Abstract: Various embodiments are described to provide for the transmission and reception of data in an improved manner. Data transmission is improved by including in a transmitter a null generator (110) to generate an output data symbol sequence that exhibits nulls in the frequency domain at particular frequencies that an input data symbol sequence does not. A pilot inserter (120) then adds a pilot symbol sequence to this output data symbol sequence to create a combined symbol sequence. Since the pilot symbol sequence exhibits pilot signals corresponding to the nulls of the output data symbol sequence in the frequency domain, the combined symbol sequence exhibits pilots that are orthogonal to the data in the frequency domain.

Abstract: A process is disclosed for discriminating between received ranging signals, such as GPS, GNSS, and radar signals, which arrive via a single path and those which arrive via multiple paths. The number of paths is also estimated. This is accomplished by comparing the residual for an ith order ML estimator of signal time of arrival, where order refers to the number of signal paths for which the estimator is optimal, to a discriminant determined either analytically or empirically and deciding that i distinct signal path components are present in the observation of the signal if for all kth order estimators where k<i, the residual is greater than the discriminant for that order estimator and the residual of the ith order estimator is not greater than the discriminant for that order estimator. The invention is particularly useful in obtaining an appropriate signal model for model-based estimation methods.

Abstract: System and method for detecting multiple direct sequence spread spectrum signals using a multi-mode searcher. A preferred embodiment comprises the specification of a hypothesis for a particular communications network. The hypothesis can then be used to generate a pseudo-random number (PN) sequence that is provided to a searcher. The searcher can then make adjustments to the PN sequence to bring the PN sequence to conformity with requirements of the particular communications network. The adjustment to the PN sequence permits the use of a multi-mode searcher to perform searches for signals of various communications networks with minimal hardware dedicated to each communications network.

Abstract: A method for the synchronization of a digital telecommunication receiver comprises the steps of:—storing a plurality of consecutive samples E?1, E, M, L, L+1 of an incoming spread spectrum signal in a delay line 56;—determining by interpolation between consecutive samples of the incoming spread spectrum signal, by means of a first digitally controlled interpolator 26, an interpolated early sample (e) anticipating an optimal sampling time instant;—determining by interpolation between consecutive samples of the incoming spread spectrum signal, by means of a second digitally controlled interpolator 24, an interpolated middle sample (m) corresponding to the optimal sampling time instant;—determining by interpolation between consecutive samples of the incoming spread spectrum signal, by means of a third digitally controlled interpolator 28, an interpolated late sample (l) delayed with respect to the optimal sampling time instant;—calculating an error signal ? as the difference between the energy of the symbols com

Abstract: System for ultra-wideband communications providing high data rates over an extended operating range in the presence of interferers. A preferred embodiment comprises an ultra-wideband (UWB) device that makes use of a portion of the UWB frequency range to help provide good performance in the presence of interferers. Additionally, since only a portion of the UWB frequency range is used, multiple devices can simultaneously transmit and receive by using different portions of the UWB frequency range.

Abstract: Pilot sequences are constructed from distinct “classes” of chirp sequences that have an optimal cross correlation property. Utilization of chirp sequences for pilot sequences results in pilot sequences that have optimal or nearly-optimal cross correlation and auto-correlation properties.

Abstract: There are provided input route selecting means 711-713 and 723-725 for selecting, in accordance with the oversampling phase, input routes along which reception data and codes are to be input to individual shift register means, a plurality of data shift register means 707-710 that are caused by the input route selecting means to operate in groups corresponding to respective oversampling phases, code shift register means 719-722 corresponding to the respective data shift register means 707-710, and despreading integration calculating means 702 and 704. Correlation calculations are performed while reception data are stored in the tap groups efficiently, whereby the search window width is increased when the oversampling setting number is low. Further, the power consumption is reduced by lowering the shift frequency of the shift register means.

Abstract: A receiver for a wireless communication device comprising means for determining a sequence of code block addresses for received rate matched encoded data to allow rate de-matching and decoding to be performed on a code block by code block basis for the received rate matched encoded data.

Abstract: A receiver includes a matched filter matched to a synch pulse and generates a matched filter output signal having peaks and valleys with one of the peaks corresponding to the synch pulse. An orthogonal filter is inversely matched to the synch pulse and generates an orthogonal filter output signal having peaks and valleys with one of the valleys corresponding to the synch pulse. A detector determines the synch pulse based upon a largest difference between the matched filter output signal and the orthogonal filter output signal.

Abstract: A terrestrial C/A code GPS receiver system digitally samples, filters and stores a segment of 11 half chips of the received composite as a binary number and multiplexes this number for parallel correlation with each of a series of multibit code replicas for the satellites to be tracked. Each of the time delay specific correlation products are accumulated in a cell of a memory matrix so that at least twenty two delays for each satellite may be evaluated each code period providing fast reacquisition, even within a city intersection, as well as correction of multipath tracking and multipath interference. All cells of the memory matrix may be used for an acquisition of a single satellite in about 4 ms. Two satellite tracking, in addition to altitude hold, uses cross track hold alternating with clock hold to update the cross track estimate. Single satellite tracking uses cross track and clock hold together. Navigation data is updated with detected changes in motion including turns.

Abstract: A signature sequence is employed in a wireless transmission over a channel and is detected by a receiving station. The signature sequence is selected from a subset of sequences chosen from a set of sequences formed by delay-Doppler shifts of a base sequence. Use of the subset of sequences simplifies detection of the signature sequence by, e.g., facilitating use of a simpler detector structure. A subset of N2 sequences of the specially-constructed delay-Doppler shifted sequence set is selected to facilitate more efficient computation of the detection metric. A simplified detector employs algebraic techniques (such as Discrete Fourier 'Transform (DFT)) that exploit prudent sequence assignment strategy. As an advantageous variation, for a particular class of base sequences that can be represented by segments of equal-length sinusoids, even greater complexity reduction can be achieved by segmenting the delay-Doppler correlation accordingly and reusing past outcome in subsequent overlapping segments.

Abstract: A radio broadcast receiver is provided which reduces the degradation in quality of diversity-received signals. When a difference in level between a reception signal of a main antenna and a reception signal of a sub antenna is less than a predetermined threshold value, and when a difference in phase between the reception signal of the main antenna and the reception signal of the sub antenna exceeds another predetermined threshold value, a combination ratio of a combiner for combining outputs of a main tuner and of a sub tuner is set to 1:1, where in-phase combination type diversity is carried out. In other cases, the combination ratio of the combiner is switched between 1:0 and 0:1 depending on the occurrence of a multipath, where selection diversity is carried out.

Abstract: A RAKE receiver circuit generates combining weights based on channel estimates and combining statistics that comprise channel coefficient statistics, noise statistics, and channel estimation error statistics. Together, these statistics incorporate the relationships in noise and channel estimation across two or more RAKE fingers, and thus improve combining weight generation. Exemplary determination of statistics comprises channel coefficient cross-correlations, noise cross-correlations, and channel estimation error cross-correlations. Determination of the statistics can be varied based on, for example, the assumption of default or nominal signal models.

Abstract: A method for receiving spectrum spreading signals using a Doppler-effect frequency-shift correction generates a corrective signal based on an estimation of a modulation period related to the Doppler effect detected in a preamble portion of a received signal. The corrective signal is used for correcting an information portion of the received signal. Base band digital signals are operated upon by using the DOT and CROSS components.

Abstract: The ultra wide band communication system of the present invention includes a transmitter (station) and a receiver (station). The transmitter and the receiver employ spreading code comprised of code groups, which respectively comprise varied, auto-correlated codes. Consecutive information bits are spread and de-spread with differing code and the code groups are correlated with each other (e.g., orthogonal) so as to reduce channel impulse response estimation noise. At the receiver, subsequent channel estimates can be added or averaged with an initial channel estimate so as to reduce the channel impulse response estimation noise and thereby provide a relatively more accurate channel response.

Abstract: A system and method for synchronizing and selectively addressing multiple receivers in a wireless communication system includes a spread spectrum transmitter and one or more spread spectrum receivers. The transmitter transmits a signal having an observable parameter which is pseudo-randomly varied. The receiver measures the relative times between recurrences of a selected value of the observable parameter being pseudo-randomly varied, and determines an initial state of the transmitter based upon the measured relative times. The receiver then synchronizes itself to the estimated current state of the transmitter using the determined initial state as a starting reference. In a frequency hopping embodiment, the spread spectrum transmitter comprises a feedback shift register, and transmits a sequence of pseudo-randomly hopped frequencies determined by the shift register.

Abstract: The present invention relates to a frequency-hopping analysis circuit of a receiving apparatus in a wireless transmission system, which includes an RF receiving circuit, a detection circuit, and a matching module. The RF receiving circuit receives an RF signal according to an initial frequency-hopping sequence to produce a baseband signal. The detection circuit detects the signal strength of the baseband signal, and identifies the corresponding piconet group of the baseband signal according to the estimated strength. Then, the matching module matches a preamble of the baseband signal according to a plurality of piconets of the corresponding piconet group of the baseband signal, and gives the corresponding piconet of the baseband signal. Thereby, the corresponding frequency-hopping sequence of the baseband signal is given and is transmitted to the RF receiving circuit for replacing the initial frequency-hopping sequence.

Abstract: A radio frequency transmitter is power controlled using a controlling system including an integrating controller, together with an inner and an outer control loop. A tracking signal supplied by the inner loop to the integrating controller of the outer loop is used to avoid windup problems when the transmitted power is saturated.

Abstract: A spread spectrum base station for receiving a plurality of spread spectrum signals and a plurality of phased spread spectrum signals includes an antenna and a plurality of delay devices connected to the antenna, each delay device outputting a time-delayed spread spectrum signal. A combiner is connected to the plurality of delay devices for combining the time-delayed signals and the phased signals, the combiner outputting a combined signal. An RF/IF section is connected to the combiner and converts the combined signal into in-phase (I) components and quadrature-phase (Q) components. A plurality of despreaders are connected to the RF/IF section, each despreader despreading the I and Q components of the combined signal into a despread signal. A controller is connected to each of the despreaders and controls a corresponding delay device.

Abstract: A path protection method for a CDMA reception apparatus is disclosed, which obtains correlation value levels while shifting the despreading timing of reception data little by little, searches for optimal reception timings, outputs a plurality of finger path timings, with respect to the reception data, as reception timings at which reception should be performed, and despreads the respective paths, thereby performing RAKE combining. If all protection paths are in the forward protection state upon execution of path backward protection and forward protection, a protection path with the lowest level is deleted, and a search path having the highest level among paths which are equal to or more than a threshold and detected by a searcher is registered in the deleted portion, thereby allowing assignment of a newly detected path even in the absence of a protection path space.

Abstract: A digital broadcast receiving apparatus for receiving a broadcast signal generated by combining sub signals modulated using a random sequence generated based on an initial value set in accordance with a frequency of a broadcast channel by a signal transmission control use signal and a main signal generated based on information source data and reproducing the information source data contained in the received broadcast signal.

Abstract: Power switches of circuits at respective stages of a low noise amplifier, demodulators, low-pass filers, variable gain amplifiers, and analog-to-digital converters are controlled to be off by an operation control unit in a non-reception period of an impulse signal. An increase in power consumption due to the adoption of an active filter or a variable gain amplifier is compensated for by a reduction in power consumption through intermittent operations of the circuits at the respective stages according to on and off control of the power switches.

Abstract: A system and method is provided for transmitting data signals and additional information signals having partially overlapping frequency bands simultaneously within a wire based communication system over the same wired medium using a spread spectrum technique for modulating the additional information signals.

Abstract: A first network component of an apparatus in one example is coupled with one or more additional network components. The first network component and the one or more additional network components communicate with one another over a single, shared wireline path through employment of a plurality of code division multiple access (CDMA) codes. The plurality of CDMA codes comprise a first CDMA code and a second CDMA code. The first network component sends a first message over the single, shared wireline path to one of the one or more additional network components through employment of the first CDMA code and contemporaneously receives a second message over the single, shared wireline path from one of the one or more additional network components through employment of the second CDMA code.

Abstract: The invention provides methods and apparatus for multiple user detection (MUD) processing that have application, for example, in improving the capacity CDMA and other wireless base stations. One aspect of the invention provides a multiprocessor, multiuser detection system for detecting user transmitted symbols in CDMA short-code spectrum waveforms. A first processing element generates a matrix (hereinafter, “gamma matrix”) that represents a correlation between a short-code associated with one user and those associated with one or more other users. A set of second processing elements generates, e.g., from the gamma matrix, a matrix (hereinafter, “R-matrix”) that represents cross-correlations among user waveforms based on their amplitudes and time lags. A third processing element produces estimates of the user transmitted symbols as a function of the R-matrix.

Abstract: A WLAN (Wireless Local Area Network) receiver is provided that provides at least two acquisition units and at least two tracking units. The acquisition units perform a synchronization acquisition process, and the tracking units perform a synchronization tracking process. The acquisition units are arranged for being operated sequentially while the tracking units are arranged for being operated simultaneously. In an embodiment, frequency and phase error correction may be performed separately, and those units that operate at higher sampling rates may be located before lower-rate units. The synchronization process may include data-aided as well as non data-aided algorithms.

Abstract: In a method and arrangement for detecting a random access channel preamble in a received uplink signal, the uplink signal is received at one or more receive antennas and contains data related to a random access channel preamble. The received uplink signal is subjected to spatial processing and temporal processing in order to detect the random access channel preamble. A best cell portion for communicating with a user may also be determined based on the detected preamble. The best cell portion represents a portion of a cell where a received uplink signal from a user has a highest signal to interference ratio. The detected random access channel preamble is indicative of the best cell portion for communicating with the user.

Abstract: A real-time software receiver that executes on a general purpose processor. The software receiver includes data acquisition and correlator modules that perform, in place of hardware correlation, baseband mixing and PRN code correlation using bit-wise parallelism.

Abstract: An encoder and method for efficient synchronization channel encoding in UTRA TDD mode by: producing a codeword a, where a=dG+z modulo-2, where d represents a predetermined code group to be encoded, G represents a predetermined generator matrix, and z represents a function of the code group number and a row of the generator matrix; producing values sk=2a2k+1+ak;k=0, 1, 2, 3, and associated values b0,b1,b2; and producing a value Sssc associated with the code group, where Sssc=(b0c?(0),b1c?(1),b2c?(2)), c? represents a code within the code group, and b0,b1,b2?(±1,±j). This provides an efficient encoding architecture for the synchronization channel in UTRA TDD mode; and, in addition, by simple manipulation of the generation matrix, a higher chip rate signal may be signalled while still preserving the signalling information for the lower chip rate.

Abstract: Systems and techniques are disclosed wherein a gated pilot signal can be acquired by producing a plurality of product values for each of a first and second signal and a generated signal, coherently combining portions of the product values produced from the first signal and noncoherently combining those coherently combined portions to produce a first value, coherently combining portions of the product values produced from the second signal and noncoherently combining those coherently combined portions to produce a second value, and noncoherently combining the first and second values.

Abstract: A communication system includes a receiver having a variable gain module and a baseband processor. The baseband processor measures the power of the signal received and derives a variable gain control setting that is inversely proportional to the power of that signal and sends the variable gain control setting to the variable gain module. The baseband processor generates a channel quality metric that is equivalent to the normalized geometric mean of the squared magnitudes of the gain estimation, divided by the total noise-plus-interference power.

Abstract: A method and system acquire a received impulse radio signal by first searching, with respect to time, a region of the impulse radio signal using a first template signal to locate a block including a signal cell, and second searching, with respect to time, the block using a second template signal to locate the signal cell to acquire the received impulse radio signal.

Abstract: A spread spectrum meter reading system enables the use of high power frequency hopping spread spectrum (HPSS) transmissions at both the encoder transmitter and repeater levels of the meter reading system. A plurality of end point encoder transmitter devices are each connected to a utility meter and transmit high power FHSS signals containing at least metering data for the corresponding utility meter. A plurality of intermediate transceiver units that are fewer in number than the number of end point encoder transmitter devices both receives and retransmits the high power FHSS signals. A base station includes a receiver that receives the high power FHSS signals. Preferably, the base station can receive the high power FHSS signals from both the encoder transmitter devices and the intermediate transceiver units and the intermediate transceiver units aggregates metering data from multiple encoder transmitter devices prior to block retransmission of the metering data to the base station.

Abstract: A transmitter employing a cryptographic algorithm and key generates and transmits a staggered pulse signal that includes a plurality of high-power pulses that are part of a pseudonoise (PN) code. The high-power pulses are separated by a group of low-power chips and the time interval between the high-power pulses is varied according to the cryptographic algorithm and key. A receiver, employing a corresponding cryptographic algorithm and key receives the signal and correlates it with a locally generated code that is modified according to the cryptographic algorithm and key to detect the phase of the received PN code. The receiver also can include a matched filter configured according to the cryptographic algorithm and key to detect the sequence of high-power pulses in the received signal.

Abstract: A method and system for detecting information relating to the location of a radio IC tag, using an interrogator unit. In one implementation of such method and system, a radio IC tag is securely attached to a fixed object, and a mobile object that has an interrogator unit moves into communication range with the radio IC tag. As the interrogator unit sends radio waves to the radio IC tag, the radio IC tag existing in the communication range sends reflected waves to the interrogator unit. When the interrogator unit receives the reflected waves, it detects and demodulates the reflected waves. The interrogator unit then reads information relating to the location of the radio IC tag as the information stored in the radio IC tag.

Abstract: Errors are reduced when tracing PRNS code delay, especially in receivers operating on signals with rather low code frequency (C/A code) under multibeam effect without deterioration or with minimum deterioration of the signal-to-noise ratio. A method of increasing noise immunity during reception of signals from satellite navigational systems and a device for realizing the same includes radio modules, an analog-to-digital converter, a digital correlation device and digital correlators. A discrimination signal is generated with a variable delay of the signal copy with respect to the exact copy. The use of the correcting sequence of gating digital signals makes it possible to eliminate the multipath effect at a delay of the reflected signal larger than 1.5 d and reduces its negative effect starting from a delay value greater than d/2. In this case, the energy losses compared with a pure mode of the narrow correlator are increased only by 1.76 dB.

Abstract: A communication system for communication with mobile stations through a plurality of base stations at macrodiverse locations and with frequency hopping (FH). Two or more adjacent base stations communicate with mobile stations in a region between the adjacent base stations using coordinated orthogonal frequency hopping sequences. The communication system operates with virtual cells formed of physical sectors from adjacent base stations. Where base stations each operate with three sectors, virtual cells use three adjacent sectors of three adjacent base stations, respectively, and the coordinated orthogonal frequency hopping sequences are used for the adjacent sectors of each of the virtual cells. For GSM, the coordinated orthogonal frequency hopping sequences in each virtual cell are defined by a single hopping sequence number (HSN) and a set of mobile allocation index offsets (MAIOs). Fast macrodiversity switching is employed in combination with FH.

Abstract: A system for detecting and identifying the identity of a base station or cell which transmits a scrambling code is provided. According to one aspect of the system, the system is used to perform scrambling code detection of eight (8) primary cells (each scrambling code being spaced sixteen (16) chips apart) in a group. According to another aspect of the system, a single scrambling code generator is used to generate a master scrambling code. The master scrambling code is then used to create individual scrambling codes which are used in correlation with received signals to detect in parallel which one of the eight (8) possible primary cells in the group transmitted the received signals.

Abstract: A signal that has been received over a first channel is estimated. A set of channels that the signal will be received over is determined. Based on the estimated signal and the set of channels, the signal is removed from a plurality of signals received over a second channel.

Abstract: A low-power sleep mode of operation for a frequency hopping radio receiver is presented. Digital circuits within the receiver operate based upon a high frequency clock source. During sleep mode, the circuits are clocked with a low-frequency clock source, which is typically less accurate in frequency. Periodically, the receiver awakens. The hop sequence channel tuned by the receiver is determined by a mapping based upon the channel upon which the receiver expects to receive communications. The mapping can be changed as necessary to improve tolerance to timing error. Furthermore, once communications are received after a sleep period, the frequency error of the low-frequency clock source can be determined, and compensated for after awakening from subsequent sleep periods.

Abstract: A wireless transmitter (TX1). The transmitter comprises circuitry for providing a plurality of control bits (CONTROL) and circuitry for providing a plurality of user bits (USER). The transmitter further comprises circuitry (16) for modulating the plurality of control bits and the plurality of user bits into a stream of complex symbols and circuitry (18) for converting the stream of complex symbols into a parallel plurality of complex symbol streams. The transmitter further comprises circuitry (20) for performing an inverse fast Fourier transform on the parallel plurality of complex symbol streams to form a parallel plurality of OFDM symbols and circuitry (22) for converting the parallel plurality of OFDM symbols into a serial stream of OFDM symbols. The serial stream consists of an integer N+1 OFDM symbols. Each OFDM symbol in the serial stream of OFDM symbols comprises a plurality of data points. Finally, selected OFDM symbols (SF1.

Abstract: Several techniques are provided for use by wireless devices to avoid interference with signals that are of a periodic or quasi-periodic nature that may operate in the same frequency band and proximity. In some cases, the periodic signals are detected and their timing is determined so as to predict when a next interfering event will occur. Devices that are affected by the periodic signal (such as an affected device with information to be transmitted or devices that have information to be transmitted to the affected device) are controlled to prevent transmissions during the interfering intervals. In addition, a process is provided to dynamically fragment a transmit frame of information to transmit part of the information before the interfering interval and the remainder of the information after the interfering interval, rather than waiting to transmit the entire frame until after the interfering interval.

Abstract: The present invention provides a method and a device in which two or more fingers of a RAKE receiver can locked to a multipath received signal in a situation of a fat finger impulse response. One embodiment of the present invention assigns two RAKE fingers to an impulse response so that one finger tracks the impulse response with an Early-Ontime DLL method and the other finger is tracking the impulse response with an Ontime-Late DLL method. The method comprises detecting the delay between the received signal and a delayed version, comparing the delay with a pre-determined threshold and when the delay falls below the threshold, changing the tracking method of the delayed version of the received signal to a second tracking method.

Abstract: Components and method are provided to efficiently process wireless communications data where prior knowledge of the specific format of the communication data is not available. A wireless transmit receive unit (WTRU) is configured for use in a wireless communication system where communication data for selected channels is transmitted in system time frames in formats selected from among a set of predefined formats. The WTRU has a receiver, a memory, a received chip rate processor (RCRP), a format detector and a de-interleaver. The RCRP is preferably configured to despread each wireless signal of spread data received in each time frame using a minimum spreading code or other appropriate key sequence and to store resultant despread data for each respective time frame in the memory. The format detector is preferably configured to determine the number of physical channels and the respective spreading factor for each physical channel for the wireless signal of spread data received in each time frame.

Abstract: This invention is a multiple access communication technique by which a multitude of transmitters communicate with receivers using direct sequence spread spectrum signaling. The direct sequence codes are reused by a large number of simultaneous transmitters, so the system is named Code Reuse Multiple Access (“CRMA”). This reuse method requires only a small number of codes relative to the number of simultaneous transmitters, and can use as few as one code for all the users. The direct sequence codes are not required to have special properties such as maximal length. The lengths of the spreading codes employed are not necessarily related to the bit or symbol interval. CRMA can be implemented on a Paired Carrier Multiple Access (“PCMA”) system with or without a novel receiver structure which is also described.

Abstract: A base station apparatus for controlling power of individual control information transmitted to mobile stations. A first mobile station receives its own control information, and a second mobile station receives its own control information and control information for the first mobile station. A receiver receives information on forward channel conditions of the mobile stations for a previous time period. A channel transmitter transmits individual control information to the first mobile station and the second mobile station for a preset time period. A required transmission power calculator calculates power levels required for transmitting control information to each of the mobile stations for the preset time period taking into consideration the forward channel condition of each of the mobile stations and transmission power used for transmitting control information to each of the mobile stations for the previous time period.

Abstract: A method and system for synchronizing the PN phase of a pseudo-noise (PN) coded signal with a phase of a master PN decade-code is provided. The method includes the steps of associating the master PN decade-code initialization t0 with a first time zone reference date and time and determining an elapsed time t1. The next steps equate the elapsed time t1 to a corresponding phase of the master PN code and synchronize the phase of the PN coded signal with the corresponding phase of the master PN decade-code.

Abstract: A method for controlling antennas of a receiving device in a radio system, especially in a mobile radio system, in which at least one change is made using a frequency hopping method between a number of transmission frequencies that are provided for the transmission of radio signals. A table is formed with data relating to the reception quality of each antenna. This data is evaluated on each change to the transmission frequency, and one of the antennas is selected as a function of the result of the evaluation. The method is especially suitable for use in systems using slow frequency hopping methods (slow frequency hopping systems), such as bluetooth or WDCT systems.

Abstract: A communication system for communication with mobile stations through a plurality of base stations at macrodiverse locations and with frequency hopping (FH). Two or more adjacent base stations communicate with mobile stations in a region between the adjacent base stations using coordinated orthogonal frequency hopping sequences. The communication system operates with virtual cells formed of physical sectors from adjacent base stations. Where base stations each operate with three sectors, virtual cells use three adjacent sectors of three adjacent base stations, respectively, and the coordinated orthogonal frequency hopping sequences are used for the adjacent sectors of each of the virtual cells. For GSM, the coordinated orthogonal frequency hopping sequences in each virtual cell are defined by a single hopping sequence number (HSN) and a set of mobile allocation index offsets (MAIOs). Fast macrodiversity switching is employed in combination with FH.

Abstract: There is disclosed a method for performing channel assignment in a base station for a mobile communication system. Upon receipt of a request for assigning a channel to a mobile station, a base station transceiver system (BTS) generates a connect message including channel information, which indicates a Walsh code, out of 256 Walsh codes, to be used for a channel to be assigned to the mobile station, and a quasi-orthogonal function (QOF) index. The BTS transmits the generated connect message to a base station controller (BSC). The BSC generates a connect ACK message for acknowledging the channel assignment-related information included in the connect message and transmits the generated connect ACK message to the BTS. Upon receipt of the connect ACK message, in the BTS assigns the channel that was acknowledged by the BSC to the mobile station.