750 results about "Antenna diversity" patented technology

An adaptable orthogonal frequency-division multiplexing system (OFDM) that uses a multiple input multiple output (MIMO) to having OFDM signals transmitted either in accordance with time diversity to reducing signal fading or in accordance with spatial diversity to increase the data rate. Sub-carriers are classified for spatial diversity transmission or for time diversity transmission based on the result of a comparison between threshold values and at least one of three criteria. The criteria includes a calculation of a smallest eigen value of a frequency channel response matrix and a smallest element of a diagonal of the matrix and a ratio of the largest and smallest eigen values of the matrix.

Exemplary embodiments of system and method are provided for measuring signal amplitude, phase and / or delay offsets between multiple transmit signals fed through the transmit signal processing chains and wirelessly transmitted over the transceive antennas of separate transceiver modules, wherein transmit signal coupling between the transmit antennas of said transceiver modules' transmit signal processing chains may be used for synchronizing the transmit signals and calibrating their amplitude, phase and / or delay parameters. The exemplary embodiments further provide a front end arrangement of a wireless transceiver device which can comprise at least two independently controllable transceiver modules, each connected to an associated spatial diversity transceive antenna and comprising at least one associated transmit signal processing chain and at least one associated receive signal processing chain coupled to a common baseband processing unit. The exemplary transceiver architecture can be executed on an antenna loop between the transmit signal processing chain of a first transceiver module and the transmit signal processing chain of a second transceiver over the air interface and relies on an adaptive antenna concept which facilitates a wireless transmission of data via a plurality of wireless communication channels utilizing an array of transceive antennas, receiving feedback information via at least one of said communication channels using such antenna loop and modifying a transmission mode based on the received feedback information.

Previous MIMO systems have used spatially diverse antenna elements in order not to reduce the number of orthogonal channels that can be realised. The present invention recognises that this leads to large antenna sizes, as compared to multiple beam antenna systems which use closely spaced antenna elements. In order to provide a compact antenna unit, while still allowing a MIMO system to be exploited, the present invention recognizes that polarization diversity only can be used in a MIMO system without the need for spatially diverse antenna elements. Closely spaced antenna elements are used and this enables a compact MIMO antenna unit to be provided. In addition, such MIMO systems with polarization diversity but no spatial diversity can advantageously be used in line of sight situations and also combined with multi-beam antenna systems to further increase capacity.

Angle of arrival and / or range estimation within a wireless communication device. Appropriate processing of communications received by a wireless communication device is performed to determine the angle of arrival of the communication (e.g., with respect to some coordinate basis of the wireless communication device). Also, appropriate processing of the communications may be performed in accordance with range estimation as performed by the wireless communication device to determine the distance between the transmitting and receiving wireless communication devices. There are two separate modes of packet processing operations that may be performed: (1) when contents of the received packet are known, and (2) when contents of the received packet are unknown. The wireless communication device includes a number of antenna, and a switching mechanism switches from among the various antennae capitalizing on the spatial diversity of the antennae to generate a multi-antenna signal.

An apparatus for transmitting information comprises a bitstream source for providing a bitstream representing the information, a redundancy adding encoder for generating an encoded bitstream, which is arranged to output, for a first number of input bits, a second number of output bits, the second number of output bits having at least twice as many output bits as the first number of input bits, wherein the second number of output bits includes two portions of output bits, each portion of output bits individually allowing the retrieval of information represented by the first number of input bits, and the first portion of output bits being coded based on the bitstream in a different way with respect to the second portion of output bits. The apparatus further comprises a partitioner for partitioning the second number of output bits into the two portions of output bits and a transmitter for transmitting the output bits of the first portion via a first channel and the output bits of the second portion via a second channel, the second channel being spatially different from the first channel. An inventive receiving apparatus combines the signals received via the first and second channels and uses both channel signals for channel decoding by removing redundancy. Thus, the transmitting receiving system is suitable for providing time and / or space diversity and, in the optimal case, provides a C / N value which is greater than 4.3 dB with respect to a two-channel system comprising a duplicator in the transmitter and a channel-controlled switch in the receiver.

A radio-over-fiber (RoF) wireless picocellular system adapted to form an array of substantially non-overlapping individual picocells by operating adjacent picocells at different frequencies is operated to form one or more combined picocells. The combined picocells are formed from two or more neighboring picocells by the central head-end station operating neighboring picocells at a common frequency. Communication between the central head-end station and a client device residing within a combined picocell is enhanced by the availability of two or more transponder antenna systems. Thus, enhanced communication techniques such as antenna diversity, phased-array antenna networks and multiple-input / multiple-output (MIMO) methods can be implemented to provide the system with enhanced performance capability. These techniques are preferably implemented at the central head-end station to avoid having to make substantial changes to the wireless picocellular system infrastructure.

The present invention refers to an antenna diversity system comprising at least a first antenna and a second antenna wherein the first antenna substantially behaves as an electric current source or as a magnetic current source, and the second antenna substantially behaves as an electric current source or as a magnetic current source and a corresponding wireless device. Further the invention relates to an SMT-type slot-antenna component comprising at least one conductive surface or sheet of metal in which the pattern of a slot is created, at least one contact terminal accessible from the exterior of said component to electrically connect the conductive surface included in the slot-antenna component with the ground plane of a circuit board such as a printed circuit board and a corresponding wireless device.

Previous MIMO systems have used spatially diverse antenna elements in order not to reduce the number of orthogonal channels that can be realized. The present invention recognizes that this leads to large antenna sizes, as compared to multiple beam antenna systems which use closely spaced antenna elements. In order to provide a compact antenna unit, while still allowing a MIMO system to be exploited, the present invention recognizes that polarization diversity only can be used in a MIMO system without the need for spatially diverse antenna elements. Closely spaced antenna elements are used and this enables a compact MIMO antenna unit to be provided. In addition, such MIMO systems with polarization diversity but no spatial diversity can advantageously be used in line of sight situations and also combined with multi-beam antenna systems to further increase capacity.

Methods and apparatus for transmitting data via multiple antennas by using antenna diversity. A transmission diversity scheme is established such that two transmission matrices that are in accordance with the space frequency block code combined with Frequency switched transmit diversity (SFBC+FSTD) scheme, are alternatively applied in either the frequency domain, or the time domain, or both of the frequency domain or then time domain. The symbols in the transmission matrices may be transmitted either as one burst in a primary broadcast channel (PBCH), or as discrete bursts in the primary broadcast channel.

A beam forming apparatus and method for forming a plurality of directional beams within a sector, as well as a full sector coverage beam is disclosed, wherein uplink reception diversity is maintained, through provision of a either a single facet antenna or a pair of single facet antennas. Two implementations are disclosed: a first implementation employs orthogonal polarization diversity from a single antenna facet, whereas a second implementation employs space diversity from a pair of spaced apart antenna facets. A first implementation employing polarization diversity comprises an antenna having an array of dipole pairs, dipoles of each pair being positioned orthogonally from each other. The dipole pairs are driven on a downlink, to form a plurality of directional beams having first polarization, and a full sector coverage beam having second polarization. On an uplink, a first plurality of directional beams have first polarity and a second cospatially overlapping set of directional beams have second polarity are formed. A first full sector coverage beam having first polarity spatially overlaps a second full sector beam having second polarity.

The high quality PCS communications are enabled in environments where adjacent PCS service bands operate with out-of-band harmonics that would otherwise interfere with the system's operation. The highly bandwidth-efficient communications method combines a form of time division duplex (TDD), frequency division duplex (FDD), time division multiple access (TDMA), orthogonal frequency division multiplexing (OFDM), spatial diversity, and polarization diversity in various unique combinations. The method provides excellent fade resistance. The method enables changing a user's available bandwidth on demand by assigning additional TDMA slots during the user's session.

A method of performing antenna diversity in a wireless spread spectrum communication system is disclosed. A spread spectrum phase shift keyed (PSK) packet signal having data symbols formed from high rate mode chips is received in each of two respective spaced antenna of a spread spectrum receiver. The bit sync peak sample is determined within the packet signal for each antenna. Predetermined bit sync samples are subtracted a predetermined number of chips on either side of the bit sync peak sample from the peak for each antenna. The antenna having the higher value obtained in the subtracting step accomplished for each antenna is selected.

A transmission antenna diversity method, and a base station apparatus and a mobile station apparatus therefor in a mobile communication system are provided. In the transmission antenna diversity method, channel information is measured from signals received through the plurality of antennas used in the base station, and a channel information matrix is output. The channel information matrix is transformed according to a transform matrix composed of a complex basis vector set. Reception power with respect to the plurality of antennas is calculated based on the transformed channel information matrix. Antenna selection information obtained based on the calculated reception power is transmitted to the base station as feedback information for controlling transmission antenna diversity. Therefore, power is equally distributed to transmitting antennas, excellent performance is maintained at a high speed of movement, and reliable channel adaptation is accomplished at a low speed of movement of the mobile station.

A closed-loop transmitting antenna diversity method, and a base station and mobile station apparatus therefore in a next generation mobile telecommunications system, the closed-loop transmitting antenna diversity method having a plurality of antennas in a mobile telecommunications system, including the steps of (a) measuring the changed amount per unit time of the phase difference between antennas for each of the plurality of antennas which are used in a base station; (b) transmitting the result of measuring as feedback information for adjusting transmitting antenna diversity; (c) receiving and interpreting feedback information in the base station; (d) calculating the weighted value of array antennas for each antenna, using the interpreted feedback information; and (e) multiplying data which is to be transmitted from the base station to a mobile station by the array antenna weighted value, and outputting the result through a corresponding antenna. Here, the changed amount per unit time of the phase difference between antennas is obtained by subtracting the previous phase difference between antennas which the base station knows from the phase difference between antennas which is calculated by a current mobile station.

An object of the present invention is to provide an antenna device which corresponds to a plurality of radio communications systems and frequency bands, which can simultaneously carry out a reception and a transmission of different radio communications systems, and which is capable of using antenna diversity by a simple construction. An antenna device comprises a first antenna (1) matching with first, second, and third frequency bands, a second antenna (2) matching with the third frequency band, a diplexer (3) and the like. For signals of the first frequency band, a high-frequency switch circuit (4) connects a transmitter (8) or a receiver (7) to the diplexer (3) by switching. For signals of the second frequency band, the high-frequency switch (5) connects a receiver (9) or a transmitter (10) to the diplexer (3) by switching. For signals of the third frequency band, the high-frequency switch circuit (5) and a high-frequency switch circuit (6) connect the second antenna (2) or diplexer (3) to a transmitter / receiver (11) by switching.

A method of transmitting a wireless signal (FIGS. 2 and 3A) is disclosed. A data stream (DATA) is received at a first transmitter (210). The data stream is also received by a second transmitter (214) that is remote from the first transmitter. The first transmitter (210) transmits a first part (S1) of the data stream to a remote receiver (220). The second transmitter (214) transmits a second part (S2) of the data stream to the remote receiver (220). The second transmitter (214) is remote from the first transmitter (210).

The present invention allows many of the benefits of spatial diversity to be realized in a hopping radio communications system. One embodiment of the invention includes transmitting signals from a first radio using a first hopping sequence and transmitting signals from a second radio using spatial processing and a second hopping sequence. The second hopping sequence is coordinated with the first hopping sequence. In another embodiment, the invention includes selecting a set of spatial processing parameters based, at least in part, on a determination whether a third radio using a first frequency resource during a first time interval uses a second frequency resource during a second time interval and transmitting a signal from a first radio to a second radio during the second time interval using the second frequency resource and the selected set of spatial processing parameters.

A dual-antenna diversity antenna system that operates within a low frequency band range is disclosed. Two antennas are folded separately onto a single three dimensional dielectric substrate in a meander pattern configuration. Each antenna has an independent feed port and ground pin. The two antennas are configured within a compact mobile terminal to produce high isolation and low correlation at resonating frequencies within the 700 Megahertz frequency band.

A master application device comprises a plurality of distributed transceivers, a central baseband processor, and a network management engine that manages operation of the master application device and end-user application devices. The master application device communicates data streams to the end-user devices utilizing one or more distributed transceivers selected from the plurality of distributed transceivers. The selected distributed transceivers are dynamically configured to switch between spatial diversity mode, frequency diversity mode, multiplexing mode and MIMO mode based on corresponding link quality and propagation environment. Digital signal processing needed for the selected distributed transceivers is performed by the central baseband processor. The network management engine continuously monitors communication environment information to configure beamforming settings and / or antenna arrangement for the selected distributed transceivers. Connection types, communication protocols, and / or transceiver operation modes are determined for the selected distributed transceivers. Resources are allocated to the selected distributed transceivers to continue subsequent data communication.

A method for transmitting a packet of N input bits includes encoding all of the N bits as a single entity, such as with an interleaver of length N within a turbo coder, outputting M encoded bits, channel interleaving the M bits, splitting the M encoded bits into a parallel first and second portion, and transmitting them over separate channels to achieve spatial diversity. The size of the first and second portion is determined based on a closed feedback loop that provides some knowledge of the channel, preferably a measure of channel capacity. The feedback loop may also provide channel knowledge to a subpacket selector associated with each transmit antenna, which determines an appropriate rate for that channel and selects subpackets to fill a transmission packet for that channel. The subpacket selectors choose a subpacket of systematic bits and fill the remaining transmission packet size with subpackets of parity bits. Eigenvectors may be employed to transmit each transmission packet over more than one channel with a power disparity between the channels. A transmitter according to the present invention is also described.

A communication device that comprises a plurality of distributed transceivers, a central processor and a network management engine may be configured based on one or more diversity modes of operations. The diversity modes of operations may comprise a spatial diversity mode, a frequency diversity mode, and / or a polarization diversity mode. Diversity mode configuration may comprise forming, based on selected diversity mode, a plurality of communication modules from the plurality of distributed transceivers, wherein each of the plurality of communication modules may comprise one or more antennas and / or antenna array elements, and one or more of said plurality of distributed transceivers associated with said one or more antennas and / or antenna array elements. The plurality of communication modules may be utilized to concurrently communicate multiple data streams. The multiple data streams may comprise the same data.

The high quality PCS communications are enabled in environments where adjacent PCS service bands operate with out-of-band harmonics that would otherwise interfere with the system's operation. The highly bandwidth-efficient communications method combines a form of time division duplex (TDD), frequency division duplex (FDD), time division multiple access (TDMA), orthogonal frequency division multiplexing (OFDM), spatial diversity, and polarization diversity in various unique combinations. The method provides excellent fade resistance. The method enables changing a user's available bandwidth on demand by assigning additional TDMA slots during the user's session.

A front end circuit for selectively coupling a first antenna and a second antenna to a transmit chain and a receive chain of a radio frequency (RF) transceiver is disclosed. There is a first power amplifier having an input connectible to the transmit chain of the RF transceiver, a first low noise amplifier having an output connectible to the receive chain of the RF transceiver, and a second low noise amplifier with an input connectible to the second antenna, as well as an output connectible to the receive chain of the RF transceiver. A first matching and switch network is connected to the first antenna, the output of the first power amplifier, and the input of the first low noise amplifier. Transmit signals from the first power amplifier and receive signals from the first antenna are selectively passed to the first antenna and the first low noise amplifier.

A method and apparatus for increasing the data rate and providing antenna diversity using multiple transmit antennas is disclosed. A set of bits of a digital signal are used to generate a codeword. Codewords are provided according to a channel code. Delay elements may be provided in antenna output channels, or with suitable code construction delay may be omitted. n signals represent n symbols of a codeword are transmitted with n different transmit antennas. At the receiver MLSE or other decoding is used to decode the noisy received sequence. The parallel transmission and channel coding enables an increase the data rate over previous techniques, and recovery even under fading conditions. The channel coding may be concatenated with error correction codes under appropriate conditions.

A TDD antenna array S-CDMA system for increasing the capacity and quality of a wireless communications is disclosed. By simultaneous exploiting the spatial and code diversities, high performance communications between a plurality of remote terminals and a base station is achieved without sacrificing system flexibility and robustness. The time-division-duplex mode together with the inherent interference immunity of S-CDMA signals allow the spatial diversity to be exploited using simple and robust beamforming rather than demanding nulling. Measurements from an array of receiving antennas at the base station are utilized to estimate spatial signatures, timing offsets, transmission powers and other propagation parameters associated with a plurality of S-CDMA terminals. Such information is then used for system synchronization, downlink beamforming, as well as handoff management. In an examplary embodiment, the aforementioned processing is accomplished with minimum computations, thereby allowing the disclosed system to be applicable to a rapidly varying environment. Among many other inherent benefits of the present invention are large capacity and power efficiency, strong interference / fading resistance, robustness power control, and easy hand-off.

A system and method of data communication uses variable transmit antenna delays based on uplink measurements for the time division duplex (TDD) mode of WCDMA communication. The signals for each channel are delayed at baseband, so different delays can be used for each channel. The delay between each antenna is chosen so that the strongest paths do not overlap in order to implement full transmit antenna diversity. The transmitted signals are detected at a mobile terminal via a joint detector to eliminate noise from other mobile terminals within the cell.

A method and an apparatus for selecting an antenna from an antenna diversity array in a wireless communication system are provided. The method includes the steps of modulating an incoming signal with a spread-spectrum type modulation, measuring a signal quality value for each antenna in the antenna diversity array, and selecting an antenna from the antenna diversity array on the basis of the measured signal quality values. The step of measuring a signal quality value for each antenna may include computing peak-to-average ratio values by dividing a peak sample value by an average sample value, where the average sample value is determined by averaging all of the predetermined number of sample values for each of the plurality of incoming spreading codewords, and the peak sample value is determined by selecting the maximum of all of the predetermined number of sample values for each of the plurality of incoming spreading codewords.

The present invention generally relates to the field of wireless communication systems. It particularly refers to a spatial diversity transmitter (110) and a spatial diversity receiver (120) in a wireless multiple-input multiple-output (MIMO) spatial multiplexing system as well as a corresponding method for wirelessly transmitting and receiving modulated RF signals via multiple wireless signal propagation paths (Pl) of a multipath fading channel in a way that correlation between the MEMO channel components are reduced and / or the signal to interference plus noise ratio (SINR) is increased which hence result in an improved bit error rate (BER) or packet error rate (PER) performance of said wireless MIMO spatial multiplexing system. On the receiver side, for example, this is achieved by controlling at least one antenna switching and / or combining means (121a′+b′) to select a specific combination of different fixed beam antennas (121a+b) from each receiver-resident antenna array. According to the invention, said selection is based on estimated values of the channel impulse responses (hl(τl, t)) for said signal propagation paths (Pl). An antenna beam selection control means (129) is configured for selecting a specific antenna beam combination so as to maximize the average signal-to-interference-plus-noise ratios ( γl) of RF signals (rl(τl, t, φl)) received via said multiple wireless signal propagation paths (Pl) and / or to minimize the correlation coefficients (ρr<sub2>l1< / sub2>r<sub2>l2< / sub2>(t)) indicating the correlations of different pairs of these RF signals (rl1(τl1, t, φl1) and rl2(τl2, t, φl2)).Thereby, each fixed beam antenna (121a+b) of the receiver-resident antenna arrays has a distinct radiation pattern with a different beam center and / or beam width in the azimuth and / or elevation plane, wherein a superposition of all these radiation patterns may cover all possible azimuthal (φ) and / or elevational angles of arrival (θ) of an RF signal (s(t)).For compensating detected multipath fades in the channel amplitude response (|Hl(f, t)|) of at least one signal propagation path (Pl) between the spatial diversity transmitter (110) and the spatial diversity receiver (120), a receiver-resident channel estimation and / or equalization circuitry (124, 128) is applied.