Agere Systems Inc.

Motorola Mobility LLC

Kai Roland Kriedte

Jan Boer

Bas Driesen

Ra'anan Gil

Robert John Kopmeiners

Wilhelmus Diepstraten

Paul F Struhsaker

D J Richard Van Nee

Adriaan Kamerman

Tim Schenk

Allert Van Zelst

Rienk Mud

Wim J Diepstraten

Jaap Van Der Plas

Henk Van Bokhorst

A method for controlling a transmission rate of at least one transceiver, the transceiver including a transmitter and a receiver, includes: determining a signal quality characteristic corresponding to a signal received at the receiver by measuring a difference between one or more reference constellation points and one or more received constellation points, and modifying a transmission rate of the transmitter over a wireless communication channel as a function of the signal quality characteristic. The step of modifying the transmission rate over the wireless communication channel includes: determining lower and upper threshold levels representing reference minimum and maximum signal quality characteristics, respectively, corresponding to the transmission rate; maintaining the transmission rate when the measured signal quality characteristic is between the lower and upper threshold levels; and increasing the transmission rate when the signal quality characteristic is less than one or more lower threshold levels associated with one or more corresponding higher transmission rates.

Data transmission rate adaptation in a wireless communication system

In a wireless system including a wireless communication channel, a method for estimating a signal quality of a received signal includes the steps of receiving a signal from the wireless communication channel, the received signal including at least one field that is modulated and encoded in a substantially fixed manner, and generating at least one reference field based, at least in part, on the at least one field and on a channel estimation signal. The channel estimation signal is representative of at least one characteristic of the wireless communication channel. The method further includes the step of generating a signal quality estimate as a function of the at least one field in the received signal and the generated at least one reference field.

Signal quality estimation in a wireless communication system

A technique for providing broadcast services to a subscriber station includes determining () when a first broadcast frame that is to be transmitted on a broadcast channel includes broadcast information that is to be received by the subscriber station. Next, cellular information that is included within a first cellular frame and that is to be received by the subscriber station is scheduled (), based on the determining, to avoid conflict between receipt of the cellular information and the broadcast information at the subscriber station. Finally, based on the scheduling, the first cellular frame is transmitted () on a cellular channel.

Technique for providing broadcast services in a cellular network

A method and apparatus are disclosed for detecting a collision in a carrier sense multiple access wireless communication system. Each transmitting station includes a collision detector that evaluates one or more predefined criteria to determine when a collision has occurred. The collision detector evaluates the measured energy level and optionally payload and/or preamble detection information to determine if a collision has occurred. A collision occurred when an expected ACK message is not received, in the presence of an increased energy level and possibly preamble or payload detection information. The collision detector of the present invention can be activated, for example, at a time corresponding to the start of the 802.11 Short Inter Frame Space interval.

Method and apparatus for detecting a collision in a carrier sense multiple access wireless system

In a wireless system comprising at least one transceiver configurable for communication over a wireless communication channel, the transceiver comprising a transmitter and a receiver, a method for controlling a data transmission rate of the at least one transceiver comprises the steps of: (i) determining a signal quality characteristic corresponding to a signal received at the receiver by measuring a difference between one or more reference constellation points and one or more received constellation points, the signal quality characteristic representing an estimation of signal degradation; and (ii) modifying a data transmission rate of the transmitter based, at least in part, on the signal quality characteristic.

Medium access control device () for a mobile network station () or an access point (AP) in a wireless local area network (), having controlling means (), processing means () and transmitting and receiving means (); the controlling means () being arranged to control transmission and reception of radio frequency data signals containing data symbols; the transmitting and receiving means () being arranged for transmission and reception of electromagnetic data signals; the processing means () being arranged for detecting a first signal portion and a second signal portion in the received data signal, the second signal portion following the first signal portion and having a signal coding differing from a signal coding of the first signal portion.

Wireless LAN with enhanced carrier sensing

Symbol timing for a wireless communication system, such as a multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) wireless LAN system, is determined by summing the powers for an appropriate set of channel impulse responses, integrating this power summation over an appropriate window (e.g., equivalent to the guard interval), and identifying the time at which the maximum integration occurs. Depending on the implementation, symbol timing can be determined for each receiver branch individually or for all receiver branches jointly. In either case, the determined symbol timing(s) can minimize the amount of inter-symbol and inter-channel interferences that are invoked in the system.

Symbol timing for MIMO OFDM and other wireless communication systems

A system for operating a communication system comprising one or more transmitters and receivers. The transmitted signals are provided with a preamble for training the receiver and/or the transmitter being in communication. The quality of the received signal is measured and compared with a threshold. If the quality is higher or lower than said threshold, a short preamble processing or a long preamble processing, respectively, is used. More than one threshold and associated pairs of preambles having different length may be used.

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Woerden, Netherlands

Kai Roland Kriedte