Sensitive White Space Detection with Spectral Covariance Sensing

This paper proposes a novel, highly effective spectrum sensing algorithm for cognitive radio and whitespace applications. The proposed spectral covariance sensing (SCS) algorithm exploits the different statistical correlations of the received signal and noise in the frequency domain. Test statistics are computed from the covariance matrix of a partial spectrogram and compared with a decision threshold to determine whether a primary signal or arbitrary type is present or not. This detector is analyzed theoretically and verified through realistic open-source simulations using actual digital television signals captured in the US. Compared to the state of the art in the literature, SCS improves sensitivity by 3 dB for the same dwell time, which is a very significant improvement for this application. Further, it is shown that SCS is highly robust to noise uncertainty, whereas many other spectrum sensors are not

Marital Investments and Community Involvement: A Test of Coser’s Greedy Marriage Thesis

It is customary to test Coser’s greedy marriage thesis by comparing marital status groups. We propose a new approach that uses the marital dyad as the unit of analysis and examine whether investments in the marital relationship discourage community involvement through formal volunteering. Data from a U.S. national sample of 1,368 married couples revealed mixed support for the proposed relationship. Consistent with the greedy marriage thesis, wives’ soulmate view of marriage was negatively associated with their own and their husbands’ reports of volunteering. Although these associations were attenuated by religious service attendance, wives’ soulmate view had a more dampening effect than husbands’ soulmate view on their own and their husbands’ volunteering. However, the time couples spend alone together was positively associated with husbands’ reports of volunteering, which counters the greedy marriage thesis. These findings suggest that the greedy nature of marriage is, in part, determined by its participants—how they define and manage their marriage

Consumption Risk-sharing within Australia and with New Zealand

quantify how output risks are smoothed within Australia, and between Australia and New Zealand. About 85 percent of shocks were smoothed within Australia through credit and capital markets, with fiscal policy a source of dis-smoothing after 1992. Risk-sharing between Australia and New Zealand was greater than within Europe, occurring mostly through credit markets. With fully integrated financial markets between Australia and New Zealand since 1960, the average welfare gain would be 2.7 percent of certainty-equivalent consumption over 50 years, although these gains favour New Zealand. Australia's gains are from the pooling of PPP risks. These potential gains were largely resolved by the deregulations and CER trade agreement of the early198 0s.Risk-sharing; horizontal fiscal equalization; common currency; welfare gains from integration

Central Bank Interventions in the Yen-Dollar Spot Market

We test the effectiveness of Bank of Japan (BOJ)'s foreign exchange interventions on conditional first and second moments of exchange rate returns and traded volumes, using a bivariate EGARCH model of the Yen/USD market from 5-13-1991 to 6-28-2002. We also estimate a friction model of BOJ's intervention reaction function based on reducing short-term market disorderliness and supplementing domestic monetary policy. We find ineffectiveness of BOJ interventions pre-1995 but effectiveness post-1995, Fed intervention amplified the effectiveness of the BOJ transactions, BOJ's interventions were based on ‘leaning against the wind' motivations, and BOJ interventions were vigorously used in support of domestic monetary policy objectives pos t-1995.Foreign exchange intervention; Bank of Japan; exchange rate volatility; trade volume