We establish a statistical model for the ultra-wide bandwidth (UWB) indoor channel based on an extensive measurement campaign in a typical modern office building with 2-ns delay resolution. The approach is based on the investigation of the statistical properties of the multipath profiles measured in different rooms over a finely spaced measurement grid. The analysis leads to the formulation of a stochastic tapped-delay-line (STDL) model of the UWB indoor channel. The averaged power delay profile can be well-modeled by a single exponential decay with a statistically distributed decay constant. The small-scale statistics of path energy gains follow Gamma distributions whose parameters m are truncated Gaussian variables with mean values and standard deviations decreasing with delay. The total received energy experiences a lognormal shadowing around the mean energy given by the path-loss power law. We also find that the correlation between multipath components is negligible. Finally, we propose an implementation of the STDL model and give a comparison between the experimental data and the simulation results.

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The ultra-wide bandwidth indoor channel: from statistical model to simulations

In this paper, new sum-of-sinusoids statistical simulation models are proposed for Rayleigh fading channels. These new models employ random path gain, random initial phase, and conditional random Doppler frequency for all individual sinusoids. It is shown that the autocorrelations and cross correlations of the quadrature components, and the autocorrelation of the complex envelope of the new simulators match the desired ones exactly, even if the number of sinusoids is as small as a single-digit integer. Moreover, the probability density functions of the envelope and phase, the level crossing rate, the average fade duration, and the autocorrelation of the squared fading envelope which contains fourth-order statistics of the new simulators, asymptotically approach the correct ones as the number of sinusoids approaches infinity, while good convergence is achieved even when the number of sinusoids is as small as eight. The new simulators can be directly used to generate multiple uncorrelated fading waveforms for frequency selective fading channels, multiple-input multiple-output channels, and diversity combining scenarios. Statistical properties of one of the new simulators are evaluated by numerical results, finding good agreements.

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Simulation models with correct statistical properties for Rayleigh fading channels

Methods and systems for transmitting uplink control information and feedback are disclosed for carrier aggregation systems. A user equipment device may be configured to transmit uplink control information and other feedback for several downlink component carriers using one or more uplink component carriers. The user equipment device may be configured to transmit such data using a physical uplink control channel rather than a physical uplink shared channel. The user equipment device may be configured to determine the uplink control information and feedback data that is to be transmitted, the physical uplink control channel resources to be used to transmit the uplink control information and feedback data, and how the uplink control information and feedback data may be transmitted over the physical uplink control channel.

Uplink control data transmission

An improved sum-of-sinusoids simulation model is proposed for Rayleigh fading channels. The new model employs random initial phase, and conditional random Doppler frequency for all individual sinusoids. The second-order statistics of the new simulator match the desired ones exactly even if the number of sinusoids is a single-digit integer. Other key statistics of the new simulator approach the desired ones of Clarke's (1968) reference model as the number of sinusoids approaches infinity, while good convergence is achieved when the number of sinusoids is small. Moreover, the new simulator can be directly used to generate multiple uncorrelated fading waveforms; it is also pointed out that a class of 16 different simulators, which have identical statistical properties, can be developed for Rayleigh fading channels.

Improved models for the generation of multiple uncorrelated Rayleigh fading waveforms

Channel state information is reported in periodic and aperiodic reports for multiple component carriers or serving cells Channel state information may be reported for a subset of aggregated downlink carriers or serving cells For an aperiodic report, the carrier(s)/serving cell(s) for which channel state information is reported are determined based on the request for the aperiodic report When a CQI/PMI/RI report and a HARQ ACK/NACK report coincide in a subframe, the HARQ ACK/NACK report is transmitted on PUCCH, and the CQI/PMI/RI report is transmitted on PUSCH

Channel state information transmission for multiple carriers

Multiple independent Rayleigh fading waveforms are often required for the simulation of wireless communications channels. Jakes (1974) Rayleigh fading model and its derivatives based on the sum-of-sinusoids provide simple simulators, but they have major shortcomings in their simulated correlation functions. A novel sum-of-sinusoids fading model is proposed and verified, which generates Rayleigh fading processes satisfying the theoretical independence requirements and providing desired power spectral densities with ideal second-order moment. The effects of replacing sinusoids in the proposed model by their approximate waveforms are also analyzed and tested. Performance evaluation and comparison are provided, using the quality measures of the mean-square-error of autocorrelation function and the second-order moment of the power spectral density.

The simulation of independent Rayleigh faders

The simulation of wireless communication channels often requires the generation of multiple complex waveforms satisfying the following conditions. (1) The real and imaginary parts are independent zero-mean random Gaussian processes with identical auto-correlation functions. (2) The complex waveforms are independent so that the cross-correlation function between any two waveforms is zero. We first analyze previously proposed methods based on Jakes fading model to demonstrate that the above two conditions have not been satisfied. We then propose a novel method for the generation of multiple Rayleigh faders, which uses improved arrival angle patterns and incident wave phases. The auto-correlation and cross-correlation functions are derived to prove theoretically that the above two conditions are satisfied. Finally the statistical properties are verified by numerical results.

The generation of independent Rayleigh faders

This article presents the solution for decomposing continuous-phase modulated (CPM) signals with integer modulation index into pulse-amplitude modulated components. The notion of main complex pulse is also introduced. A simplified demodulator for CPM signals with integer modulation index is proposed as an application example and simulation results using a quaternary 2 raised cosine (RC) scheme are given.

The PAM decomposition of CPM signals with integer modulation index

A family of complete complementary sets of sequences with closed-form expression is presented in this paper. Firstly, by introducing the notion of Golay (1961)-paired matrix and providing its synthesis algorithms, an orthogonal Golay-paired matrix called Golay-paired Hadamard matrix is derived. Then, general procedures for constructing mutually orthogonal Golay-paired matrices are proposed. Finally, the complete complementary sets of sequences represented by Golay-paired Hadamard matrices are generated and their scalability is illustrated. The unique properties of this new family of scalable complete complementary sets of sequences make it an ideal candidate for applications in future advanced signal processing and communications systems.

Scalable complete complementary sets of sequences

Ultra-wideband technology promises unique advantages over conventional narrowband communications systems. However, the potential interference of ultra-wideband devices to existing narrowband systems is an issue of serious concerns. The mathematical models for describing two impulse modulation schemes, namely the biphase modulation and the hybrid modulation, are reviewed. A period extension method and two implementations for PN sequence in the impulse train used to generate ultrawideband signal are proposed. Considerable reduction in the power spectral density level can be obtained by use of this period extension technique. An example using m-sequence is given, which demonstrates a near-white ultra-wideband spectrum.

Yunxin Li

Papers

The simulation of independent Rayleigh faders

The generation of independent Rayleigh faders

The PAM decomposition of CPM signals with integer modulation index

Scalable complete complementary sets of sequences

Generating near-white ultra-wideband signals with period extended PN sequences