摘要:
The performance of forward error correction decoders for digital communication systems can be improved if soft information relating the reliability of the value representing the demodulated signal is provided to the decoder with a value for the signal. On the other hand, soft information increases the quantity of information that must be processed, increasing the cost and complexity of the decoder.
摘要:
A wideband receiver, including a time-varying finite impulse response (FIR) filter, has been provided to combine multipath communications of data in response to pilot channel timing information. The time-varying FIR processes the multipath communications through independent signal paths. Each signal path includes a variable delay circuit and a variable gain circuit. The delay of each separate signal path is adjusted and made equal in response to the pilot channel timing information. Likewise, the gain of each signal path is adjusted in response to pilot channel gain information to maximize the signal to noise ratio of the combined signal paths. The separate signal paths are then summed in a combiner circuit. The time-varying FIR permits the data communication to be summed either before, or after demodulation. A method of combining multipath communications using a time-varying FIR is also provided.
摘要:
Embodiments of the present invention provide for downlink resource allocation among a plurality of users. Other embodiments may be described and claimed.
摘要:
Embodiments of the present invention provide for downlink resource allocation among a plurality of users. Other embodiments may be described and claimed.
摘要:
A wideband CDMA receiver system to accept messages from asynchronously transmitting base stations is provided. The base station transmission to each receiver includes a perch channel and at least one traffic channel. Although all the channels typically include pilot symbols for the purpose of demodulating the information symbols of the channel, the pilot channel includes a higher proportion of pilot symbols to information symbols. Therefore, a perch channel based timing and estimation system is inherently more accurate. In addition, the perch channel is generally transmitted at higher power levels than a traffic channel, and the resulting, higher, signal to noise ratio signal also improves the accuracy of the timing and channel estimation. Based on the timing derived from the perch channel of a first base station, the receiver can set the timing of the traffic channel transmissions from a second base station, to more closely match the timing of traffic channel transmissions from the first base station. In this manner, the signal to noise ratio of the demodulated traffic channel information symbols is enhanced through the diversity of using the transmissions of two base stations. A method for receiving wideband CDMA transmissions from asynchronously transmitting base stations is also provided.
摘要:
Techniques are described to transmit multimedia content to a mobile station using a combination of a mobile/cellular network as well as a TV Whitespace (TVWS) network. Scalable video coding can be used to transmit a baseline layer of multi-media content using the mobile/cellular network and one or more enhancement layers over the TVWS channels. Joint source-channel coding can be used to adjust the transmission scheme used by mobile/cellular and/or TVWS based on end user experience.
摘要:
Techniques are described to transmit multimedia content to a mobile station using a combination of a mobile/cellular network as well as a TV Whitespace (TVWS) network. Scalable video coding can be used to transmit a baseline layer of multi-media content using the mobile/cellular network and one or more enhancement layers over the TVWS channels. Joint source-channel coding can be used to adjust the transmission scheme used by mobile/cellular and/or TVWS based on end user experience.
摘要:
In a direct sequence spread spectrum data communication system an information bit is mixed with a pseudorandom noise or spreading code to produce modulated codeword for transmission. A method of bandwidth efficient M-ary phase shift key modulation encoding at least 16 bits of data to a single codeword is disclosed for extending the data rate of a spread spectrum system. Interoperability with legacy devices is maximized by maintaining structural similarity between the modulated waveforms of the extended data rate and legacy systems.
摘要:
An adaptive CDMA sequential detection method is provided. The method permits the use of the sequential detection process to determine an unknown spreading code in an environment where the signal to noise ratio of the received signal varies. A communication system, such as W-CDMA, provides a periodic reference signal that the receiver can demodulate without the spreading code. The reference signal is used to estimate and constantly update the signal to noise calculation. From this estimate a bias is updated for use in the sequential detection of the spreading code. A system to update the CDMA sequential detector bias value is also provided.
摘要:
Embodiments of the present invention provide for downlink resource allocation among a plurality of users. Other embodiments may be described and claimed.