Shanghai, China
Shanghai, China

Spreadtrum Communications, Inc. is a fabless semiconductor company headquartered in Shanghai, China which produces chipsets for mobile phones. It is the world's 17th-largest fabless semiconductor company measured by 2011 revenues.The company originally produced chips for GSM handsets, but most of its resources are now focused on the Chinese TD-SCDMA 3G standard. In addition to GSM and combined GSM/TD-SCDMA baseband chipsets, Spreadtrum also supplies chips for two Chinese mobile TV standards: TD-MBMS and CMMB. Spreadtrum's customers accounted for 50% of TD-SCDMA handset sales in China Mobile's current round of TD-SCDMA trials.In June 2008 the company's stock had fallen to a 52 week low owing to stalled sales, Later, the stock has increased steadily, reaching an all-time high in November 2011.Spreadtrum agreed an acquisition by Tsinghua Unigroup in July 2013 for about $1.78 billion; the deal completed on 23 December 2013. Wikipedia.


Time filter

Source Type

First and second inputs are received. The first input indicates a frequency offset of a frequency band allocated for signal transmission. The said allocated band is a subband of a total band available for transmission. The second input indicates a bandwidth of the allocated band. One or more filters of a transmitter of a communications system are controlled to operate cumulatively in a lowpass filtering mode, wherein the highest frequency in a pass band in the lowpass filtering mode is less than the highest frequency of the total band available for transmission. A signal is filtered using the filter(s).


Patent
Spreadtrum Communications | Date: 2015-03-11

The present invention discloses a method of mobile terminal internal communications, which belongs to the field of mobile communications. The method comprises: a control signal channel is connected within an application processor module and a baseband processor module, and the control signal channel is composed of a first signal channel, a second signal channel and a feedback channel. A first request signal is sent from the application processor module to the baseband processor module via the first signal channel, and then a feedback is sent from the baseband processor module to the application processor module via the feedback channel. After the feedback is sent to the application processor module, the application processor module starts to send data to the baseband processor module. A second request signal is sent from the baseband processor module to the application processor module, and then the baseband processor module starts to send data to the application processor module.


Patent
Spreadtrum Communications | Date: 2015-04-02

Method and apparatus for controlling a physical layer protocol data unit (PPDU) transmission rate of a physical layer in a first terminal are provided. The method includes: obtaining a media access control protocol data unit (MPDU) retransmission frequency of the first terminal in a first period, where the first terminal is a station or an access point in a wireless network; if the MPDU retransmission frequency is less than a frequency threshold, promoting the PPDU transmission rate in a second period; and else, suppressing the PPDU transmission rate in the second period, where the second period is following and adjacent to the first period along a time axis. The PPDU transmission rate may be adjusted adaptively according to a channels practical transmission state, the physical layer rate may be prevented from decreasing continuously in noisy channel environment, and a throughput rate may be improved in real time.


Method and apparatus for controlling startup of RTS/CTS mechanism is provided. The method includes: obtaining a noisy level of a channel based on the number of first data received by a first terminal in a first period, where the first terminal is a STA or an AP in a wireless network, and the first data include aggregation frames or non-aggregation frames; and if the noisy level is greater than or equal to a noisy level threshold, controlling the first terminal to start up the RTS/CTS mechanism when data is transmitted in a second period which is following and adjacent to the first period along a time axis. The noisy level of the channel may be obtained in real time, and the RTS/CTS mechanism may be controlled to be started up reasonably in real time, so that channel resources is utilized sufficiently, and a throughput rate is improved.


Method and apparatus for controlling length of aggregation frames in a wireless network is provided. The method includes: obtaining a noisy level of a channel based on the number of first data received by a first terminal in a first period, the first terminal being a STA or AP in the wireless network, and the first data include aggregation frames or non-aggregation frames; and determining length of an aggregation frame to be transmitted by the first terminal in a second period based on the noisy level, where the second period is following and adjacent to the first period along a time axis. The first terminal may detect the noisy level and select the length of the aggregation frame based on the noisy level. Thus, inter-frame collision and interference in the channel may be reduced, channel resources may be well utilized, and a throughput rate may be improved in real time.


Patent
Spreadtrum Communications | Date: 2015-04-02

Method and apparatus for controlling CCA threshold of a wireless communication channel is provided. The method includes: obtaining a noisy level of the channel based on the number of first data received by a first terminal in a first period, the first terminal being a STA or AP in a wireless network, and the first data include aggregation frames or non-aggregation frames; and adjusting the CCA threshold the first terminal uses in data transmission in a second period based on the noisy level. The first terminal may adaptively detect the noisy level of the channel, and the CCA threshold may be selected reasonably based on the noisy level, which enables the first terminal to obtain an opportunity of accessing the channel in time when it needs to send data, enhance the first terminals competition ability of occupying channels, and improve a throughput rate.


A slow-clock calibration method, a slow-clock calibration unit, a clock circuit and a mobile communication terminal are provided. The calibration method includes: obtaining a current temperature of the crystal; searching a unique frequency-divide coefficient corresponding to the current temperature from a preset data base; if the coefficient is found in the data base, inputting the unique coefficient into a frequency divider; if the coefficient is not found in the data base, obtaining an actual sleep length of the mobile communication terminal, if the actual sleep length is not equal to a required sleep length, calculating a required frequency-divide coefficient and updating the data base with the required frequency-divide coefficient, and if the actual sleep length of the mobile communication terminal is equal to the required sleep length, updating the data base with a current frequency-divide coefficient. Accordingly, slow-clock calibration is realized with reduced crystal costs.


A method for searching network at startup, a Communication Processor (CP) and a terminal equipment are provided. The method includes: after the CP is powered on and initialized, determining characteristic information of networks supported by the CP; searching for available networks according to the network characteristic information, and obtaining available network information; and obtaining a network searching instruction transmitted from an Application Processor (AP), and determining a network searching result according to the available network information. The method reduces the time for searching network at startup.


A signal amplifying device and methods for control a signal amplifying device and for identifying a signal amplifying device are provided. The device includes: a baseband module, a user identification module interface, return side RF modules and antennas, access side RF modules and antennas. The return side antenna receives a downlink signal, which is transmitted to a corresponding access side RF module and the baseband module. An uplink signal is received by the access side antenna, which is transmitted to a corresponding return side RF module and the baseband module. The baseband module is adapted to process the uplink/downlink signal, control synchronization of the return side RF module and the access side RF module and control turning on and off of the same, read a user information. Accordingly, a cellular network can control a micro-power repeater effectively, and further more functionality can be added and performance can be improved.


Patent
Spreadtrum Communications | Date: 2015-10-07

A latch and a frequency divider are provided. The latch includes: a first logic unit coupled between a power supply and a ground wire, wherein the first logic unit includes a first input terminal and a first output terminal; a second logic unit having a structure symmetrical to that of the first logic unit, wherein the second logic unit includes a second input terminal and a second output terminal; and a first feedforward control unit adapted for cutting off a first current path, wherein the first feedforward control unit includes a first clock signal input terminal adapted for receiving a first clock signal, a third output terminal coupled to the first output terminal, and at least two feedforward control terminals, at least one of which is coupled to the first input terminal or the second input terminal. Power consumption of the latch and the frequency divider can be reduced.

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