Abstract: In a method and apparatus for data transmission and voice signal transmission on a subscriber line, in terminal devices located at least on a network side of the subscriber line, only those parts which evaluate a criterion indicating the beginning of the data transmission are switched into active mode outside the context of data transmission.

Abstract: A time division multiple access communication system is provided having multiple sub-channels according to known quadrature amplitude modulation techniques. Each sub-channel has a pre-determined time duration and is divided by a pre-determined number of symbol position time divisions. The symbol positions carry color codes and ACP codes in addition to sync, pilot and data symbols. Pilot symbols in the second half of the slot are replaced with dual purpose color code and ACP symbols. The dual purpose symbols are either modulated with a lower order modulation than data symbols or are repeated values of dedicated symbols located earlier in the same slot, or both. Slot throughput is attained with a minimal bit error rate penalty.

Abstract: A technique for efficient implementation of pilot signals on a reverse link in a wireless communication system. An access channel is defined for the reverse link such that within each frame, or epoch, a portion is dedicated to sending only pilot symbols. Another portion of the frame is reserved for sending mostly data symbols; however, within this second portion of the frame, additional pilot symbols are interleaved among the data symbols. The pilot symbol or preamble portion of the access channel frame allows for efficient acquisition of the access signal at the base station, while providing a timing reference for determining the effects of multipath fading. In particular, a pilot correlation filter provides a phase estimate from the pilot symbols in the preamble portion, which is then used to decode the data symbols in the payload portion. An access acquisition portion of the receiver uses the phase estimates provided by the pilot correlation filter to process the output of a data symbol correlation filter.

Abstract: A method and apparatus for transmitting broadcast information in a multi-carrier communication system. The Sync Channel of the multi-carrier system is transmitted a 1.25 MHz channel bandwidth (i.e., over a single carrier), and to specify the preferred channels for the Sync Channel transmission instead of the preferred channels for the entire multi-carrier system. The Sync Channel Message will carry additional information indicating the center frequency of a multi-carrier system within a reserved set of frequency bands and indicating the frequency of a single carrier system in the reserved set of frequency bands. Considering the A block of the PCS band again, the preferred channels for Sync Channel transmission can be selected as channels 75, 150 and 225. This selection ensures that one of the preferred channels will always be used by any multi-carrier system regardless of the location of its center channel.

Abstract: A technique for encoding digital communication signals. Data symbols are augmented in pilot symbols inserted at predetermined positions. The pilot augmented sequence is then fed to a deterministic error correction block encoder, such as a turbo product coder, to output a coded sequence. The symbols in the error correction encoded sequence are then rearranged to ensure that the output symbols derived from input pilot symbols are located at regular, predetermined positions. As a result, channel encoding schemes can more easily be used which benefits from power of two length block sizes.

Abstract: Techniques to search for a gated pilot reference in a wireless communication system. In one method, an overall code space in which the pilot may be found is partitioned into a number of groups of code sets, with each code set representative of all possible chip offsets of a specific PN sequence. The groups are ordered based on the likelihood of detecting the pilot in each of the groups. The groups of code sets are then used to search for the pilot, one group at a time, starting with the group most likely to result in successful pilot acquisition and ending with the group least likely to result in successful pilot acquisition. The search is terminated upon successful acquisition. The pilot search may be performed using detect, dwell, and pull-in substages. The detect substage for one group may be performed in parallel with the pull-in substage for another group.

Abstract: A method and apparatus permit information transfer and reception over a communication system that provides the separation of the useful signal from the interference with low BER, independent from it's origin, i.e. whether the interference is orthogonal or non-orthogonal relatively to the useful signal and as a result have a high protectability from the interferences.

Abstract: A searcher receiver (114) includes a sample buffer (202) which stores signal samples loaded using a real time clock. A real time linear sequence generator (RT LSG) (206) stores an initial state and is clocked using the real time clock. The contents of the RT LSG are loaded into a non-real time linear sequence generator (NRT LSG) (208) when sample processing begins. Samples are correlated using a non-real time clock to allow signal processing to be uncoupled from the chip rate. The analog front end (108) may be powered down or tuned to another frequency during non-real time processing.

Abstract: An iterative method involves performing a coarse frequency correction process which adjusts receiver frequency so that a pilot tone signal is within a predetermined frequency range and, after performing the coarse frequency correction process, performing a fine frequency correction process which adjusts receiver frequency so that the pilot tone signal is substantially aligned with a pilot tone reference within the predetermined frequency range. By performing these processes, the receiver frequency may be adjusted so that the alias pilot tone signal is substantially aligned with the pilot tone reference and the pilot tone signal is undesirably shifted outside the predetermined frequency range. To eliminate this condition, the method further involves performing the coarse frequency correction process again and, after performing the coarse frequency correction process again, performing the fine frequency correction process again.

Abstract: A transceiver transmits signals with power control bits, the power control bits instructing the other transceiver to establish selected power levels for its return signal. In one form, a processor is adapted to determine channel coefficients for the pilot symbols as a function of both (1) the selected power levels of the other transceiver signal and (2) the difference between the predetermined pilot symbols and the pilot symbols as received by the receiver. The processor then interpolates channel coefficients for all symbols in the received signals based on the determined pilot symbol channel coefficients. In an alternate form, the processor uses a selected auto-correlation function which takes into account the selected power levels of the other transceiver signal to calculate an interpolation filter. In this alternate form, the processor then uses the calculated interpolation filter and channel coefficients for the pilot symbols to interpolate channel coefficients for symbols between the pilot symbols.

Abstract: There are provided a channel estimation unit for achieving highly accurate channel estimation, a CDMA receiver and a CDMA transceiver with the channel estimation unit. Channel estimates of data symbols are obtained from a pilot symbol sequence which is parallel with a data symbol sequence. First, a plurality of pilot blocks are generated from the pilot symbol sequence. The channel estimates of the data symbols are obtained by calculating a sum of appropriately weighted averages of pilot symbols in the individual pilot blocks. This enables highly accurate channel estimation. More accurate channel estimation can be achieved by carrying out the channel estimation of the data symbols using the pilot symbols belonging to other slots rather than limiting to the pilot symbols in the slot to which the estimated data symbol belongs.

Abstract: A method for transmitting pilot bits instead of partial bits of CQI (Channel Quality Indicator) information indicating channel quality of an HS-PDSCH (High Speed-Physical Downlink Shared CHannel) in a CDMA (Code Division Multiple Access) communication system such that a Node B can control power of a high-speed uplink control channel. The system transmits high-speed packet data from the Node-B to UE (User Equipment) through the HS-PDSCH, and the UE is located in a handover area between the Node-B and another Node-B adjacent thereto. Predetermined bits are then removed from given bits of the code symbols. The removed bits are then replaced with high-speed pilot bits for power control.

Abstract: The pilot signal generation section 103 generates pilot signals in such a way that the pilot signals have a predetermined time-varying pattern on pilot carriers. The pilot signal insertion section 104 allows the pilot carriers to carry only pilot signals. The apparatus on the receiving side carries out channel estimation by correlating the plurality of pilot signals carried on the pilot carriers with the same pattern as that used on the transmitting side. Furthermore, the apparatus on the transmitting side sends pilot signals having a time-varying pattern carried on subcarriers involving DC components which would not be used for information transmission by conventional multicarriers. This makes it possible to improve the transmission efficiency in a radio communication based on a multicarrier modulation system.

Abstract: A method and system for producing a plurality of pilot beacon signals with different carrier frequencies is disclosed. One original pilot beacon signal is first obtained, and a splitter is used to make copies of the pilot beacon signal. Each of the copies are fed into a mixer for generating a plurality of intermediate signals with different frequencies. A bandpass filter is subsequently used to select a final one among the intermediate signals. Thus, a set of pilot beacon signals with different frequencies are successfully obtained.

Abstract: Systems and techniques are disclosed detecting an embedded signal which includes producing a plurality of first correlated values from a portion of the first signal and a second signal, transforming the first correlation values into a plurality of second correlation values related to a frequency content of the first correlation values, and searching for the embedded signal by evaluating the second correlation values. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.

Abstract: The invention is a method for controlling power on multiple forward link communication channels by using multiple power control sub-channels, wherein each power control sub-channel is associated with a forward link communication channel to be power controlled. A fundamental power control sub-channel and a supplemental power control sub-channel are time multiplexed onto a reverse pilot channel. Transmitted over the fundamental power control sub-channel is a fundamental power control bit for indicating to a base station to increase or decrease its transmission power over a corresponding forward fundamental channel. Transmitted over the supplemental power control sub-channel is a supplemental power control bit for indicating to a base station to increase or decrease its transmission power over a corresponding forward supplemental channel. The pilot sub-channels are preferably separated by the fundamental and supplemental power control sub-channels for time diversity purposes.

Abstract: Systems and methods for correcting phase ambiguity in a total pilot phase value are presented. Examples include comparing and correcting total pilot phase values having different pilot frequencies within the same sampling interval, such as the same data symbol. Another example includes correcting a total pilot phase value for one sampling interval and corresponding to one pilot frequency using nonlinear filtering of values of the total pilot phase for prior sampling intervals at the same pilot frequency.

Abstract: The invention provides a method for controlling pilot power within a CDMA system by either conditionally increasing or conditionally decreasing the pilot power of a cell when a transcoder loss per frame of the cell exceeds a threshold value. A cell performance matrix of the cell, and a cluster performance matrix of a cell cluster neighboring the cell are computed when a transcoder loss per frame of the cell exceeds the threshold value. The pilot power is increased when both the cell performance matrix is equal to or greater than the cluster performance matrix and the pilot power is greater than a minimum level. The pilot power is decreased when both the cell performance matrix is less than the cluster performance matrix and the pilot power is less than a maximum level.

Abstract: An apparatus and method for optimizing the transition of a Mobile Station (MS) between states of operation for packet data service. An RF connection is established between the MS and Base Site Equipment (BS) for the transmission of data packets. After a period of inactivity of transmission, the RF connection is released and the BS provides the MS with the equipment identifier of the network element that will maintain the connection with a PDSN. The MS retains the identifier while in the Dormant state and a new Semi-Dormant state and sends the identifier to the BS when requesting reactivation. In the Dormant state, the network element maintaining the connection to the PDSN is the PCF. In the Semi-Dormant state, the network element maintains the connection between to the PDSN is the SDU. When the BS has data to transmit to a MS in the Semi-Dormant state, it channel assigns the MS into the Active state according to pilots reported in RF Measurement Report Messages previously received from the MS.

Abstract: Briefly, in accordance with one embodiment of the invention, a verifier and a method for verifying synchronization of at least one pilot signal pattern of a wireless communication system are disclosed. A method and a module of frequency acquisition are also disclosed.

Abstract: In the CDMA Radio Multiplex Tansmission, transfer function of line is inferred by using common pilot signal and sychronous detection is performed accordingly. The transmitting end transmits by periodically inserting pilot symbols into one channel only of multiplexed channels. The receiving end infers line condition (transfer function) from the received pilot symbols and, on the basis of the information thus obtained, performs synchronous detection of each channel multiplexed.

Abstract: A method and telecommunication system for tracking the carrier phase of a received signal includes the addition of a pilot signal to the data component of the signal prior to modulation and transmission. The pilot signal is specified to have a frequency equal to the inverse of twice a data symbol interval with zero crossings positioned at the midpoint of each symbol interval to avoid interference with the data. The received signal is demodulated to produce a complex data signal from which the pilot signal is detected to provide an estimate of the phase error in the complex data signal. The elimination of the phase error from the complex data signal is accomplished through a corrective phase shift that is equal and opposite to the estimated phase error. A sample timing estimate may also be obtained in a similar manner.

Abstract: A synchronization device for a synchronous digital message transmission system producing a synchronous output signal including successive transport modules synchronized to a frame clock from a digital input signal. The synchronization device includes a receiver unit for receiving the input signal, a packet assembly device for packaging the input signal into subassemblies of the transport modules, a buffer memory, a writer for writing data bits of the input signal out of the subassemblies into the buffer memory with a write clock, a reader, for reading data bits out of the buffer memory with a read clock in order to form the output signal, and a sending unit (SO) for sending synchronous output signals. The effective bit rate of the subassemblies compared to the standardized value is either lowered or raised by selecting the write clock lower than the read clock.

Abstract: Symbol 102 that is spread with the only short spreading code and inserted in synchronism with a long spreading code is specified by detecting the correlation with only the short spreading code. Next, another short spreading code indicative of a timing of reverse and forward link switching is specified, where the short spreading code is multiplexed at the same position as that of the detected symbol. The detection of the symbols spread with only these spreading codes enables to acquire synchronization of the long spreading code, synchronization of switching of reverse and forward links, and synchronization of a transmission frame. It is thereby possible to reduce synchronization acquisition time for the long spreading and an easy planning of base station locations without decreasing the frequency utilization efficiency.

Abstract: A method and apparatus for determining the ratio of gain of a first channel to the gain of a second channel, wherein at least one of the first channel and the second channel is constant over time. The ratio is determined by calculating the quotient of the average, or sum, of the gain of the first channel divided by the average, or sum, respectively, of the gain of the second channel.

Abstract: A multi-carrier transmission system using orthogonal carriers with high order QAM constellations for the transmission of multiple bits per carrier and symbol. Such systems place high demands on the synchronization of the receiver with the transmitter. The maximum permitted deviation from exact synchronization is usually a small fraction of a sampling interval. A reserve carrier, the pilot carrier, which is given a fixed phase, is usually used as the reference to achieve this high accuracy. The receiver sampling clock oscillator is phase locked to the pilot carrier. It is therefore necessary to estimate the phase of the pilot carrier. Using a bandpass filter to recover the pilot carrier, regardless of the frame structure of the DMT signal, does not eliminate the influence of neighboring carriers on the pilot carrier.

Abstract: Despreading means 10 despreads a pilot signal included in a first received signal 1. Strength determination means 15 determines the strength of the despread pilot signal. Integration control means 16 determines the integration interval used by integration means 13, from the strength of the received pilot signal. The differences in strength detected by strength difference detection means 12 are added together by the integration means 13 over the period of time decided by the integration control means 16. The integration interval used by the integration means 13 is made changeable according to the receiving environment. Accordingly, when there is the superior receiving environment, there is reduced the load imposed on the integration means 13 when the integration means 13 performs the processing operations. Therefore, there can be realized a superior CDMA receiver phase tracking system which dissipates a fewer amount of electric power.

Abstract: A circuit coupled to receive a sequence of signals is designed with a multiplication circuit (416, 420) coupled to receive a first signal, a second signal and a complex conjugate of the first signal. The second signal follows the first signal in time. The multiplication circuit produces a first product sequence of the first signal and the complex conjugate and a second product sequence of the second signal and the complex conjugate. A summation circuit (424, 426) is coupled to receive the first product sequence and the second product sequence. The summation circuit produces a first sum of the first product sequence and a second sum of the second product sequence.

Abstract: There is disclosed a packet tunneling method in a mobile data communication network. The packet tunneling method first uses a tunneling protocol to set up tunneling information and uniquely identify a tunnel in a signaling procedure. Then, in a data transmission procedure, the information provided by an addressing mechanism of a packet itself is used to tunnel the packet from one routing node to another with the tunneling information and the uniquely identified tunnel, so as not to use a tunneling protocol in the packet.

Abstract: A technique for encoding digital communication signals. Data symbols are augmented in pilot symbols inserted at predetermined positions. The pilot augmented sequence is then fed to a deterministic error correction block encoder, such as a turbo product coder, to output a coded sequence. The symbols in the error correction encoded sequence are then rearranged to ensure that the output symbols derived from input pilot symbols are located at regular, predetermined positions. As a result, channel encoding schemes can more easily be used which benefits from power of two length block sizes.

Abstract: A method for limiting the peak transmit power in a CDMA communication system including the steps transmitting a first communication signal having a first high transmit power region and transmitting a second communication signal having a second high transmit power region. One of the first and second communication signals is time offset to prevent the first and second high transmit power regions from occurring simultaneously. Time shifting only a portion of one of the first and second communications signals is also taught. The first and second communication signals can also include respective first and second low transmit power regions. The time offset can be selected to align one of the first and second high transmit power regions with one of the first and second low transmit power regions. The total transmit power signal can be determined and the time offset can be selected according to the total transmit power signal to minimize a peak level of the total transmit power signal.

Abstract: For synchronisation purposes, a transmitter (TX) multiplexes a pilot carrier with carriers whereon data elements (DATA) are modulated, and transmits the pilot carrier together with the modulated carriers to a receiver (RX). The immunity of the pilot carrier from interference, such as radio amateur signals, is improved by modulating the pilot carrier with a non-constant signal, for instance a random signal, an alternating signal or even scrambled data elements (DATA), before transmission thereof. Since demodulation of the pilot carrier in the receiver (RX) and averaging successive demodulated pilot carriers reduces the effect of the interference induced on the non-constantly modulated pilot carrier, the degradation of the synchronisation between transmitter (TX) and receiver (RX) is reduced significantly.

Abstract: In the CDMA Radio Multiplex Transmission, transfer function of line is inferred by using common pilot signal and synchronous detection is performed accordingly. The transmitting end transmits by periodically inserting pilot symbols into one channel only of multiplexed channels. The receiving end infers line condition (transfer function) from the received pilot symbols and, on the basis of the information thus obtained, performs synchronous detection of each channel multiplexed.

Abstract: A method to provide information in a communication access network which includes a plurality of terminals (T12, T12, T13, . . . , T31, . . . ) and a head-end (HE). The head-end (HE) includes transceivers (TRX1, TRX2, TRX3, . . . ) and is downstream coupled to each one of the terminals via a downstream common link (Lc) and a tree-like distributive network. Each transceiver provides to a combiner (COMB) included in the head-end (HE) a downstream signal (Sd1, Sd2, Sd3, . . . ) in a frequency band (CH1, CH2, CH3, . . . ) associated to the transceivers (TRX1, TRX2, TRX3, . . . ). The downstream signals (Sd1, Sd2, Sd3, . . . ) are together combined into a downstream modulated signal (S-MOD) which is broadcasted from the head-end (HE) to the terminals. A first one (T12) of the terminals is upstream coupled to a first transceiver (TRX1) via an upstream link.

Abstract: A multi-carrier transmission system using DMT. It is known to recover a receiver sample and clock from a reserved carrier, a pilot carrier having a fixed phase. A sampling clock oscillator in a receiver is then phase locked to the pilot carrier. Multi-carrier receivers, such as DMT receivers, are normally equipped with an FFT processor. A complex number representing the pilot carrier is then available from the FFT processor output. If an FFT processor is not available, a one frequency DFT processor can be provided to produce a complex estimate of the pilot carrier. In a DMT system, frame synchronization is handled separately from sampling clock synchronization, although the two processes are intimately related and frame synchronization must be acquired before sampling clock synchronization.

Abstract: A searcher receiver (114) includes a sample buffer (202) which stores signal samples loaded using a real time clock. A real time linear sequence generator (RT LSG) (206) stores an initial state and is clocked using the real time clock. The contents of the RT LSG are loaded into a non-real time linear sequence generator (NRT LSG) (208) when sample processing begins Samples are correlated using a non-real time clock to allow signal processing to be uncoupled from the chip rate. The analog front end (108) may be powered down or tuned to another frequency during non-real time processing.

Abstract: A method of providing a list of digital control channel (DCCH) frequencies that are in use in a radio telecommunications network to a mobile station operating in the network. Each DCCH includes a superframe having an extended broadcast control channel (E-BCCH) time slot which is broadcast in an E-BCCH cycle. The method begins by dividing the list of DCCH frequencies into a plurality of DCCH subsets, and sequentially or randomly broadcasting the DCCH subsets to the mobile station in the E-BCCH time slot of the DCCH. The next DCCH subset is broadcast when the current E-BCCH cycle is completed. Alternatively, the next DCCH subset may be broadcast when a timer expires. In this case, a broadcast control channel (BCCH) change notification (BCN) indicator is changed whenever a new subset is broadcast.

Abstract: A novel and improved apparatus for a wireless communication device, which provides fast detection and validation of pilot signals while minimizing the probability of false detection. In the apparatus a searcher subsystem generates a pilot energy sample corresponding to a pilot signal, which is provided to a pilot signal detection filter, comprising two parallel branches. The first branch calculates a weighted historical average of a signal strength of the pilot signal in response to the pilot energy sample, the second branch verifies the pilot energy sample in a state machine, wherein transitions of the state machine are proportional to a magnitude of the pilot energy sample. A pilot detection signal is generated if either the weighted historical average exceeds selected threshold, or a state of the state machine exceeds a maximum value of the states.

Abstract: A multi-point communications system is set forth herein. The communications system comprises a transmitter for transmitting OFDM/DMT symbols over a predetermined number of bins across a transmission medium. The OFDM/DMT symbols are generated using at least one timing signal. At least one of the predetermined number of bins includes a pilot tone sub-symbol having a frequency corresponding to the clock signal. The communications system also includes a receiver for receiving the OFDM/DMT symbols from the transmission medium. The receiver demodulates the received symbols using at least one timing signal. The receiver has a first pilot tone search mode of operation in which the receiver adjusts its timing signal to scan the frequency range of the predetermined number of bins looking for the pilot tone sub-symbol and identifies the bin including the pilot tone sub-symbol.

Abstract: The process is characterized in that the pilot signals (10) generated upstream of the device (11) whose non-linearity it is desired to measure pass through a known non-linear device (15) delivering intermodulation products of known characteristics and in that at least one of the known intermodulation products is harnessed in order to modulate, with the aid of synchronous detection circuits (17), at least one of the signals relating to the components of the intermodulation products of the device to be measured.The applications pertain to the analog transmission of television signals over optical fibers.

Abstract: A DS-CDMA transmission method capable of improving the accuracy of channel estimation using pilot symbols by eliminating cross-correlation between pilot symbols inserted into code channels in CDMA multiplexing carrying out fast signal transmission. In each frame assembler, the pilot symbols, which are used for channel estimation for coherent detection, are inserted into coded information data on code channels at fixed intervals, and then the data is modulated by the modulator. The modulated data symbols in each code channel from the modulator are spread by the spreading modulator, the pilot symbols are spread using a spreading code, whereas the information symbols are spread using different spreading codes assigned to respective code channels. The spread signals of the code channels are summed up by the adder to be transmitted.

Abstract: A method and system incorporating the use of interference cancellation during synchronized demodulation of a code division multiple access (CDMA) signal is described. A wireless communications receiver uses synchronized demodulation techniques to estimate the data contained in multiple orthogonal sub-channels of multiple CDMA signals. In response to these estimates an ideal waveform is constructed for each CDMA signal. These ideal waveforms are subtracted from the original signal received to form an interference-cancelled version of the original signal which is used when demodulating individual orthogonal sub-channels.

Abstract: A coherent dual-channel QPSK modulator/demodulator for a CDMA system, and modulating/demodulating methods therefor, are disclosed, in which the crosstalk interferences between an I-channel and a Q-channel are eliminated by an orthogonal spreading method, which assigns different Walsh codes to the I-channel and Q-channel. Pseudo-random modulation and pseudo-random demodulation are carried out by using one PN code so as to minimize the channel parameter estimation errors, thereby improving receiving performance.

Abstract: In a pilot signal detecting method, a pilot signal detecting apparatus, and a receiver, deterioration of communication quality can be prevented in environments where out-of-lock is more likely to occur due to a reduced reception level of a pilot signal. When a demodulator is suffering from out-of-lock with an assigned timing, timings used in respective demodulators are excluded from timing candidates to be newly assigned to the demodulator in the out-of-lock state, such that a timing of a pilot signal, with which a received signal can be demodulated, is selected from the remaining timing candidates.

Abstract: A cell selection scheme in a CDMA mobile communication system which is capable of shortening the cell selection processing time while constructing a mobile communication system with a practically feasible base station configuration. In a CDMA mobile communication system, first type base stations which share a common reference timing are transmitting pilot channels spread by using an identical pilot channel spread code at mutually different spread code phases with respect to the common reference timing where these mutually different spread code phases are assigned to different first type base stations, and second type base stations which do not share the common reference timing are transmitting pilot channels spread by using mutually different pilot channel spread codes at arbitrary spread code phases where these mutually different pilot channel spread codes being assigned to different second type base stations.

Abstract: In a communications network, a network user communicates using a remote unit with another user via at least one base station. The network is comprised of first and second mobile switching control stations respectively controlling communications through a first set of base stations including a first base station and through a second set of base stations including a second base station. To direct communications between the remote unit and the first and second base stations the first base station measures a round trip delay of an active communication signal between the first base station and the remote unit. The remote unit measures a first phase offset of a pilot signal received from a first candidate base station and reports it to the first mobile switching center via the first base station.

Abstract: In a discrete tone system, a base station receives a transmission burst from a remote unit being installed that includes delay compensation pilot tones that are uniformly spread throughout the transmission bandwidth. The arrival time transmission burst is not synchronized with the other remote units transmitting to the base station. The base station measures the phase delay of each tone and calculates the delay of the remote unit from the slope of the line of phase angle versus tone frequency. The base station transmits a signal to the remote unit that includes the magnitude and direction of the delay, which allows the remote unit to adapt the timing of its transmission to be synchronized with the other remote units.

Abstract: In a multi-carrier system, the pilot carrier which is transmitted between two stations for synchronisation purposes, is re-allocated to a new frequency whenever it is disturbed by noise or a single frequency disturber in the vicinity thereof. A less noisy frequency is selected by means of a specific criterion to be fulfilled, for instance based on signal to noise ratio measurements performed for all carriers in the multi-carrier system.

Abstract: A de-spread code phase detection apparatus and method in an SS receiver having a RAKE synthesizing demodulation function of receiving a pilot signal and a data signal, which have undergone spread spectrum modulation, is provided. The apparatus detects a plurality of different de-spread code phases used for demodulation by: performing de-spread processing of the pilot signal, separately performing de-spread demodulation of the data signal by using the plurality of de-spread code phases, performing predetermined weighting processing for the outputs upon phase matching, synthesizing the outputs, and outputting resultant data. The apparatus includes a search correlator, a search processing control section, and a search processing section. The search correlator obtains correlation results of the pilot signal and a de-spread code while sequentially changing the phase of the de-spread code.

Abstract: In a transmission diversity system for selecting one of a plurality of radio transmission systems in a base station to perform diversity transmission of data to a mobile station, the base station adds transmission data and identification signals different in the plurality of radio transmission systems to transmit resultant radio signals from the plurality of radio transmission systems, and transmits transmission data from one radio transmission system based on optimal radio transmission system information transmitted as a radio wave from the mobile station. The mobile station determines an identification signal representing an optimal reception state from the plurality of identification signals detected from the data received from the plurality of radio transmission systems of the base station and transmits the determined optimal radio transmission system information to the base station.