Analog/Digital Beamforming technology (Hybrid Analog/Digital Beamforming), and the helmet 101 includes a first radio frequency channel and a second radio frequency channel; the first radio frequency channel belongs to a high-speed data transmission link and is used for carrying out high-speed data transmission with a host. The second rf channel belongs to a channel sounding link, and beams are sequentially directed to each remote rf unit 102, and link quality of these channels is detected by receiving a channel sounding signal, so that the used remote rf units 102 can be switched in time when an obstacle occurs. In this way, the helmet 101 can simultaneously complete the reception of the signals of the high-speed data transmission link and the channel detection link.

The millimeter wave band, due to its large bandwidth, results in large power consumption of the analog-to-digital converter (ADC), which reduces the battery life of the helmet 101. In order to solve the above technical problem, in the embodiment of the present application, the high-speed data transmission link of the helmet 101 uses a high-precision analog-to-digital converter, and the channel detection link of the helmet 101 uses a low-precision analog-to-digital converter. Wherein the precision of the high-precision analog-to-digital converter is at least 4 bits higher than that of the low-precision analog-to-digital converter. This has the advantage that the channel sounding signal is only used to compare the quality of the channel from the head-mounted unit 101 to the respective remote radio units 102, and therefore does not require a particularly high accuracy. For example, the power consumption of an 8-bit precision analog-to-digital converter is 1/16 of that of a 12-bit precision analog-to-digital converter of the same speed. The channel detection link may use a low precision analog to digital converter to reduce power consumption.

alternatively, typical values for the accuracy of the high accuracy analog to digital converter are 10 bits and 12 bits.

Alternatively, typical values for the accuracy of the low accuracy analog to digital converter are 4 bits, 6 bits, 8 bits.

In the embodiment of the application, the feedback link adopts a frequency band below 6 GHz; the helmet 101 comprises 1 signal transmitting module of a feedback link, wherein the signal transmitting module comprises 1 transmitting antenna; the host comprises 1 signal receiving module of a feedback link, and the signal receiving module is positioned in any remote radio unit 102 in 8 remote radio units 102; the signal receiving module comprises 1 receiving antenna.

Optionally, the feedback link uses an unlicensed frequency band of 2.4GHz or 5 GHz.

The advantage of doing so is that, firstly, because the data volume of the feedback link is small, a large bandwidth is not needed, generally, only a bandwidth of 20MHz is needed at most, and actually, the bandwidth of the feedback link is much smaller than that of the high-speed data transmission link, and the frequency band which is not overlapped with the high-speed data transmission link can reduce the feedback delay; secondly, the feedback link adopts a frequency band below 6GHz, which is more robust to obstacles than the high-speed data transmission link and the channel detection link, so that the helmet 101 can feed back information of the obstacles to the host through the feedback link; thirdly, the feedback link does not need to be provided with an antenna array, so that the hardware circuit can be simplified; fourthly, since the wireless signals in the frequency band below 6GHz are robust to the obstacle, the host does not need to install a signal receiving module in each remote radio unit 102, and only needs to select one remote radio unit 102 from 8 remote radio units 102 for installation, so that the hardware circuit can be further simplified. Optionally, the signal receiving module may be installed in the remote radio unit 102 which is relatively open around.

in the embodiment of the application, the host further comprises a high-performance display card for generating and rendering the image. The helmet 101 also includes a display screen, headphones, a gyroscope, an eye tracking sensor, and the like. The helmet 101 receives the high-definition video and the high-fidelity audio sent by the host, transmits video information to the display screen to play video and transmits audio information to the earphone to play audio after demodulation is successful. The gyroscope is used for acquiring the attitude information of the user. The eye tracking sensor is used to capture the gaze direction of the user's eyes. The wireless virtual reality system further comprises a handle, the handle is connected with the helmet 101, and a user can use the handle to send out various commands and feed back the commands to the host through the helmet 101.

To sum up, the wireless virtual reality system provided by the embodiment of the present application has 8 remote radio units 102, and when an obstacle occurs between one remote radio unit 102 and the helmet 101, the remote radio unit 102 can be quickly switched to another remote radio unit 102, so that the problem of signal shielding can be effectively solved, and high-speed data transmission between the host and the helmet 101 is ensured. Meanwhile, the other remote radio units 102 transmit channel detection signals, so that the channel quality between the helmet 101 and each remote radio unit 102 is continuously updated, and the time required for switching the remote radio units 102 is reduced.

referring to fig. 2, fig. 2 is a schematic diagram of a workflow of a wireless virtual reality system based on a distributed antenna according to an embodiment of the present application, where the workflow includes:

step S1: initializing a wireless virtual reality system; each remote radio unit 102 performs exhaustive search of the beam direction and records the azimuth angle from each remote radio unit 102 to the helmet 101; in the horizontal direction, only 90 degrees, namely 1/4 plane, need to be searched; in the vertical direction, only 90 degrees, namely the upper half space or the lower half space, need to be searched; the helmet 101 performs exhaustive search in the horizontal direction of 360 degrees and the vertical direction of 180 degrees, and records the azimuth angle from the helmet 101 to each remote radio unit 102;

Step S2: the helmet 101 calculates the signal strength from each remote radio unit 102 to the helmet 101, and selects the remote radio unit 102 with the best channel quality as the first remote radio unit for high-speed data transmission;

Step S3: the helmet 101 sends the selected information of the first remote radio unit to the host through a feedback link;

step S4: the wireless virtual reality system is in a normal working state; the host machine completes the generation and rendering of images by using the high-performance video card, and then sends high-definition video and high-fidelity audio to the helmet 101 through the first radio remote unit; the remaining 7 remote radio units 102 not selected by the helmet 101 send channel detection signals to the helmet 101 at preset time intervals in a round-robin manner;

step S5: the helmet 101 receives high-definition video and high-fidelity audio sent by a host through a first radio frequency channel equipped with a high-precision analog-to-digital converter, plays a video signal through a display, and plays an audio signal through an earphone; meanwhile, the helmet 101 sequentially directs the beam to each remote radio unit 102 through a second radio frequency channel equipped with a low-precision analog-to-digital converter and receives a channel detection signal;

Step S6: the helmet 101 continuously updates the channel quality from the helmet 101 to each remote radio unit 102 according to the channel detection signal; meanwhile, the helmet 101 collects feedback information including confirmation information of successful transmission of the video and audio signals, various operation instructions of the handle, user posture information provided by the gyroscope, a gazing direction of the eyes of the user provided by the eyeball tracking sensor and the like, and sends the feedback information to the host through a feedback link;

Step S7: if the helmet 101 finds that the signal quality of the high-speed data transmission link is rapidly reduced, it is determined that an obstacle is encountered, and the process goes to step S8; otherwise go to step S4;

step S8: the helmet 101 selects the radio remote unit 102 with the best channel quality from the remaining 7 radio remote units 102 to determine that the radio remote unit is the first radio remote unit, and feeds back information of the newly selected first radio remote unit to the host through the feedback link;

Step S9: after the host receives the feedback of the helmet 101, the newly selected first remote radio unit belongs to the high-speed data transmission link instead; the radio remote unit originally used for high-speed data transmission belongs to the channel detection link instead.

it should be noted that: the sequence of the embodiments of the present application is only for description, and does not represent the advantages and disadvantages of the embodiments. And specific embodiments thereof have been described above. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing may also be possible or may be advantageous.

the present invention is not intended to be limited to the particular embodiments shown and described, but is to be accorded the widest scope consistent with the principles and novel features herein disclosed.

Claims

1. A wireless virtual reality system based on a distributed antenna is characterized by comprising a host and a helmet;

the host comprises 8 radio remote units which are respectively arranged at 8 top points of a room; wherein 1 of the remote radio units is used for sending high-definition video and high-fidelity audio to the helmet; meanwhile, the other 7 radio remote unit streams send channel detection signals to the helmet.

2. The wireless virtual reality system of claim 1, wherein the host further comprises 1 baseband unit and 1 upper protocol unit;

The 8 remote radio units share the baseband unit and the upper layer protocol unit.

3. the wireless virtual reality system of claim 1, wherein the functions of 3 signal links can be realized, including a high-speed data transmission link, a channel detection link and a feedback link;

The high-speed data transmission link is used for transmitting high-definition video and high-fidelity audio;

The channel detection link is used for sending a channel detection signal;

The feedback link is used for the helmet to feed back information to the host, and the feedback information comprises channel quality, operation commands of a user, signals of various sensors and the like.

4. the wireless virtual reality system of claim 3, wherein the bandwidth of the high-speed data transmission link is an integer multiple of the bandwidth of the channel sounding link, denoted by Q;

The carrier frequencies of the high-speed data transmission link and the channel detection link are the same, and the carrier frequencies are located in a millimeter wave frequency band.

5. the wireless virtual reality system of claim 4, wherein the remote radio unit further comprises an interpolator, a switch, and two shaping filters;

The interpolator is used for repeatedly inserting the value of each data point in the baseband signal into the data stream for Q times;

wherein one of said shaped filters conforms to the bandwidth of said high speed data transmission link and the other of said shaped filters conforms to the bandwidth of said channel sounding link;

The switch is used for switching the two shaping filters.

6. the wireless virtual reality system of claim 1, wherein the helmet employs a hybrid analog/digital beamforming technology; the helmet comprises a first radio frequency channel and a second radio frequency channel, wherein the first radio frequency channel is used for receiving signals of the high-speed data transmission link; the second radio frequency channel is used for receiving signals of the channel detection link;

The remote radio unit adopts an analog beam forming technology.

7. The wireless virtual reality system of claim 6, wherein the helmet's high-speed data transmission link uses a high-precision analog-to-digital converter, and the helmet's channel detection link uses a low-precision analog-to-digital converter;

wherein the precision of the high-precision analog-to-digital converter is at least 4 bits higher than the precision of the low-precision analog-to-digital converter.

8. the wireless virtual reality system of claim 3, wherein the feedback link employs a frequency band below 6 GHz;

The helmet comprises 1 signal transmitting module of a feedback link, wherein the signal transmitting module comprises 1 transmitting antenna;

the host comprises signal receiving modules of 1 feedback link, and the signal receiving modules are positioned in any one of the 8 remote radio units; the signal receiving module comprises 1 receiving antenna.

9. The wireless virtual reality system of claim 1, further comprising a handle connected to the helmet;

The host also comprises a high-performance display card used for generating and rendering images;

the helmet further comprises a display screen, an earphone, a gyroscope and an eyeball tracking sensor.

10. The wireless virtual reality system of claim 1, wherein the workflow of the wireless virtual reality system comprises:

step S1: initializing the wireless virtual reality system; each remote radio unit carries out exhaustive search of the beam direction and records the azimuth angle from the remote radio unit to the helmet; in the horizontal direction, only 90 degrees, namely 1/4 plane, need to be searched; in the vertical direction, only 90 degrees, namely the upper half space or the lower half space, need to be searched; the helmet carries out exhaustive search in the horizontal direction of 360 degrees and the vertical direction of 180 degrees, and records the azimuth angle from the helmet to each remote radio unit;

Step S4: the wireless virtual reality system is in a normal working state; the host machine completes the generation and rendering of images by using a high-performance display card, and then sends the high-definition video and the high-fidelity audio to the helmet through the first radio remote unit; the other 7 radio remote units which are not selected by the helmet send the channel detection signals to the helmet in a turn flow mode at preset time intervals;

Step S5: the helmet receives high-definition video and high-fidelity audio transmitted by the host through a first radio frequency channel provided with a high-precision analog-to-digital converter, and plays video signals through a display and audio signals through an earphone; meanwhile, the helmet sequentially points the wave beam to each radio remote unit through a second radio frequency channel provided with a low-precision analog-to-digital converter and receives a channel detection signal;

Step S6: the helmet continuously updates the channel quality from the helmet to each remote radio unit according to the channel detection signal; meanwhile, the helmet collects feedback information including confirmation information of successful transmission of the video and audio signals, various operation instructions of a handle, user posture information provided by a gyroscope, a gazing direction of eyes of a user and the like provided by an eyeball tracking sensor, and sends the feedback information to the host through a feedback link;

Step S7: if the helmet finds that the signal quality of the high-speed data transmission link is sharply reduced, judging that an obstacle is encountered, and turning to step S8; otherwise, go to step S4;

Step S8: the helmet selects a radio remote unit with the best channel quality from the remaining 7 radio remote units, determines the radio remote unit as the first radio remote unit, and feeds back information of the newly selected first radio remote unit to the host through the feedback link;

step S9: after the host receives the feedback of the helmet, the newly selected first remote radio unit belongs to a high-speed data transmission link instead; the remote radio unit originally used for high-speed data transmission belongs to the channel detection link instead.