Radio frequency architecture for spectrum access networks
View Patent ↗Radio frequency (RF) architectures for spectrum access networks are provided. Embodiments of the invention generally provide a radio frequency (RF) architecture for customer premise equipment (CPE) for use in, for example, IEEE 802.22 wireless regional area networks (WRANs). In some embodiments, the CPE RF architecture includes two receive chains with a directional antenna and an omni-directional antenna, respectively. The CPE RF architecture facilitates opportunistic out-of-band spectrum sensing and WRAN signal receiving that are performed in parallel with data transmission.
1. A method of operating a coordinated pair of circuits in a Customer Premise Equipment (CPE) in a Wireless Regional Area Network (WRAN) comprising:
providing an out-of-band sensing circuit comprising an omnidirectional sensing antenna, a first tunable pre-selective filter coupled to the omnidirectional sensing antenna, a first low noise amplifier coupled to the first tunable pre-selective filter, a first mixer coupled to the first low noise amplifier, a first tunable local oscillator coupled to the first mixer, a first channel filter coupled to the first mixer, a first WRAN synchronization demodulator module coupled to the first channel filter, and a sensing scheme module coupled to the first channel filter;
operating the first tunable pre-selective filter and the first tunable local oscillator to receive a first common tuning signal;
operating the first WRAN synchronization demodulator module to ignore in-band signals but to detect other, out-of-band, WRAN signals, either from other WRAN base stations, television channels, or from other Customer Premise Equipment;
providing a transmitting and receiving circuit comprising a directional antenna operable both to transmit and receive, a radio frequency (RF) switch coupled to the directional antenna, an in-band demodulation circuit coupled to the RF switch, and an in-band modulation circuit coupled to the RF switch; and
operating the out-of-band sensing circuit at a same time that transmission and reception occurs on the transmitting and receiving circuit between the CPE and a base station to which the CPE is subscribed.
2. A method of operating a Wireless Regional Area Network (WRAN) Customer Premise Equipment (CPE) radio frequency (RF) system, comprising:
providing an out-of-band sensing circuit capable of out-band spectrum sensing comprising an omnidirectional sensing antenna; a first tunable pre-selective filter coupled to the omnidirectional sensing antenna, a first low noise amplifier coupled to the first tunable pre-selective filter, a first mixer coupled to the first low noise amplifier, a first tunable local oscillator coupled to the first mixer, a first channel filter coupled to the first mixer, a first WRAN synchronization demodulator module coupled to the first channel filter, and a sensing scheme module coupled to the first channel filter;
operating the first tunable pre-selective filter and the first tunable local oscillator to receive a first common tuning signal;
operating the first WRAN synchronization demodulator module to ignore in-band signals but to detect other, out-of-band, WRAN signals, either from other WRAN base stations, television channels, or from other Customer Premise Equipment;
providing an in-band WRAN signal transmitting and receiving circuit comprising a directional antenna operable both to transmit and receive, an RF switch coupled to the directional antenna, an in-band demodulation circuit coupled to the RF switch, an in-band modulation circuit coupled to the RF switch; and
operating the out-of-band sensing circuit and the transmitting and receiving circuits to perform, respectively, in parallel, out-band WRAN signal receiving on the omnidirectional antenna, and data transmission and reception on the directional antenna.