A method of wireless communication includes monitoring coexistence issues among supported radios in a User Equipment (UE). The method includes determining a coexistence policy for communication resource operation within a user equipment (UE) and configuring communication resources of the user equipment in accordance with the determined coexistence policy. The policy may give priority to an LTE modem, an ISM modem, or may implement a variable priority scheme. The policy may be communicated to each modem from a host over a software messaging communication line. Modems in the UE may communicate with each other through logical lines providing real time communication. The policy may determine the operation of each modem and the treatment of the logical lines by each modem.

Method and apparatus to facilitate support for multi-radio coexistence

A preamble portion of a physical layer (PHY) data unit is generated for transmission via a long range communication protocol. A service field is generated with a length of eight or less bits. A data portion of the PHY data unit is generated to include the service field having the length of eight bits or less.

Physical layer frame format for long range wlan

We evaluate the throughput performance of an OFDM WiMAX (IEEE 802.16-2004, Section 8.3) transmission system with adaptive modulation and coding (AMC) by outdoor measurements. The standard compliant AMC utilizes a 3-bit feedback for SISO and Alamouti coded MIMO transmissions. By applying a 6-bit feedback and spatial multiplexing with individual AMC on the two transmit antennas, the data throughput can be increased significantly for large SNR values. Our measurements show that at small SNR values, a single antenna transmission often outperforms an Alamouti transmission. We found that this effect is caused by the asymmetric behavior of the wireless channel and by poor channel knowledge in the two-transmit-antenna case. Our performance evaluation is based on a measurement campaign employing the Vienna MIMO testbed. The measurement scenarios include typical outdoor-to-indoor NLOS, outdoor-to-outdoor NLOS, as well as outdoor-to-indoor LOS connections. We found that in all these scenarios, the measured throughput is far from its achievable maximum; the loss is mainly caused by a too simple convolutional coding.

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Experimental Evaluation of Adaptive Modulation and Coding in MIMO WiMAX with Limited Feedback

Network re-selection by an idle mobile device between multiple radio access technologies (RATs) is provided for communication networks without a network-based solution. When a user equipment (UE) enters idle mode while camped to a first RAT network, it initiates an out of service search procedure that causes the UE to search for other RATs within a same public land mobile network (PLMN). If another RAT network is detected, the UE determines whether the priority of the detected RAT is higher than the priority of the first RAT. When the detected RAT has a higher priority than the first RAT, the UE re-selects and camps to that detected RAT network. If the detected RAT does not have a higher priority or no other RAT is detected within the PLMN, the UE re-camps to the first RAT network.

Transitioning of mobile devices within a wireless communication network between multiple radio access technologies

Embodiments of the present invention are directed to the invocation of active states and power conservation states in accordance with the standard or diluted beacon periods defined in beacon frames. Active periods, or “awake windows,” may be defined by additional information (e.g., information elements) that is included in the beacon. Awake windows may establish periods of time during which apparatuses may contend for access to a wireless communication medium. A methodology may further be employed to help determine which apparatuses will have priority when accessing the communication medium. This criteria may be used alone or in combination with the corresponding standard channel access rules (e.g., contention) that govern operation of the particular wireless communication medium in order to control how apparatuses communicate and interact in the wireless network.

Power management in wireless communication systems

Mobile WiMAX systems are based on the IEEE 802.16e specifications, which include two mandatory MIMO profiles for the downlink. One of these is Alamouti's space-time code (STC) for transmit diversity, and the other is a 2times2 spatial multiplexing MIMO scheme. In this paper, we compare the two schemes assuming that the latter employs maximum-likelihood detection. The analysis shows that at the same spectral efficiency, Alamouti's STC combined with maximum-ratio combining (MRC) at the receiver significantly outperforms the 2times2 spatial multiplexing scheme at high values of the signal-to-noise ratio (SNR). Next, selection of a MIMO option is included in link adaptation to maximize network capacity, and operating SNR regions are determined for different modulation, coding and MIMO combinations.

MIMO Link Adaptation in Mobile WiMAX Systems

A method and apparatus are provided for radio access technology (RAT) monitoring, in a wireless system environment having wireless communications equipment and at least two different RATs that coexist for providing to the equipment access to one or more communications networks. The equipment has at least two subsystems, each adapted for establishing and maintaining an active communications connection with a certain one of the different RATs. The equipment selects at least a first RAT, among all the RATs available in a certain geographical area, for establishing the active communications connection, according to a monitored characteristic of the first RAT. The method includes scanning a characteristic of a second RAT available for communication in the geographical area while the equipment maintains an active communications connection with the first RAT, and performing the scanning step when the equipment does not transmit signals through the active communications connection maintained with the first RAT.

Method and system for radio access technology monitoring in a wireless communications system

Multiple input multiple output (MIMO) techniques are an essential part of the IEEE 802.16e-2005 specifications, which form the basis of mobile WiMAX systems. In this paper, we first discuss the tradeoffs between diversity, interference cancellation and spatial multiplexing in MIMO systems, and we compare optimum combining (OC), maximum-ratio combining (MRC) and interference cancellation for different numbers of receive antennas. Then, we focus on the two mandatory MIMO profiles in the IEEE specifications (Alamouti's STC and the 2x2 spatial multiplexing scheme) and compare them when the first is combined with MRC at the receiver. The analysis obtained using the ITU pedestrian B channel in ideal conditions indicates that the two schemes lead to similar performance when they are operated at the same spectral efficiency

Diversity, interference cancellation and spatial multiplexing in MIMO mobile WiMAX systems

This chapter contains sections titled: Introduction Multiple Antenna Systems M Multiple Antennas in WiMAX Systems Conclusion References

An Analysis of MIMO Techniques for Mobile WiMAX Systems

User equipment is provided for receiving an OFDM signal. The user equipment includes a plurality of carrier processing chains and a carrier aggregation module, aggregating the signals received on each carrier processed by the plurality of carrier processing chains. The aggregation module delivers a set of aggregated signals of the plurality of carrier processing chains at the input of a Fast Fourier Transform module of a PHY layer processing subsystem of the user equipment. The Fast Fourier transform module is able to process a size of data according to a predetermined rate depending on the aggregated bandwidth of the set of aggregated signals of the plurality of carrier processing chains, and the carrier aggregation module includes at least one frequency shifter for frequency shifting carriers.

Bertrand Muquet

Papers

MIMO Link Adaptation in Mobile WiMAX Systems

Method and system for radio access technology monitoring in a wireless communications system

Diversity, interference cancellation and spatial multiplexing in MIMO mobile WiMAX systems

An Analysis of MIMO Techniques for Mobile WiMAX Systems

Method and user equipment for carrier aggregation