40 results about "Gold code" patented technology

A GPS receiver acquires carrier frequency and Gold code phase using short segments of a received GPS signal. In one embodiment, a 1-ms segment of the GPS signal is transformed to the frequency domain. This is multiplied by a frequency representation of the Gold code. The resulting product is converted to the time domain, and a peak is detected. The location of the peak corresponds to the code phase. If no peak is located, the carrier frequency is changed. Full- and half-bin steps in carrier frequency are considered. Processing gain is achieved by using longer segments of the input signal, for example 4 or 16 ms and integrating 1-ms segments. Considerations are provided for compensating for the effects of a transition, should it occur in the short segment of the GPS signal being processed. Integrations can be performed using non-coherent and coherent techniques. Adjustments are made for non-integral millisecond segment lengths.

Shift code patterns at four continuous phases obtained by dividing 15 shift code patterns given to the respective flip-flops of a linear feedback shift register of degree 4 into four parts are stored in a code memory (11). Besides, mask code patterns to shift a phase of a PN code (PN) to be generated by every four phases, are stored in a code mask memory (12). Next, a logical operation is performed at a phase shift circuit (13) by using the shift code pattern outputted from the code memory (11) and the mask code pattern outputted from the code mask memory (12), to generate a PN code (PN) having a code length of 15 from a random phase.

Shift code patterns at four continuous phases obtained by dividing 15 shift code patterns given to the respective flip-flops of a linear feedback shift register of degree 4 into four parts are stored in a code memory (11). Besides, mask code patterns to shift a phase of a PN code (PN) to be generated by every four phases, are stored in a code mask memory (12). Next, a logical operation is performed at a phase shift circuit (13) by using the shift code pattern outputted from the code memory (11) and the mask code pattern outputted from the code mask memory (12), to generate a PN code (PN) having a code length of 15 from a random phase.

A method for processing positioning signals in a ranging receiver in a stand-alone mode is provided. The method includes collecting pseudorange samples from positioning signals received at the ranging receiver from a plurality of satellites. The pseudorange samples comprise message data modulation. Each satellite has an associated Gold code. A previously determined carrier frequency offset (CFO) is selected from a plurality of directly extracted CFOs. The pseudorange samples are compensated for the selected CFO. The message data modulation is removed from the pseudorange samples. The pseudorange samples are stacked for each satellite. The Gold code associated with each satellite is correlated to generate a pseudorange time sequence for the satellite. A determination is made regarding whether an adequate correlation peak exists in each pseudorange time sequence. A pseudorange is determined for the ranging receiver based on the correlation peaks when an adequate correlation peak exists in each pseudorange time sequence.

A method for processing positioning signals in a ranging receiver in a stand-alone mode is provided. The method includes collecting pseudorange samples from positioning signals received at the ranging receiver from a plurality of satellites. The pseudorange samples comprise message data modulation. Each satellite has an associated Gold code. A previously determined carrier frequency offset (CFO) is selected from a plurality of directly extracted CFOs. The pseudorange samples are compensated for the selected CFO. The message data modulation is removed from the pseudorange samples. The pseudorange samples are stacked for each satellite. The Gold code associated with each satellite is correlated to generate a pseudorange time sequence for the satellite. A determination is made regarding whether an adequate correlation peak exists in each pseudorange time sequence. A pseudorange is determined for the ranging receiver based on the correlation peaks when an adequate correlation peak exists in each pseudorange time sequence.

An EOR (XR11, XR12) of outputs from a plurality of shift stages S1, S2, S4 of an M-series generator 31A is formed, thereby obtaining an M-series which has a desired delay, which in an example is a three bit delay with respect to the output code from the generator 31A. Similarly, outputs from a plurality of shift stages are combined and an EOR thereof is formed to provide another delayed M-series. An EOR of each output from the simultaneously delayed code generator 31 and an output from other M-series generator 32 is formed, thus simultaneously obtaining a plurality of Gold code series.

A pipelined cell search apparatus having a primary search stage, a secondary stage and a Gold code stage. The primary stage receives a primary synchronization channel (P-SCH) signal, detects a maximum peak of a slot boundary in the P-SCH signal, and generates slot timing data from the maximum peak. The secondary search stage receives a secondary synchronization channel (S-SCH) signal and the slot timing data, and detects in the S-SCH signal a maximum peak of a frame boundary. The secondary search stage generates frame timing data and a group ID of a base station transmitting the P-SCH signal and the S-SCH signal. The Gold code search stage receives a common control pilot channel (CPICH) signal, the slot timing data, the frame timing data, and the group ID and detects in the CPICH signal a maximum peak associated with a Gold code of the base station.

A GPS receiver acquires carrier frequency and Gold code phase using short segments of a received GPS signal. In one embodiment, a 1-ms segment of the GPS signal is transformed to the frequency domain. This is multiplied by a frequency representation of the Gold code. The resulting product is converted to the time domain, and a peak is detected. The location of the peak corresponds to the code phase. If no peak is located, the carrier frequency is changed. Full- and half-bin steps in carrier frequency are considered. Processing gain is achieved by using longer segments of the input signal, for example 4 or 16 ms and integrating 1-ms segments. Considerations are provided for compensating for the effects of a transition, should it occur in the short segment of the GPS signal being processed. Integrations can be performed using non-coherent and coherent techniques. Adjustments are made for non-integral millisecond segment lengths.

A GPS receiver acquires carrier frequency and Gold code phase using short segments of a received GPS signal. In one embodiment, a 1-ms segment of the GPS signal is transformed to the frequency domain. This is multiplied by a frequency representation of the Gold code. The resulting product is converted to the time domain, and a peak is detected. The location of the peak corresponds to the code phase. If no peak is located, the carrier frequency is changed. Full- and half-bin steps in carrier frequency are considered. Processing gain is achieved by using longer segments of the input signal, for example 4 or 16 ms and integrating 1-ms segments. Considerations are provided for compensating for the effects of a transition, should it occur in the short segment of the GPS signal being processed. Integrations can be performed using non-coherent and coherent techniques. Adjustments are made for non-integral millisecond segment lengths.

The invention discloses a positioning satellite signal capturing system with high sensitivity. The positioning satellite signal capturing system with the high sensitivity comprises a first digital-controlled oscillator, a half-band filter, a withdrawal device, a memorizer and a correlator, wherein the first digital-controlled oscillator is used for digital downconversion of input signals to enable in-phase orthogonal signals to be generated, the half-band filter is used for filtering high-frequency noise of the in-phase orthogonal signals, the withdrawal device is used for withdrawing filtered signals to reduce the rate of the signals, the memorizer is used for memorizing withdrawn signals, and the correlator is used for extracting signals from the memorizer for related searches. Due to the fact that the correlator is adopted for the related searches, flexible configuration of resources and searching speed is achieved in a searching process, and further the utilization rate of the resources is improved. Different capturing systems can be used only by replacing a gold code generating device and adjusting calculating speed, and therefore compatibility and transportability are good. Furthermore, balance between the resources and the searching speed can be achieved by increasing or decreasing the number of sub-correlators appropriately. The positioning satellite signal capturing system with the high sensitivity is widely used in the satellite communication field.

A method for estimating a scrambling code used on an uplink of a WCDMA system. The scrambling code is obtained from a Gold code, sum of a first specific M-sequence of the user and of a second M-sequence known from the receiver. After sampling of the signal received at the chip frequency of the scrambling code, the successive samples are subject to a differential treatment and the sequence of differential values is multiplied by the second M-sequence. The observables thereby obtained are decoded with the aid of a belief propagation iterative decoding. The decoded values then serve to determine the content of the shift register of the generator of the first M-sequence. One then deduces therefrom the Gold code and an estimation of the scrambling code, Ĉ.

A gold code generator is described comprising two pairs of linear feedback shift registers, the seed values for the second pair of linear feedback shift registers are different from the seed values for the first pair of linear feedback shift registers. The second seed values are calculated from the first seed values. The use of this second pair of linear feedback shift registers prevents the need to use a wide span of taps to the linear feedback shift register to produce output bits. By using two pairs of linear feedback shift registers, a parallel output implementation can be produced in which multiple output bits are produced in a single clock cycle.

A method for acquiring a Gold code, obtained as a sum of a first M-sequence (x) and a second M-sequence (yi), the first M-sequence being generated by a first generator polynomial (gx) and the second M-sequence being generated by a second generator polynomial (gy), the weight of the first generator polynomial being lower than the weight of the second generator polynomial, the acquiring method involving a first step of message passing decoding according to a first bipartite graph the edges of which are determined by the coefficients of the first generator polynomial, a decimation step using a predetermined decimation factor, and a second step of message passing decoding according to a second bipartite graph the edges of which are determined by a third generator polynomial having a minimum weight generating a third M-sequence having the same length as that of the second M-sequence.

A method for acquiring a Gold code, obtained as a sum of a first M-sequence (x) and a second M-sequence (yi), the first M-sequence being generated by a first generator polynomial (gx) and the second M-sequence being generated by a second generator polynomial (gy), the weight of the first generator polynomial being lower than the weight of the second generator polynomial, the acquiring method involving a first step of message passing decoding according to a first bipartite graph the edges of which are determined by the coefficients of the first generator polynomial, a decimation step using a predetermined decimation factor, and a second step of message passing decoding according to a second bipartite graph the edges of which are determined by a third generator polynomial having a minimum weight generating a third M-sequence having the same length as that of the second M-sequence.

The method includes steps: in orthogonal frequency division multiple access (OFDMA) system, when number of usable sub carrier wave is equal to length of inverse discrete Fourier transform (IDFT), Goldcode is adapted as synch sequence directly; when the said number is not equal to the said length, Gold code equal to half length of IDFT is inserted to symmetrical frequency points with, and zeros are inserted to zero frequency points and other frequency points without inserting Gold codes; after being converted to time domain, the sequence is in use as synch sequence; sending the synch sequenceto receiving end from the sending end to establish synch; sending superposed data in OFDMA and synch sequence to the receiving end, or sending data in OFDMA to receiving end directly; using dichotomyat receiving end , the receiving end searches relevant peak value of synch sequence, using estimated carrier deviation compensates phase of received signal so as to obtain data of OFDMA system.

A Chinese-character "Pure gold code" input method features that the encoding parts of Chinese characters are assigned to 27 keys, that is, 26 letter keys plus "["or"]" key and a "Pure gold code" encode rule is used for inputting single words or phrases. Its advantages are easily mastering it and high input speed.

The invention discloses a generation method as well as a positioning method and device of time-division code-division orthogonal frequency division multiplexed signals, and belongs to the field of communication. The method comprises the following steps: receiving a data stream, performing forward error correction coding and OFDM (orthogonal frequency division multiplexing) modulation on the data stream, generating OFDM signals, and generating first spreading codes; getting second spreading codes with the code length which is not less than 511 bits, and superimposing the OFDM signals with a plurality of the second spreading codes to get superimposed OFDM spreading codes; and generating TC (time division and code division)-OFDM signals according to the first spreading codes and the superimposed OFDM spreading codes. According to the method disclosed by the invention, the GOLD codes with the code length which is not less than 511 bits are utilized for correlation integration of a 25ms time slot, the correlation integration result is increased, the cross correlation suppression property of broadcast positioning signals is improved and the positioning precision is improved. Furthermore, through frequency division operation, the property of suppressing cross correlation interference of the generated positioning signals is jointly decided by two factors, the suppression of the cross correlation interference can be well improved.

The invention provides a star topological frame structure, aims at providing a star topological frame structure having certain antijamming capability and being suitable for distributed aircraft networking, a networking process of the star topological frame structure is simple and rapid and the number of the networking nodes for the star topological frame structure is flexible. The star topologicalframe structure is implemented through the following technical scheme: in a network of the star topological frame structure, a transmission timeline between a central node A and noncentral nodes B, C, D and E is divided into a plurality of radio frames RF, each radio frame RF comprises a plurality of resource units RU, the first resource unit RU bears a central node sending waveform, the other resource units RU bear a noncentral node sending waveform; each RU comprises a control time slot composed of a synchronous head, a guiding sequence and a control data area, a service time slot composedof the guiding sequence and a service data area, and a protection interval; BPSK modulation, convolutional encoding and GOLD code spreading are used for the control data area in the control time slot;and QPSK modulation, convolutional encoding and GOLD code spreading are used for the service data area in the service time slot.