Abstract: A cognitive radio signal processing method suitable for single receiver devices where interference is mitigated using projection of received multi-dimensional signal space to maximize SNR by orthogonalizing interference is described. The method is based on a well-known LMS solution that is computed from received multi antenna and multicarrier signals in a novel way. This method solves the requirement of multiple RF chains in low cost handsets by introducing a protocol synchronous antenna switcher that allows, for example, a LTE handset with a single antenna to benefit from algorithms that typically require multiple receivers for the same frequency, i.e. MIMO.

Abstract: A method that allows for rapid inter base station handoffs in IP based wireless networks is disclosed. More specifically a technique to address the problem of accurate location management during rapid handoff across multiple base stations is described in this invention disclosure. The idea proposed uses a combination of Timestamp and Sequence number along with a message exchange protocol over the network to maintain the registration with only a single base station at any point of time.

Abstract: A cognitive radio transmission control system that controls the physical layer protocol based on algorithm feedback from receivers is disclosed.

Abstract: A cognitive MANET system is disclosed that uses TDD (Time Division Duplexing) and TDMA MAC to maintain routes that allow delivery of adequate bandwidth for applications resulting in an efficient way of maintaining information on neighboring wireless terminals and access points by using a routing protocol that has a built in slot reservation algorithm.

Abstract: A Radio Frequency (RF) splitter/combiner technique for splitting and combining RF signals using a combination of microstrip traces and coaxial cable for an N-port network is disclosed.

Abstract: The invention disclosed in this application describes methods to coordinate spectrum measurement periods in access points or base stations in a time division duplex (TDD) system where the super frame is divided into uplink and downlink portions for use in cognitive radio systems.

Abstract: A mechanism is disclosed where a Base Station provides assistance to a mobile device in the channel-switch process because a mobile device might have to perform frequent channel switches to overcome adverse channel conditions due to interference in the 900 MHz ISM band. The Base Station broadcasts channel-specific information that will be used by all mobile devices to accurately select prospective channels for future channel-switches, thereby cutting down the latency that is experienced during an actual switch.

Abstract: In wireless networks where multiple base stations are deployed, handsets may handoff from one base station to the other while in a voice call. In this disclosure a layer-2 hand-off mechanism for cellular systems designed to operate in unlicensed spectrum is described. More specifically a proposed method that does not use any pre-determined thresholds to initiate the hand-offs is disclosed.

Abstract: The invention disclosed in this application describes an error detection method that can be used to identify an OFDM symbol that is interfered with. The method is based on computing a symbol by symbol path error metric from error correction code and by comparing the statistics of each individual symbol to the mean and the variance of the metric computed from the whole data packet.

Abstract: The invention disclosed in this application describes a diversity combiner that operates as a maximal ratio combiner (MRC) when no interference is detected and as a selection combiner when OFDM symbol errors are detected with high probability.

Abstract: This invention describes a cognitive radio receiver architecture where multiple specialized receiver algorithms are executed in parallel. For example, maximal ratio combiner and beam forming algorithms may be running parallel. The receiver system computes solutions using different hypotheses of channel conditions and chooses the best result, i.e. is able to decode data from one of the parallel receivers.

Abstract: This invention describes a cognitive radio signal processing where interference is mitigated using multiple frequency spatial projection to orthogonalize interference. The method is based on the well-known LMS solution of W=(ATA)?1*d that is computed from received multi antenna and multicarrier signals in a novel way.

Abstract: This invention describes a hardware and software architecture for concurrent dual-band or multi-band operation. More specifically this invention describes a multi-band cognitive radio network that allows terminals to efficiently use signal processing and RF resources by synchronizing the framing in multiple frequency bands. The invention is useful in TDMA systems by allowing efficient use of signal processing resources.

Abstract: This invention addresses a method of scanning and self organization that is programmed into the base station which then will automatically avoid mutual interference and move the use of radio channels from one base station to another to move network capacity to where it is needed through a process called “abandonment”.

Abstract: This invention addresses a method of whereby a cellular base station can scan the radio band to identify radio channels that are not in use, then claim those un-used radio channels for use to transmit and receive radio signals. A plurality of such radio base station could then comprise a cellular radio network, which channel planning and frequency re-use has become autonomous and self organizing. The present disclosure aims to further expand the utility and function of such self organizing cellular networks by including a user interface to the base station by which the operator can define the radio spectrum boundaries that the base station is authorized to operate within and to further set operational rules for the use of sub-sections of that defined spectral boundary.

Abstract: This disclosure describes a new keep alive timeslots based method to track registered handsets for a MAC protocol that combines contention-free and contention-based MAC protocols into a heterogeneous MAC protocol used for forwarding VoIP traffic in VoIP systems on wireless networks using multiple base stations thus allowing for transmission of high bit-rate data to multiple users over wired and wireless means.

Abstract: A system and method for substantially reducing average transmit power by omitting the transmission of a majority of pulses by using a modified run length coding to reduce signal power. By lowering the average power, an opportunity is presented to either decrease the total power drawn by the transmitter (battery life) or raise the peak power of all symbols (Eb/No), thereby increasing range of a RF transmission system.

Abstract: A heterogeneous back-off algorithm wherein latency-intolerant messages follow a linear back-off and other messages follow an exponential back-off protocol is disclosed. Typically exponential back-off techniques are used to schedule retransmissions to increase the probability of successful transmission in temporally high contention scenarios. However, exponential back-off can create an exponential increase in the transmit latency. For transmitting latency-intolerant messages like handoff messages large latency is not acceptable therefore a heterogeneous back-off algorithm using both back-off protocols is proposed.

Abstract: An extension to a heterogeneous MAC protocol that makes provisions for multi-frequency system architecture is described. A new frame structure for a multi-frequency xMAX system is introduced. Multi-frequency xMAX system is an extension of a single-channel xMAX system, where the available bandwidth is split into multiple channels to provide additional capacity and range. The new frame structure is followed by all channels and is designed to fulfill the requirements of multiple frequency operation. The new frame structure incorporates features that allow the handset to leverage the advantages of multiple frequency channels, especially in the event of interference. Also, a new mechanism to reduce the power consumption in the handset is discussed that significantly reduces the number of unnecessary receive operations at the handset.

Abstract: This disclosure describes a new Medium Access Control (MAC) protocol that combines contention-free and contention-based MAC protocols into a heterogeneous MAC protocol used for forwarding VoIP traffic in VoIP systems on wireless networks using multiple base stations which addresses the need to transport high bit-rate data to multiple users over wired and wireless means.