[0033] The present invention proposes a new wireless solution for home Internet access. figure 1 The architecture of the home station of the present invention is shown. In this manual, TD-SCDMA air interface is taken as an example to illustrate. However, the present invention can also be used for other air interface technologies like LTE TDD, WCDMA, WiMAX etc. that can provide broadband access.
[0034] exist figure 1 Among them, TD-SCDMA (1.28Mcps TDD) is used as the backhaul for external data transmission. All data received from and transmitted to WLAN, voice and LAN is routed via the TD-SCDMA air interface. In the downlink, the Ethernet switch receives data from the network side through the TD-SCDMA user end module, and then sends the received data to the correct port according to the MAC physical address. In the uplink, the Ethernet switch forwards the data received from the WiFi access point (AP) and/or the LAN port to the network side. Through Ethernet switch, TDD WBA home station can also support local data exchange between users from WiFi access point and from LAN port.
[0035] Since the TDD air interface is the bottleneck of data transmission, for the uplink (data routing from WiFi/LAN to the external network), a processing module including memory and processor is added between the TD-SCDMA UE module and the Ethernet switch .
[0036] The processor is used to support home service applications, such as IMS applications, data packet transmission conversion, and uplink data scheduling. These applications can be implemented in the processor in the form of software modules. In order to solve the problem of uplink transmission congestion, the processor can schedule the data to be transmitted based on various algorithms: based on data priority (such as the IP priority field included in the IP packet, that is, with High-priority packet data will be sent to TD-SCDMA module for sending first); based on round robin scheme (that is, data from different source IP addresses are forwarded to TD module for sending one by one), or the The processor sequentially transfers the incoming data.
[0037] On the uplink side, the data received from the Ethernet switch should be sent to the memory first. These data are queued in the memory, for example, according to priority; or these data are sequentially sent into the memory, and then sequentially taken out from the memory. The processor requests the TD-SCDMA module to take out the scheduled data in the memory according to the scheduling algorithm. For example, if the scheduling algorithm is based on data priority, and the data in the memory is also organized as a priority queue, the processor controls the TD-SCDMA module to fetch the data with the highest priority for transmission.
[0038] The communication between the TDD WBA home station and the TDD network is based on the 3GPP standard. In order to have better performance, R5 (supporting HSDPA) and later versions (including R8, LTE) are proposed.
[0039] The TDD WBA home station works in the mobile communication system, but in fact, this kind of home station is not a mobile terminal, but a fixed access terminal.
[0040] Assume that the system side knows that the user is a home station user. This can be achieved by something like an ID incorporated into the Home Subscriber Server (HSS).
[0041]Usually in TD-SCDMA system or any other system using smart antenna technology, the network (base station BS) side selects predefined antenna weights or generates groups of antenna weights to maximize uplink received signal strength. Then, when the network (base station BS) sends data to the UE in the downlink, the selected or generated weighting set will be used to direct the downlink beam towards the receiving UE. This process is done continuously in each time slot used by the UE, thus enabling the network side to always keep up with the location of the UE, thereby improving the received signal-to-noise ratio (SNR) in uplink and downlink.
[0042] But for home stations that are not moving, it no longer makes sense to periodically generate and adjust beams. Once the location of the UE is found, the network can always use the fixed set of antenna weights optimized to the location of the UE to receive uplink signals and also use this fixed set of antenna weights to transmit downlink data.
[0043] To achieve this, the following reference figure 2 The flow chart is used to explain the detailed process of TDD WBA home station to realize home wireless access in mobile communication system:
[0044] 1. The network side finds that the user is not an ordinary mobile phone, but a stationary home station.
[0045] 2. Antenna weight group generation: when the base station discovers that the HBS enters the network for the first time, the network side can use traditional methods to generate antenna weights.
[0046] 3. In order to avoid incorrect UE direction estimation, this process can be repeated for several time slots and then fixed antenna weighting. For example, the system has defined many groups of weights, and these weight groups respectively correspond to beams pointing in different directions. In this case, the base station at the network side can calculate which set of predefined weights is used for the best system performance, and thus select this set of weights. Specifically, if the GOB (Grid of beamforming) method is used, it is assumed that the weighted group selection process is performed continuously M times, and then the weighted groups selected more than M/2 times are used. If no weighted group is selected more than M/2 times, the weighted group selection process is repeated until there is a weighted group that satisfies the condition of being selected more than M/2 times. If not GOB, the antenna weights are repeatedly generated in M slots, and then averaged during these M times.
[0047] As an alternative to step 3 above, the network side can also first estimate the location of the home node by other means like A-GPS (Assisted Global Positioning System), and then use the antenna weighting set optimized to that direction.
[0048] 4. The base station on the network side stores the generated antenna weighting group. And in subsequent communications, the network side directly uses the generated weights in uplink reception and downlink transmission without further weight generation process.
[0049] 5. When the base station detects that the HMS is not synchronized, the base station can update the weighted group, which helps to solve the problem that the HMS in the network loses synchronization with the network due to its movement under certain circumstances.
[0050] As an alternative to step 5, the base station may set a timer for periodic weight updating. This period can be set to be long enough, such as one day or one week.
[0051] image 3 It is shown that UE1, UE2 and UE3 are home stations. These home stations will use fixed beams instead of dynamically adjusting according to the actual location of the user terminal.
[0052] If the users are in different directions, i.e. using different beams, the same Orthogonal Variable Spreading Factor (OVSF) code can be used in the same time slot and carrier, a concept known as Space Division Multiple Access ( SDMA). In the traditional TD-SCDMA system, since the user end may move back and forth, it is not easy to make this SDMA work effectively. And especially when the number of UEs in a cell is high, spreading code reuse does not make sense.
[0053] However, since the home station does not move, the problem becomes simple. The network does not need to continuously monitor the direction of each user end to dynamically allocate spreading codes to realize the multiplexing of spreading codes, as in the mobile case.
[0054] More specifically, for a TD-SCDMA system that supports both stationary HBSs and ordinary mobile phones, fixed resources (ie, combinations of time slots, carriers, and spreading codes) can be reserved or allocated for all HBS users. This makes it possible to distinguish between mobile subscribers and home stations and to reduce system complexity. The network then estimates the direction of each home station if any of the two users are in a different direction, such as image 3 As shown, all spreading codes can be reused.
[0055] The network knows through methods like angle of arrival (AOA) measurement that UE1, UE2 and UE3 (UE1, UE2 and UE3 are home stations) are in different directions, and then UE1, UE2 and UE End UE3 can reuse all allocated spreading codes.
[0056] By utilizing this scheme, the system capacity can be improved to a great extent.
[0057] Since the HMS does not move, there is no need to frequently perform cell update, cell selection, and synchronization shift adjustment.
[0058] If the home station is not synchronized with the network, the conventional synchronization procedure defined in the 3GPP standard will be invoked automatically. Or the home station can reboot the system to trigger another network access procedure to obtain a connection to the network.
[0059] Since the home station does not move, the switching-related measurements on the network side and the terminal side are no longer meaningful, and these functions can be discarded. However, ISCP measurements are still necessary to ensure that, through intra-cell switching (TS changes), the home station always works in the best time slot.
[0060] For the HSDPA business, the network dispatches home station users according to its subscription information in terms of user data rate. The network schedules the home station users so that the users get the average data rate of the subscription value. This can bring users a high-speed experience similar to xDSL.
[0061] This depends on the implementation of the scheduling algorithm of the processor on the network side (base station). The processor works as follows: assume that the signed data rate is S, and the current average data rate is M (averaged over all valid sending times, where the user data queue memory is not empty); if M
[0062] Although the invention has been described above with reference to the examples shown in the accompanying drawings, it is obvious that the invention is not restricted thereto but can be modified in various ways within the scope disclosed in the appended claims.
